IntroductionApache Camel ™ is a versatile open-source integration framework (with powerful Bean Integration) based on known Enterprise Integration Patterns.Camel empowers you to define routing and mediation rules in a variety of domain-specific languages, including a Java-based Fluent API, Spring or Blueprint XML Configuration files, and a Scala DSL. This means you get smart completion of routing rules in your IDE, whether in a Java, Scala or XML editor. Apache Camel uses URIs to work directly with any kind of Transport or messaging model such as HTTP, ActiveMQ, JMS, JBI, SCA, MINA or CXF, as well as pluggable Components and Data Format options. Apache Camel is a small library with minimal dependencies for easy embedding in any Java application. Apache Camel lets you work with the same API regardless which kind of Transport is used - so learn the API once and you can interact with all the Components provided out-of-box. Apache Camel has powerful Bean Binding and seamless integration with popular frameworks such as Spring, Blueprint and Guice. Camel also has extensive support for unit testing your routes. The following projects can leverage Apache Camel as a routing and mediation engine:
So don't get the hump - try Camel today!
QuickstartTo start using Apache Camel quickly, you can read through some simple examples in this chapter. For readers who would like a more thorough introduction, please skip ahead to Chapter 3. Walk through an Example CodeThis mini-guide takes you through the source code of a simple example. Camel can be configured either by using Spring or directly in Java - which this example does. This example is available in the examples\camel-example-jms-file directory of the Camel distribution. We start with creating a CamelContext - which is a container for Components, Routes etc: CamelContext context = new DefaultCamelContext();
There is more than one way of adding a Component to the CamelContext. You can add components implicitly - when we set up the routing - as we do here for the FileComponent: context.addRoutes(new RouteBuilder() { public void configure() { from("test-jms:queue:test.queue").to("file://test"); } }); or explicitly - as we do here when we add the JMS Component: ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("vm://localhost?broker.persistent=false"); // Note we can explicit name the component context.addComponent("test-jms", JmsComponent.jmsComponentAutoAcknowledge(connectionFactory)); The above works with any JMS provider. If we know we are using ActiveMQ we can use an even simpler form using the activeMQComponent() method while specifying the brokerURL used to connect to ActiveMQ camelContext.addComponent("activemq", activeMQComponent("vm://localhost?broker.persistent=false")); In normal use, an external system would be firing messages or events directly into Camel through one if its Components but we are going to use the ProducerTemplate which is a really easy way for testing your configuration: ProducerTemplate template = context.createProducerTemplate(); Next you must start the camel context. If you are using Spring to configure the camel context this is automatically done for you; though if you are using a pure Java approach then you just need to call the start() method camelContext.start(); This will start all of the configured routing rules. So after starting the CamelContext, we can fire some objects into camel: for (int i = 0; i < 10; i++) { template.sendBody("test-jms:queue:test.queue", "Test Message: " + i); } What happens?From the ProducerTemplate - we send objects (in this case text) into the CamelContext to the Component test-jms:queue:test.queue. These text objects will be converted automatically into JMS Messages and posted to a JMS Queue named test.queue. When we set up the Route, we configured the FileComponent to listen of the test.queue. The File FileComponent will take messages off the Queue, and save them to a directory named test. Every message will be saved in a file that corresponds to its destination and message id. Finally, we configured our own listener in the Route - to take notifications from the FileComponent and print them out as text. That's it! If you have the time then use 5 more minutes to Walk through another example that demonstrates the Spring DSL (XML based) routing.
Walk through another exampleIntroductionWe continue the walk from Walk through an Example. This time we take a closer look at the routing and explains a few pointers so you wont walk into a bear trap, but can enjoy a walk after hours to the local pub for a large beer First we take a moment to look at the Enterprise Integration Patterns that is the base pattern catalog for integrations. In particular we focus on the Pipes and Filters EIP pattern, that is a central pattern. This is used for: route through a sequence of processing steps, each performing a specific function - much like the Java Servlet Filters. Pipes and filtersIn this sample we want to process a message in a sequence of steps where each steps can perform their specific function. In our example we have a JMS queue for receiving new orders. When an order is received we need to process it in several steps:
This can be created in a route like this: <route> <from uri="jms:queue:order"/> <pipeline> <bean ref="validateOrder"/> <bean ref="registerOrder"/> <bean ref="sendConfirmEmail"/> </pipeline> </route>
Where as the bean ref is a reference for a spring bean id, so we define our beans using regular Spring XML as:
<bean id="validateOrder" class="com.mycompany.MyOrderValidator"/>
Our validator bean is a plain POJO that has no dependencies to Camel what so ever. So you can implement this POJO as you like. Camel uses rather intelligent Bean Binding to invoke your POJO with the payload of the received message. In this example we will not dig into this how this happens. You should return to this topic later when you got some hands on experience with Camel how it can easily bind routing using your existing POJO beans. So what happens in the route above. Well when an order is received from the JMS queue the message is routed like Pipes and Filters: Using Camel ComponentsIn the route lets imagine that the registration of the order has to be done by sending data to a TCP socket that could be a big mainframe. As Camel has many Components we will use the camel-mina component that supports TCP connectivity. So we change the route to: <route> <from uri="jms:queue:order"/> <bean ref="validateOrder"/> <to uri="mina:tcp://mainframeip:4444?textline=true"/> <bean ref="sendConfirmEmail"/> </route> What we now have in the route is a to type that can be used as a direct replacement for the bean type. The steps is now: What to notice here is that the to is not the end of the route (the world <route> <from uri="jms:queue:order"/> <to uri="bean:validateOrder"/> <to uri="mina:tcp://mainframeip:4444?textline=true"/> <to uri="bean:sendConfirmEmail"/> </route> As the to is a generic type we must state in the uri scheme which component it is. So we must write bean: for the Bean component that we are using. ConclusionThis example was provided to demonstrate the Spring DSL (XML based) as opposed to the pure Java DSL from the first example. And as well to point about that the to doesn't have to be the last node in a route graph. This example is also based on the in-only message exchange pattern. What you must understand as well is the in-out message exchange pattern, where the caller expects a response. We will look into this in another example. See alsoThe Enterprise Integration Patterns (EIP) bookThe purpose of a "patterns" book is not to advocate new techniques that the authors have invented, but rather to document existing best practices within a particular field. By doing this, the authors of a patterns book hope to spread knowledge of best practices and promote a vocabulary for discussing architectural designs. The Camel projectCamel (http://camel.apache.org) is an open-source, Java-based project that helps the user implement many of the design patterns in the EIP book. Because Camel implements many of the design patterns in the EIP book, it would be a good idea for people who work with Camel to have the EIP book as a reference. Online documentation for CamelThe documentation is all under the Documentation category on the right-side menu of the Camel website (also available in PDF form. Camel-related books are also available, in particular the Camel in Action book, presently serving as the Camel bible--it has a free Chapter One (pdf), which is highly recommended to read to get more familiar with Camel. A useful tip for navigating the online documentationThe breadcrumbs at the top of the online Camel documentation can help you navigate between parent and child subsections. Apache Camel > Documentation > Architecture > Languages As you might expect, clicking on "Apache Camel" takes you back to the home page of the Apache Camel project, and clicking on "Documentation" takes you to the main documentation page. You can interpret the "Architecture" and "Languages" buttons as indicating you are in the "Languages" section of the "Architecture" chapter. Adding browser bookmarks to pages that you frequently reference can also save time. Online Javadoc documentationThe Apache Camel website provides Javadoc documentation. It is important to note that the Javadoc documentation is spread over several independent Javadoc hierarchies rather than being all contained in a single Javadoc hierarchy. In particular, there is one Javadoc hierarchy for the core APIs of Camel, and a separate Javadoc hierarchy for each component technology supported by Camel. For example, if you will be using Camel with ActiveMQ and FTP then you need to look at the Javadoc hierarchies for the core API and Spring API. Concepts and terminology fundamental to CamelIn this section some of the concepts and terminology that are fundamental to Camel are explained. This section is not meant as a complete Camel tutorial, but as a first step in that direction. EndpointThe term endpoint is often used when talking about inter-process communication. For example, in client-server communication, the client is one endpoint and the server is the other endpoint. Depending on the context, an endpoint might refer to an address, such as a host:port pair for TCP-based communication, or it might refer to a software entity that is contactable at that address. For example, if somebody uses "www.example.com:80" as an example of an endpoint, they might be referring to the actual port at that host name (that is, an address), or they might be referring to the web server (that is, software contactable at that address). Often, the distinction between the address and software contactable at that address is not an important one.
Because of this, you can see that the term endpoint is ambiguous in at least two ways. First, it is ambiguous because it might refer to an address or to a software entity contactable at that address. Second, it is ambiguous in the granularity of what it refers to: a heavyweight versus lightweight software entity, or physical address versus logical address. It is useful to understand that different people use the term endpoint in slightly different (and hence ambiguous) ways because Camel's usage of this term might be different to whatever meaning you had previously associated with the term.
In a Camel-based application, you create (Camel wrappers around) some endpoints and connect these endpoints with routes, which I will discuss later in Section 4.8 ("Routes, RouteBuilders and Java DSL"). Camel defines a Java interface called Endpoint. Each Camel-supported endpoint has a class that implements this Endpoint interface. As I discussed in Section 3.3 ("Online Javadoc documentation"), Camel provides a separate Javadoc hierarchy for each communications technology supported by Camel. Because of this, you will find documentation on, say, the JmsEndpoint class in the JMS Javadoc hierarchy, while documentation for, say, the FtpEndpoint class is in the FTP Javadoc hierarchy. CamelContextA CamelContext object represents the Camel runtime system. You typically have one CamelContext object in an application. A typical application executes the following steps.
Note that the CamelContext.start() operation does not block indefinitely. Rather, it starts threads internal to each Component and Endpoint and then start() returns. Conversely, CamelContext.stop() waits for all the threads internal to each Endpoint and Component to terminate and then stop() returns. CamelTemplateCamel used to have a class called CamelClient, but this was renamed to be CamelTemplate to be similar to a naming convention used in some other open-source projects, such as the TransactionTemplate and JmsTemplate classes in Spring. The Meaning of URL, URI, URN and IRISome Camel methods take a parameter that is a URI string. Many people know that a URI is "something like a URL" but do not properly understand the relationship between URI and URL, or indeed its relationship with other acronyms such as IRI and URN. ComponentsComponent is confusing terminology; EndpointFactory would have been more appropriate because a Component is a factory for creating Endpoint instances. For example, if a Camel-based application uses several JMS queues then the application will create one instance of the JmsComponent class (which implements the Component interface), and then the application invokes the createEndpoint() operation on this JmsComponent object several times. Each invocation of JmsComponent.createEndpoint() creates an instance of the JmsEndpoint class (which implements the Endpoint interface). Actually, application-level code does not invoke Component.createEndpoint() directly. Instead, application-level code normally invokes CamelContext.getEndpoint(); internally, the CamelContext object finds the desired Component object (as I will discuss shortly) and then invokes createEndpoint() on it.
myCamelContext.getEndpoint("pop3://john.smith@mailserv.example.com?password=myPassword");
The parameter to getEndpoint() is a URI. The URI prefix (that is, the part before ":") specifies the name of a component. Internally, the CamelContext object maintains a mapping from names of components to Component objects. For the URI given in the above example, the CamelContext object would probably map the pop3 prefix to an instance of the MailComponent class. Then the CamelContext object invokes createEndpoint("pop3://john.smith@mailserv.example.com?password=myPassword") on that MailComponent object. The createEndpoint() operation splits the URI into its component parts and uses these parts to create and configure an Endpoint object. Component mailComponent = new org.apache.camel.component.mail.MailComponent(); myCamelContext.addComponent("pop3", mailComponent); myCamelContext.addComponent("imap", mailComponent); myCamelContext.addComponent("smtp", mailComponent); The second (and preferred) way to populate the map of named Component objects in the CamelContext object is to let the CamelContext object perform lazy initialization. This approach relies on developers following a convention when they write a class that implements the Component interface. I illustrate the convention by an example. Let's assume you write a class called com.example.myproject.FooComponent and you want Camel to automatically recognize this by the name "foo". To do this, you have to write a properties file called "META-INF/services/org/apache/camel/component/foo" (without a ".properties" file extension) that has a single entry in it called class, the value of which is the fully-scoped name of your class. This is shown below. META-INF/services/org/apache/camel/component/foo class=com.example.myproject.FooComponent If you want Camel to also recognize the class by the name "bar" then you write another properties file in the same directory called "bar" that has the same contents. Once you have written the properties file(s), you create a jar file that contains the com.example.myproject.FooComponent class and the properties file(s), and you add this jar file to your CLASSPATH. Then, when application-level code invokes createEndpoint("foo:...") on a CamelContext object, Camel will find the "foo"" properties file on the CLASSPATH, get the value of the class property from that properties file, and use reflection APIs to create an instance of the specified class.
myCamelContext.getEndpoint("pop3://john.smith@mailserv.example.com?password=myPassword");
When I originally gave that example, I said that the parameter to getEndpoint() was a URI. I said that because the online Camel documentation and the Camel source code both claim the parameter is a URI. In reality, the parameter is restricted to being a URL. This is because when Camel extracts the component name from the parameter, it looks for the first ":", which is a simplistic algorithm. To understand why, recall from Section 4.4 ("The Meaning of URL, URI, URN and IRI") that a URI can be a URL or a URN. Now consider the following calls to getEndpoint. myCamelContext.getEndpoint("pop3:..."); myCamelContext.getEndpoint("jms:..."); myCamelContext.getEndpoint("urn:foo:..."); myCamelContext.getEndpoint("urn:bar:..."); Camel identifies the components in the above example as "pop3", "jms", "urn" and "urn". It would be more useful if the latter components were identified as "urn:foo" and "urn:bar" or, alternatively, as "foo" and "bar" (that is, by skipping over the "urn:" prefix). So, in practice you must identify an endpoint with a URL (a string of the form "<scheme>:...") rather than with a URN (a string of the form "urn:<scheme>:..."). This lack of proper support for URNs means the you should consider the parameter to getEndpoint() as being a URL rather than (as claimed) a URI. Message and ExchangeThe Message interface provides an abstraction for a single message, such as a request, reply or exception message. ProcessorThe Processor interface represents a class that processes a message. The signature of this interface is shown below. Processor package org.apache.camel; public interface Processor { void process(Exchange exchange) throws Exception; } Notice that the parameter to the process() method is an Exchange rather than a Message. This provides flexibility. For example, an implementation of this method initially might call exchange.getIn() to get the input message and process it. If an error occurs during processing then the method can call exchange.setException(). Routes, RouteBuilders and Java DSLA route is the step-by-step movement of a Message from an input queue, through arbitrary types of decision making (such as filters and routers) to a destination queue (if any). Camel provides two ways for an application developer to specify routes. One way is to specify route information in an XML file. A discussion of that approach is outside the scope of this document. The other way is through what Camel calls a Java DSL (domain-specific language). Introduction to Java DSLFor many people, the term "domain-specific language" implies a compiler or interpreter that can process an input file containing keywords and syntax specific to a particular domain. This is not the approach taken by Camel. Camel documentation consistently uses the term "Java DSL" instead of "DSL", but this does not entirely avoid potential confusion. The Camel "Java DSL" is a class library that can be used in a way that looks almost like a DSL, except that it has a bit of Java syntactic baggage. You can see this in the example below. Comments afterwards explain some of the constructs used in the example. Example of Camel's "Java DSL" RouteBuilder builder = new RouteBuilder() { public void configure() { from("queue:a").filter(header("foo").isEqualTo("bar")).to("queue:b"); from("queue:c").choice() .when(header("foo").isEqualTo("bar")).to("queue:d") .when(header("foo").isEqualTo("cheese")).to("queue:e") .otherwise().to("queue:f"); } }; CamelContext myCamelContext = new DefaultCamelContext(); myCamelContext.addRoutes(builder); The first line in the above example creates an object which is an instance of an anonymous subclass of RouteBuilder with the specified configure() method. Critique of Java DSLThe online Camel documentation compares Java DSL favourably against the alternative of configuring routes and endpoints in a XML-based Spring configuration file. In particular, Java DSL is less verbose than its XML counterpart. In addition, many integrated development environments (IDEs) provide an auto-completion feature in their editors. This auto-completion feature works with Java DSL, thereby making it easier for developers to write Java DSL. Continue Learning about CamelReturn to the main Getting Started page for additional introductory reference information. ArchitectureCamel uses a Java based Routing Domain Specific Language (DSL) or an Xml Configuration to configure routing and mediation rules which are added to a CamelContext to implement the various Enterprise Integration Patterns. At a high level Camel consists of a CamelContext which contains a collection of Component instances. A Component is essentially a factory of Endpoint instances. You can explicitly configure Component instances in Java code or an IoC container like Spring or Guice, or they can be auto-discovered using URIs. An Endpoint acts rather like a URI or URL in a web application or a Destination in a JMS system; you can communicate with an endpoint; either sending messages to it or consuming messages from it. You can then create a Producer or Consumer on an Endpoint to exchange messages with it. The DSL makes heavy use of pluggable Languages to create an Expression or Predicate to make a truly powerful DSL which is extensible to the most suitable language depending on your needs. The following languages are supported
Most of these languages is also supported used as Annotation Based Expression Language. For a full details of the individual languages see the Language Appendix URIsCamel makes extensive use of URIs to allow you to refer to endpoints which are lazily created by a Component if you refer to them within Routes Current Supported URIs
URI's for external componentsOther projects and companies have also created Camel components to integrate additional functionality into Camel. These components may be provided under licenses that are not compatible with the Apache License, use libraries that are not compatible, etc... These components are not supported by the Camel team, but we provide links here to help users find the additional functionality.
For a full details of the individual components see the Component Appendix Enterprise Integration PatternsCamel supports most of the Enterprise Integration Patterns from the excellent book of the same name by Gregor Hohpe and Bobby Woolf. Its a highly recommended book, particularly for users of Camel. Pattern IndexThere now follows a list of the Enterprise Integration Patterns from the book along with examples of the various patterns using Apache Camel Messaging Systems
Messaging Channels
Message Construction
Message Routing
Message Transformation
Messaging Endpoints
System Management
For a full breakdown of each pattern see the Book Pattern Appendix CookBookThis document describes various recipes for working with Camel
Bean IntegrationCamel supports the integration of beans and POJOs in a number of ways AnnotationsIf a bean is defined in Spring XML or scanned using the Spring component scanning mechanism and a <camelContext> is used or a CamelBeanPostProcessor then we process a number of Camel annotations to do various things such as injecting resources or producing, consuming or routing messages.
Bean ComponentThe Bean component allows one to invoke a particular method. Alternately the Bean component supports the creation of a proxy via ProxyHelper to a Java interface; which the implementation just sends a message containing a BeanInvocation to some Camel endpoint. Spring RemotingWe support a Spring Remoting provider which uses Camel as the underlying transport mechanism. The nice thing about this approach is we can use any of the Camel transport Components to communicate between beans. It also means we can use Content Based Router and the other Enterprise Integration Patterns in between the beans; in particular we can use Message Translator to be able to convert what the on-the-wire messages look like in addition to adding various headers and so forth.
Annotation Based Expression LanguageYou can also use any of the Languages supported in Camel to bind expressions to method parameters when using Bean Integration. For example you can use any of these annotations:
Example:public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@XPath("/foo/bar/text()") String correlationID, @Body String body) { // process the inbound message here } } Advanced example using @BeanAnd an example of using the the @Bean binding annotation, where you can use a Pojo where you can do whatever java code you like: public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@Bean("myCorrelationIdGenerator") String correlationID, @Body String body) { // process the inbound message here } } And then we can have a spring bean with the id myCorrelationIdGenerator where we can compute the id. public class MyIdGenerator { private UserManager userManager; public String generate(@Header(name = "user") String user, @Body String payload) throws Exception { User user = userManager.lookupUser(user); String userId = user.getPrimaryId(); String id = userId + generateHashCodeForPayload(payload); return id; } } The Pojo MyIdGenerator has one public method that accepts two parameters. However we have also annotated this one with the @Header and @Body annotation to help Camel know what to bind here from the Message from the Exchange being processed. Of course this could be simplified a lot if you for instance just have a simple id generator. But we wanted to demonstrate that you can use the Bean Binding annotations anywhere. public class MySimpleIdGenerator { public static int generate() { // generate a unique id return 123; } } And finally we just need to remember to have our bean registered in the Spring Registry:
<bean id="myCorrelationIdGenerator" class="com.mycompany.MySimpleIdGenerator"/>
Example using GroovyIn this example we have an Exchange that has a User object stored in the in header. This User object has methods to get some user information. We want to use Groovy to inject an expression that extracts and concats the fullname of the user into the fullName parameter.
public void doSomething(@Groovy("$request.header['user'].firstName $request.header['user'].familyName) String fullName, @Body String body) {
// process the inbound message here
}
Groovy supports GStrings that is like a template where we can insert $ placeholders that will be evaluated by Groovy. Bean BindingBean Binding in Camel defines both which methods are invoked and also how the Message is converted into the parameters of the method when it is invoked. Choosing the method to invokeThe binding of a Camel Message to a bean method call can occur in different ways, in the following order of importance:
In cases where Camel cannot choose a method to invoke, an AmbiguousMethodCallException is thrown. By default the return value is set on the outbound message body. Parameter bindingWhen a method has been chosen for invokation, Camel will bind to the parameters of the method. The following Camel-specific types are automatically bound:
So, if you declare any of these types, they will be provided by Camel. Note that Exception will bind to the caught exception of the Exchange - so it's often usable if you employ a Pojo to handle, e.g., an onException route. What is most interesting is that Camel will also try to bind the body of the Exchange to the first parameter of the method signature (albeit not of any of the types above). So if, for instance, we declare a parameter as String body, then Camel will bind the IN body to this type. Camel will also automatically convert to the type declared in the method signature. Let's review some examples: Below is a simple method with a body binding. Camel will bind the IN body to the body parameter and convert it to a String. public String doSomething(String body) In the following sample we got one of the automatically-bound types as well - for instance, a Registry that we can use to lookup beans. public String doSomething(String body, Registry registry) We can use Exchange as well: public String doSomething(String body, Exchange exchange) You can also have multiple types: public String doSomething(String body, Exchange exchange, TypeConverter converter) And imagine you use a Pojo to handle a given custom exception InvalidOrderException - we can then bind that as well: public String badOrder(String body, InvalidOrderException invalid) Notice that we can bind to it even if we use a sub type of java.lang.Exception as Camel still knows it's an exception and can bind the cause (if any exists). So what about headers and other stuff? Well now it gets a bit tricky - so we can use annotations to help us, or specify the binding in the method name option. Binding AnnotationsYou can use the Parameter Binding Annotations to customize how parameter values are created from the Message ExamplesFor example, a Bean such as: public class Bar { public String doSomething(String body) { // process the in body and return whatever you want return "Bye World"; } Or the Exchange example. Notice that the return type must be void when there is only a single parameter: public class Bar { public void doSomething(Exchange exchange) { // process the exchange exchange.getIn().setBody("Bye World"); } @HandlerYou can mark a method in your bean with the @Handler annotation to indicate that this method should be used for Bean Binding. public class Bar { @Handler public String doSomething(String body) { // process the in body and return whatever you want return "Bye World"; } Parameter binding using method optionAvailable as of Camel 2.9 Camel uses the following rules to determine if it's a parameter value in the method option
Any other value is consider to be a type declaration instead - see the next section about specifying types for overloaded methods. When invoking a Bean you can instruct Camel to invoke a specific method by providing the method name:
.bean(OrderService.class, "doSomething")
Here we tell Camel to invoke the doSomething method - Camel handles the parameters' binding. Now suppose the method has 2 parameters, and the 2nd parameter is a boolean where we want to pass in a true value: public void doSomething(String payload, boolean highPriority) { ... } This is now possible in Camel 2.9 onwards:
.bean(OrderService.class, "doSomething(*, true)")
In the example above, we defined the first parameter using the wild card symbol *, which tells Camel to bind this parameter to any type, and let Camel figure this out. The 2nd parameter has a fixed value of true. Instead of the wildcard symbol we can instruct Camel to use the message body as shown:
.bean(OrderService.class, "doSomething(${body}, true)")
The syntax of the parameters is using the Simple expression language so we have to use ${ } placeholders in the body to refer to the message body. If you want to pass in a null value, then you can explicit define this in the method option as shown below:
.to("bean:orderService?method=doSomething(null, true)")
Specifying null as a parameter value instructs Camel to force passing a null value. Besides the message body, you can pass in the message headers as a java.util.Map:
.bean(OrderService.class, "doSomethingWithHeaders(${body}, ${headers})")
You can also pass in other fixed values besides booleans. For example, you can pass in a String and an integer:
.bean(MyBean.class, "echo('World', 5)")
In the example above, we invoke the echo method with two parameters. The first has the content 'World' (without quotes), and the 2nd has the value of 5. Having the power of the Simple language allows us to bind to message headers and other values such as:
.bean(OrderService.class, "doSomething(${body}, ${header.high})")
You can also use the OGNL support of the Simple expression language. Now suppose the message body is an object which has a method named asXml. To invoke the asXml method we can do as follows:
.bean(OrderService.class, "doSomething(${body.asXml}, ${header.high})")
Instead of using .bean as shown in the examples above, you may want to use .to instead as shown:
.to("bean:orderService?method=doSomething(${body.asXml}, ${header.high})")
Using type qualifiers to select among overloaded methodsAvailable as of Camel 2.8 If you have a Bean with overloaded methods, you can now specify parameter types in the method name so Camel can match the method you intend to use. MyBean public static final class MyBean { public String hello(String name) { return "Hello " + name; } public String hello(String name, @Header("country") String country) { return "Hello " + name + " you are from " + country; } public String times(String name, @Header("times") int times) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < times; i++) { sb.append(name); } return sb.toString(); } public String times(byte[] data, @Header("times") int times) { String s = new String(data); StringBuilder sb = new StringBuilder(); for (int i = 0; i < times; i++) { sb.append(s); if (i < times - 1) { sb.append(","); } } return sb.toString(); } public String times(String name, int times, char separator) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < times; i++) { sb.append(name); if (i < times - 1) { sb.append(separator); } } return sb.toString(); } } Then the MyBean has 2 overloaded methods with the names hello and times. So if we want to use the method which has 2 parameters we can do as follows in the Camel route: Invoke 2 parameter method from("direct:start") .bean(MyBean.class, "hello(String,String)") .to("mock:result"); We can also use a * as wildcard so we can just say we want to execute the method with 2 parameters we do Invoke 2 parameter method using wildcard from("direct:start") .bean(MyBean.class, "hello(*,*)") .to("mock:result"); By default Camel will match the type name using the simple name, e.g. any leading package name will be disregarded. However if you want to match using the FQN, then specify the FQN type and Camel will leverage that. So if you have a com.foo.MyOrder and you want to match against the FQN, and not the simple name "MyOrder", then follow this example:
.bean(OrderService.class, "doSomething(com.foo.MyOrder)")
Bean InjectionWe support the injection of various resources using @EndpointInject. This can be used to inject
Parameter Binding Annotations
Annotations can be used to define an Expression or to extract various headers, properties or payloads from a Message when invoking a bean method (see Bean Integration for more detail of how to invoke bean methods) together with being useful to help disambiguate which method to invoke. If no annotations are used then Camel assumes that a single parameter is the body of the message. Camel will then use the Type Converter mechanism to convert from the expression value to the actual type of the parameter. The core annotations are as follows
The follow annotations @Headers, @OutHeaders and @Properties binds to the backing java.util.Map so you can alter the content of these maps directly, for instance using the put method to add a new entry. See the OrderService class at Exception Clause for such an example. Since Camel 2.0, you can use @Header("myHeader") and @Property("myProperty") instead of @Header(name="myHeader") and @Property(name="myProperty") as Camel 1.x does. ExampleIn this example below we have a @Consume consumer (like message driven) that consumes JMS messages from the activemq queue. We use the @Header and @Body parameter binding annotations to bind from the JMSMessage to the method parameters. public class Foo { @Consume(uri = "activemq:my.queue") public void doSomething(@Header("JMSCorrelationID") String correlationID, @Body String body) { // process the inbound message here } } In the above Camel will extract the value of Message.getJMSCorrelationID(), then using the Type Converter to adapt the value to the type of the parameter if required - it will inject the parameter value for the correlationID parameter. Then the payload of the message will be converted to a String and injected into the body parameter. You don't need to use the @Consume annotation; as you could use the Camel DSL to route to the beans method Using the DSL to invoke the bean methodHere is another example which does not use POJO Consuming annotations but instead uses the DSL to route messages to the bean method public class Foo { public void doSomething(@Header("JMSCorrelationID") String correlationID, @Body String body) { // process the inbound message here } } The routing DSL then looks like this from("activemq:someQueue"). to("bean:myBean"); Here myBean would be looked up in the Registry (such as JNDI or the Spring ApplicationContext), then the body of the message would be used to try figure out what method to call. If you want to be explicit you can use from("activemq:someQueue"). to("bean:myBean?methodName=doSomething"); And here we have a nifty example for you to show some great power in Camel. You can mix and match the annotations with the normal parameters, so we can have this example with annotations and the Exchange also:
public void doSomething(@Header("user") String user, @Body String body, Exchange exchange) {
exchange.getIn().setBody(body + "MyBean");
}
Annotation Based Expression LanguageYou can also use any of the Languages supported in Camel to bind expressions to method parameters when using Bean Integration. For example you can use any of these annotations:
Example:public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@XPath("/foo/bar/text()") String correlationID, @Body String body) { // process the inbound message here } } Advanced example using @BeanAnd an example of using the the @Bean binding annotation, where you can use a Pojo where you can do whatever java code you like: public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@Bean("myCorrelationIdGenerator") String correlationID, @Body String body) { // process the inbound message here } } And then we can have a spring bean with the id myCorrelationIdGenerator where we can compute the id. public class MyIdGenerator { private UserManager userManager; public String generate(@Header(name = "user") String user, @Body String payload) throws Exception { User user = userManager.lookupUser(user); String userId = user.getPrimaryId(); String id = userId + generateHashCodeForPayload(payload); return id; } } The Pojo MyIdGenerator has one public method that accepts two parameters. However we have also annotated this one with the @Header and @Body annotation to help Camel know what to bind here from the Message from the Exchange being processed. Of course this could be simplified a lot if you for instance just have a simple id generator. But we wanted to demonstrate that you can use the Bean Binding annotations anywhere. public class MySimpleIdGenerator { public static int generate() { // generate a unique id return 123; } } And finally we just need to remember to have our bean registered in the Spring Registry:
<bean id="myCorrelationIdGenerator" class="com.mycompany.MySimpleIdGenerator"/>
Example using GroovyIn this example we have an Exchange that has a User object stored in the in header. This User object has methods to get some user information. We want to use Groovy to inject an expression that extracts and concats the fullname of the user into the fullName parameter.
public void doSomething(@Groovy("$request.header['user'].firstName $request.header['user'].familyName) String fullName, @Body String body) {
// process the inbound message here
}
Groovy supports GStrings that is like a template where we can insert $ placeholders that will be evaluated by Groovy. @MessageDriven or @Consume
To consume a message you use either the @MessageDriven annotation or from 1.5.0 the @Consume annotation to mark a particular method of a bean as being a consumer method. The uri of the annotation defines the Camel Endpoint to consume from. e.g. lets invoke the onCheese() method with the String body of the inbound JMS message from ActiveMQ on the cheese queue; this will use the Type Converter to convert the JMS ObjectMessage or BytesMessage to a String - or just use a TextMessage from JMS public class Foo { @Consume(uri="activemq:cheese") public void onCheese(String name) { ... } } The Bean Binding is then used to convert the inbound Message to the parameter list used to invoke the method . What this does is basically create a route that looks kinda like this
from(uri).bean(theBean, "methodName");
Using context option to apply only a certain CamelContextAvailable as of Camel 2.0 You can use the context option to specify which CamelContext the consumer should only apply for. For example: @Consume(uri="activemq:cheese", context="camel-1") public void onCheese(String name) { The consumer above will only be created for the CamelContext that have the context id = camel-1. You set this id in the XML tag:
<camelContext id="camel-1" ...>
Using an explicit routeIf you want to invoke a bean method from many different endpoints or within different complex routes in different circumstances you can just use the normal routing DSL or the Spring XML configuration file. For example from(uri).beanRef("myBean", "methodName"); which will then look up in the Registry and find the bean and invoke the given bean name. (You can omit the method name and have Camel figure out the right method based on the method annotations and body type). Use the Bean endpointYou can always use the bean endpoint
from(uri).to("bean:myBean?method=methodName");
Which approach to use?Using the @MessageDriven/@Consume annotations are simpler when you are creating a simple route with a single well defined input URI. However if you require more complex routes or the same bean method needs to be invoked from many places then please use the routing DSL as shown above. There are two different ways to send messages to any Camel Endpoint from a POJO @EndpointInjectTo allow sending of messages from POJOs you can use @EndpointInject() annotation. This will inject either a ProducerTemplate or CamelTemplate so that the bean can send message exchanges. e.g. lets send a message to the foo.bar queue in ActiveMQ at some point public class Foo { @EndpointInject(uri="activemq:foo.bar") ProducerTemplate producer; public void doSomething() { if (whatever) { producer.sendBody("<hello>world!</hello>"); } } } The downside of this is that your code is now dependent on a Camel API, the ProducerTemplate. The next section describes how to remove this Hiding the Camel APIs from your code using @ProduceWe recommend Hiding Middleware APIs from your application code so the next option might be more suitable. public interface MyListener { String sayHello(String name); } public class MyBean { @Produce(uri = "activemq:foo") protected MyListener producer; public void doSomething() { // lets send a message String response = producer.sayHello("James"); } } Here Camel will automatically inject a smart client side proxy at the @Produce annotation - an instance of the MyListener instance. When we invoke methods on this interface the method call is turned into an object and using the Camel Spring Remoting mechanism it is sent to the endpoint - in this case the ActiveMQ endpoint to queue foo; then the caller blocks for a response. If you want to make asynchronous message sends then use an @InOnly annotation on the injection point. @RecipientList AnnotationAs of 1.5.0 we now support the use of @RecipientList on a bean method to easily create a dynamic Recipient List using a Java method. Simple Example using @Consume and @RecipientListpackage com.acme.foo; public class RouterBean { @Consume(uri = "activemq:foo") @RecipientList public String[] route(String body) { return new String[]{"activemq:bar", "activemq:whatnot"}; } } For example if the above bean is configured in Spring when using a <camelContext> element as follows <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://activemq.apache.org/camel/schema/spring http://activemq.apache.org/camel/schema/spring/camel-spring.xsd "> <camelContext xmlns="http://activemq.apache.org/camel/schema/spring"/> <bean id="myRecipientList" class="com.acme.foo.RouterBean"/> </beans> then a route will be created consuming from the foo queue on the ActiveMQ component which when a message is received the message will be forwarded to the endpoints defined by the result of this method call - namely the bar and whatnot queues. How it worksThe return value of the @RecipientList method is converted to either a java.util.Collection / java.util.Iterator or array of objects where each element is converted to an Endpoint or a String, or if you are only going to route to a single endpoint then just return either an Endpoint object or an object that can be converted to a String. So the following methods are all valid @RecipientList public String[] route(String body) { ... } @RecipientList public List<String> route(String body) { ... } @RecipientList public Endpoint route(String body) { ... } @RecipientList public Endpoint[] route(String body) { ... } @RecipientList public Collection<Endpoint> route(String body) { ... } @RecipientList public URI route(String body) { ... } @RecipientList public URI[] route(String body) { ... } Then for each endpoint or URI the message is forwarded a separate copy to that endpoint. You can then use whatever Java code you wish to figure out what endpoints to route to; for example you can use the Bean Binding annotations to inject parts of the message body or headers or use Expression values on the message. More Complex Example Using DSLIn this example we will use more complex Bean Binding, plus we will use a separate route to invoke the Recipient List public class RouterBean2 { @RecipientList public String route(@Header("customerID") String custID String body) { if (custID == null) return null; return "activemq:Customers.Orders." + custID; } } public class MyRouteBuilder extends RouteBuilder { protected void configure() { from("activemq:Orders.Incoming").recipientList(bean("myRouterBean", "route")); } } Notice how we are injecting some headers or expressions and using them to determine the recipients using Recipient List EIP. Using Exchange Pattern AnnotationsWhen working with POJO Producing or Spring Remoting you invoke methods which typically by default are InOut for Request Reply. That is there is an In message and an Out for the result. Typically invoking this operation will be synchronous, the caller will block until the server returns a result. Camel has flexible Exchange Pattern support - so you can also support the Event Message pattern to use InOnly for asynchronous or one way operations. These are often called 'fire and forget' like sending a JMS message but not waiting for any response. From 1.5 onwards Camel supports annotations for specifying the message exchange pattern on regular Java methods, classes or interfaces. Specifying InOnly methodsTypically the default InOut is what most folks want but you can customize to use InOnly using an annotation. public interface Foo { Object someInOutMethod(String input); String anotherInOutMethod(Cheese input); @InOnly void someInOnlyMethod(Document input); } The above code shows three methods on an interface; the first two use the default InOut mechanism but the someInOnlyMethod uses the InOnly annotation to specify it as being a oneway method call. Class level annotationsYou can also use class level annotations to default all methods in an interface to some pattern such as @InOnly public interface Foo { void someInOnlyMethod(Document input); void anotherInOnlyMethod(String input); } Annotations will also be detected on base classes or interfaces. So for example if you created a client side proxy for public class MyFoo implements Foo { ... } Then the methods inherited from Foo would be InOnly. Overloading a class level annotationYou can overload a class level annotation on specific methods. A common use case for this is if you have a class or interface with many InOnly methods but you want to just annote one or two methods as InOut @InOnly public interface Foo { void someInOnlyMethod(Document input); void anotherInOnlyMethod(String input); @InOut String someInOutMethod(String input); } In the above Foo interface the someInOutMethod will be InOut Using your own annotationsYou might want to create your own annotations to represent a group of different bits of metadata; such as combining synchrony, concurrency and transaction behaviour. So you could annotate your annotation with the @Pattern annotation to default the exchange pattern you wish to use. For example lets say we want to create our own annotation called @MyAsyncService
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
// lets add the message exchange pattern to it
@Pattern(ExchangePattern.InOnly)
// lets add some other annotations - maybe transaction behaviour?
public @interface MyAsyncService {
}
Now we can use this annotation and Camel will figure out the correct exchange pattern... public interface Foo { void someInOnlyMethod(Document input); void anotherInOnlyMethod(String input); @MyAsyncService String someInOutMethod(String input); } When writing software these days, its important to try and decouple as much middleware code from your business logic as possible. This provides a number of benefits...
For example if you want to implement some kind of message passing, remoting, reliable load balancing or asynchronous processing in your application we recommend you use Camel annotations to bind your services and business logic to Camel Components which means you can then easily switch between things like
How to decouple from middleware APIsThe best approach when using remoting is to use Spring Remoting which can then use any messaging or remoting technology under the covers. When using Camel's implementation you can then use any of the Camel Components along with any of the Enterprise Integration Patterns. Another approach is to bind Java beans to Camel endpoints via the Bean Integration. For example using POJO Consuming and POJO Producing you can avoid using any Camel APIs to decouple your code both from middleware APIs and Camel APIs! VisualisationCamel supports the visualisation of your Enterprise Integration Patterns using the GraphViz DOT files which can either be rendered directly via a suitable GraphViz tool or turned into HTML, PNG or SVG files via the Camel Maven Plugin. Here is a typical example of the kind of thing we can generate
If you click on the actual generated htmlyou will see that you can navigate from an EIP node to its pattern page, along with getting hover-over tool tips ec. How to generateSee Camel Dot Maven Goal or the other maven goals Camel Maven Plugin For OS X usersIf you are using OS X then you can open the DOT file using graphviz which will then automatically re-render if it changes, so you end up with a real time graphical representation of the topic and queue hierarchies! Also if you want to edit the layout a little before adding it to a wiki to distribute to your team, open the DOT file with OmniGraffle then just edit away Business Activity MonitoringThe Camel BAM module provides a Business Activity Monitoring (BAM) framework for testing business processes across multiple message exchanges on different Endpoint instances. Consider, for example, a simple system in which you submit Purchase Orders into system A and then receive Invoices from system B. You might want to test that, for a given Purchase Order, you receive a matching Invoice from system B within a specific time period. How Camel BAM WorksCamel BAM uses a Correlation Identifier on an input message to determine the Process Instance to which it belongs. The process instance is an entity bean which can maintain state for each Activity (where an activity typically maps to a single endpoint - such as the submission of Purchase Orders or the receipt of Invoices). You can then add rules to be triggered when a message is received on any activity - such as to set time expectations or perform real time reconciliation of values across activities. Simple ExampleThe following example shows how to perform some time based rules on a simple business process of 2 activities - A and B - which correspond with Purchase Orders and Invoices in the example above. If you would like to experiment with this scenario, you may edit this Test Case, which defines the activities and rules, and then tests that they work. return new ProcessBuilder(jpaTemplate, transactionTemplate) { public void configure() throws Exception { // let's define some activities, correlating on an XPath on the message bodies ActivityBuilder a = activity("seda:a").name("a") .correlate(xpath("/hello/@id")); ActivityBuilder b = activity("seda:b").name("b") .correlate(xpath("/hello/@id")); // now let's add some rules b.starts().after(a.completes()) .expectWithin(seconds(1)) .errorIfOver(seconds(errorTimeout)).to("mock:overdue"); } }; As you can see in the above example, we first define two activities, and then rules to specify when we expect them to complete for a process instance and when an error condition should be raised.p. The ProcessBuilder is a RouteBuilder and can be added to any CamelContext. Complete ExampleFor a complete example please see the BAM Example, which is part of the standard Camel Examples Use CasesIn the world of finance, a common requirement is tracking trades. Often a trader will submit a Front Office Trade which then flows through the Middle Office and Back Office through various systems to settle the trade so that money is exchanged. You may wish to test that the front and back office trades match up within a certain time period; if they don't match or a back office trade does not arrive within a required amount of time, you might signal an alarm. Extract Transform Load (ETL)The ETL (Extract, Transform, Load) is a mechanism for loading data into systems or databases using some kind of Data Format from a variety of sources; often files then using Pipes and Filters, Message Translator and possible other Enterprise Integration Patterns. So you could query data from various Camel Components such as File, HTTP or JPA, perform multiple patterns such as Splitter or Message Translator then send the messages to some other Component. To show how this all fits together, try the ETL Example Mock ComponentTesting of distributed and asynchronous processing is notoriously difficult. The Mock, Test and DataSet endpoints work great with the Camel Testing Framework to simplify your unit and integration testing using Enterprise Integration Patterns and Camel's large range of Components together with the powerful Bean Integration. The Mock component provides a powerful declarative testing mechanism, which is similar to jMock in that it allows declarative expectations to be created on any Mock endpoint before a test begins. Then the test is run, which typically fires messages to one or more endpoints, and finally the expectations can be asserted in a test case to ensure the system worked as expected. This allows you to test various things like:
Note that there is also the Test endpoint which is a Mock endpoint, but which uses a second endpoint to provide the list of expected message bodies and automatically sets up the Mock endpoint assertions. In other words, it's a Mock endpoint that automatically sets up its assertions from some sample messages in a File or database, for example.
URI formatmock:someName[?options] Where someName can be any string that uniquely identifies the endpoint. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Simple ExampleHere's a simple example of Mock endpoint in use. First, the endpoint is resolved on the context. Then we set an expectation, and then, after the test has run, we assert that our expectations have been met. MockEndpoint resultEndpoint = context.resolveEndpoint("mock:foo", MockEndpoint.class); resultEndpoint.expectedMessageCount(2); // send some messages ... // now lets assert that the mock:foo endpoint received 2 messages resultEndpoint.assertIsSatisfied(); You typically always call the assertIsSatisfied() method to test that the expectations were met after running a test. Camel will by default wait 10 seconds when the assertIsSatisfied() is invoked. This can be configured by setting the setResultWaitTime(millis) method. When the assertion is satisfied then Camel will stop waiting and continue from the assertIsSatisfied method. That means if a new message arrives on the mock endpoint, just a bit later, that arrival will not affect the outcome of the assertion. Suppose you do want to test that no new messages arrives after a period thereafter, then you can do that by setting the setAssertPeriod method. Using assertPeriodAvailable as of Camel 2.7 MockEndpoint resultEndpoint = context.resolveEndpoint("mock:foo", MockEndpoint.class); resultEndpoint.setAssertPeriod(5000); resultEndpoint.expectedMessageCount(2); // send some messages ... // now lets assert that the mock:foo endpoint received 2 messages resultEndpoint.assertIsSatisfied(); Setting expectationsYou can see from the javadoc of MockEndpoint the various helper methods you can use to set expectations. The main methods are as follows:
Here's another example: resultEndpoint.expectedBodiesReceived("firstMessageBody", "secondMessageBody", "thirdMessageBody"); Adding expectations to specific messagesIn addition, you can use the message(int messageIndex) method to add assertions about a specific message that is received. For example, to add expectations of the headers or body of the first message (using zero-based indexing like java.util.List), you can use the following code: resultEndpoint.message(0).header("foo").isEqualTo("bar"); There are some examples of the Mock endpoint in use in the camel-core processor tests. Mocking existing endpointsAvailable as of Camel 2.7 Camel now allows you to automatic mock existing endpoints in your Camel routes.
Suppose you have the given route below: Route @Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { from("direct:start").to("direct:foo").to("log:foo").to("mock:result"); from("direct:foo").transform(constant("Bye World")); } }; } You can then use the adviceWith feature in Camel to mock all the endpoints in a given route from your unit test, as shown below: adviceWith mocking all endpoints public void testAdvisedMockEndpoints() throws Exception { // advice the first route using the inlined AdviceWith route builder // which has extended capabilities than the regular route builder context.getRouteDefinitions().get(0).adviceWith(context, new AdviceWithRouteBuilder() { @Override public void configure() throws Exception { // mock all endpoints mockEndpoints(); } }); getMockEndpoint("mock:direct:start").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:direct:foo").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:log:foo").expectedBodiesReceived("Bye World"); getMockEndpoint("mock:result").expectedBodiesReceived("Bye World"); template.sendBody("direct:start", "Hello World"); assertMockEndpointsSatisfied(); // additional test to ensure correct endpoints in registry assertNotNull(context.hasEndpoint("direct:start")); assertNotNull(context.hasEndpoint("direct:foo")); assertNotNull(context.hasEndpoint("log:foo")); assertNotNull(context.hasEndpoint("mock:result")); // all the endpoints was mocked assertNotNull(context.hasEndpoint("mock:direct:start")); assertNotNull(context.hasEndpoint("mock:direct:foo")); assertNotNull(context.hasEndpoint("mock:log:foo")); } Notice that the mock endpoints is given the uri mock:<endpoint>, for example mock:direct:foo. Camel logs at INFO level the endpoints being mocked:
INFO Adviced endpoint [direct://foo] with mock endpoint [mock:direct:foo]
Its also possible to only mock certain endpoints using a pattern. For example to mock all log endpoints you do as shown: adviceWith mocking only log endpoints using a pattern public void testAdvisedMockEndpointsWithPattern() throws Exception { // advice the first route using the inlined AdviceWith route builder // which has extended capabilities than the regular route builder context.getRouteDefinitions().get(0).adviceWith(context, new AdviceWithRouteBuilder() { @Override public void configure() throws Exception { // mock only log endpoints mockEndpoints("log*"); } }); // now we can refer to log:foo as a mock and set our expectations getMockEndpoint("mock:log:foo").expectedBodiesReceived("Bye World"); getMockEndpoint("mock:result").expectedBodiesReceived("Bye World"); template.sendBody("direct:start", "Hello World"); assertMockEndpointsSatisfied(); // additional test to ensure correct endpoints in registry assertNotNull(context.hasEndpoint("direct:start")); assertNotNull(context.hasEndpoint("direct:foo")); assertNotNull(context.hasEndpoint("log:foo")); assertNotNull(context.hasEndpoint("mock:result")); // only the log:foo endpoint was mocked assertNotNull(context.hasEndpoint("mock:log:foo")); assertNull(context.hasEndpoint("mock:direct:start")); assertNull(context.hasEndpoint("mock:direct:foo")); } The pattern supported can be a wildcard or a regular expression. See more details about this at Intercept as its the same matching function used by Camel.
Mocking existing endpoints using the camel-test componentInstead of using the adviceWith to instruct Camel to mock endpoints, you can easily enable this behavior when using the camel-test Test Kit. isMockEndpoints using camel-test kit public class IsMockEndpointsJUnit4Test extends CamelTestSupport { @Override public String isMockEndpoints() { // override this method and return the pattern for which endpoints to mock. // use * to indicate all return "*"; } @Test public void testMockAllEndpoints() throws Exception { // notice we have automatic mocked all endpoints and the name of the endpoints is "mock:uri" getMockEndpoint("mock:direct:start").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:direct:foo").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:log:foo").expectedBodiesReceived("Bye World"); getMockEndpoint("mock:result").expectedBodiesReceived("Bye World"); template.sendBody("direct:start", "Hello World"); assertMockEndpointsSatisfied(); // additional test to ensure correct endpoints in registry assertNotNull(context.hasEndpoint("direct:start")); assertNotNull(context.hasEndpoint("direct:foo")); assertNotNull(context.hasEndpoint("log:foo")); assertNotNull(context.hasEndpoint("mock:result")); // all the endpoints was mocked assertNotNull(context.hasEndpoint("mock:direct:start")); assertNotNull(context.hasEndpoint("mock:direct:foo")); assertNotNull(context.hasEndpoint("mock:log:foo")); } @Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { from("direct:start").to("direct:foo").to("log:foo").to("mock:result"); from("direct:foo").transform(constant("Bye World")); } }; } } Mocking existing endpoints with XML DSLIf you do not use the camel-test component for unit testing (as shown above) you can use a different approach when using XML files for routes. Suppose we have the route in the camel-route.xml file: camel-route.xml <!-- this camel route is in the camel-route.xml file --> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <to uri="direct:foo"/> <to uri="log:foo"/> <to uri="mock:result"/> </route> <route> <from uri="direct:foo"/> <transform> <constant>Bye World</constant> </transform> </route> </camelContext> Then we create a new XML file as follows, where we include the camel-route.xml file and define a spring bean with the class org.apache.camel.impl.InterceptSendToMockEndpointStrategy which tells Camel to mock all endpoints: test-camel-route.xml <!-- the Camel route is defined in another XML file --> <import resource="camel-route.xml"/> <!-- bean which enables mocking all endpoints --> <bean id="mockAllEndpoints" class="org.apache.camel.impl.InterceptSendToMockEndpointStrategy"/> Then in your unit test you load the new XML file (test-camel-route.xml) instead of camel-route.xml. To only mock all Log endpoints you can define the pattern in the constructor for the bean: <bean id="mockAllEndpoints" class="org.apache.camel.impl.InterceptSendToMockEndpointStrategy"> <constructor-arg index="0" value="log*"/> </bean> Testing with arrival timesAvailable as of Camel 2.7 The Mock endpoint stores the arrival time of the message as a property on the Exchange. Date time = exchange.getProperty(Exchange.RECEIVED_TIMESTAMP, Date.class); You can use this information to know when the message arrived on the mock. But it also provides foundation to know the time interval between the previous and next message arrived on the mock. You can use this to set expectations using the arrives DSL on the Mock endpoint. For example to say that the first message should arrive between 0-2 seconds before the next you can do: mock.message(0).arrives().noLaterThan(2).seconds().beforeNext(); You can also define this as that 2nd message (0 index based) should arrive no later than 0-2 seconds after the previous: mock.message(1).arrives().noLaterThan(2).seconds().afterPrevious(); You can also use between to set a lower bound. For example suppose that it should be between 1-4 seconds: mock.message(1).arrives().between(1, 4).seconds().afterPrevious(); You can also set the expectation on all messages, for example to say that the gap between them should be at most 1 second: mock.allMessages().arrives().noLaterThan(1).seconds().beforeNext();
See AlsoTestingTesting is a crucial activity in any piece of software development or integration. Typically Camel Riders use various different technologies wired together in a variety of patterns with different expression languages together with different forms of Bean Integration and Dependency Injection so its very easy for things to go wrong! Camel is a Java library so you can easily wire up tests in whatever unit testing framework you use (JUnit 3.x, 4.x or TestNG). However the Camel project has tried to make the testing of Camel as easy and powerful as possible so we have introduced the following features. Testing mechanismsThe following mechanisms are supported
In all approaches the test classes look pretty much the same in that they all reuse the Camel binding and injection annotations. Camel Test ExampleHere is the Camel Test example. public class FilterTest extends CamelTestSupport { @EndpointInject(uri = "mock:result") protected MockEndpoint resultEndpoint; @Produce(uri = "direct:start") protected ProducerTemplate template; @Test public void testSendMatchingMessage() throws Exception { String expectedBody = "<matched/>"; resultEndpoint.expectedBodiesReceived(expectedBody); template.sendBodyAndHeader(expectedBody, "foo", "bar"); resultEndpoint.assertIsSatisfied(); } @Test public void testSendNotMatchingMessage() throws Exception { resultEndpoint.expectedMessageCount(0); template.sendBodyAndHeader("<notMatched/>", "foo", "notMatchedHeaderValue"); resultEndpoint.assertIsSatisfied(); } @Override protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from("direct:start").filter(header("foo").isEqualTo("bar")).to("mock:result"); } }; } } Notice how it derives from the Camel helper class CamelTestSupport but has no Spring or Guice dependency injection configuration but instead overrides the createRouteBuilder() method. Spring Test with XML Config ExampleHere is the Spring Testing example using XML Config. @ContextConfiguration public class FilterTest extends AbstractJUnit38SpringContextTests { @EndpointInject(uri = "mock:result") protected MockEndpoint resultEndpoint; @Produce(uri = "direct:start") protected ProducerTemplate template; @DirtiesContext public void testSendMatchingMessage() throws Exception { String expectedBody = "<matched/>"; resultEndpoint.expectedBodiesReceived(expectedBody); template.sendBodyAndHeader(expectedBody, "foo", "bar"); resultEndpoint.assertIsSatisfied(); } @DirtiesContext public void testSendNotMatchingMessage() throws Exception { resultEndpoint.expectedMessageCount(0); template.sendBodyAndHeader("<notMatched/>", "foo", "notMatchedHeaderValue"); resultEndpoint.assertIsSatisfied(); } } Notice that we use @DirtiesContext on the test methods to force Spring Testing to automatically reload the CamelContext after each test method - this ensures that the tests don't clash with each other (e.g. one test method sending to an endpoint that is then reused in another test method). Also notice the use of @ContextConfiguration to indicate that by default we should look for the FilterTest-context.xml on the classpath to configure the test case which looks like this <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd "> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <filter> <xpath>$foo = 'bar'</xpath> <to uri="mock:result"/> </filter> </route> </camelContext> </beans> Spring Test with Java Config ExampleHere is the Spring Testing example using Java Config. For more information see Spring Java Config. @ContextConfiguration(
locations = "org.apache.camel.spring.javaconfig.patterns.FilterTest$ContextConfig",
loader = JavaConfigContextLoader.class)
public class FilterTest extends AbstractJUnit4SpringContextTests {
@EndpointInject(uri = "mock:result")
protected MockEndpoint resultEndpoint;
@Produce(uri = "direct:start")
protected ProducerTemplate template;
@DirtiesContext
@Test
public void testSendMatchingMessage() throws Exception {
String expectedBody = "<matched/>";
resultEndpoint.expectedBodiesReceived(expectedBody);
template.sendBodyAndHeader(expectedBody, "foo", "bar");
resultEndpoint.assertIsSatisfied();
}
@DirtiesContext
@Test
public void testSendNotMatchingMessage() throws Exception {
resultEndpoint.expectedMessageCount(0);
template.sendBodyAndHeader("<notMatched/>", "foo", "notMatchedHeaderValue");
resultEndpoint.assertIsSatisfied();
}
@Configuration
public static class ContextConfig extends SingleRouteCamelConfiguration {
@Bean
public RouteBuilder route() {
return new RouteBuilder() {
public void configure() {
from("direct:start").filter(header("foo").isEqualTo("bar")).to("mock:result");
}
};
}
}
}
This is similar to the XML Config example above except that there is no XML file and instead the nested ContextConfig class does all of the configuration; so your entire test case is contained in a single Java class. We currently have to reference by class name this class in the @ContextConfiguration which is a bit ugly. Please vote for SJC-238 to address this and make Spring Test work more cleanly with Spring JavaConfig. Its totally optional but for the ContextConfig implementation we derive from SingleRouteCamelConfiguration which is a helper Spring Java Config class which will configure the CamelContext for us and then register the RouteBuilder we create. Blueprint TestHere is the Blueprint Testing example using XML Config. // to use camel-test-blueprint, then extend the CamelBlueprintTestSupport class, // and add your unit tests methods as shown below. public class DebugBlueprintTest extends CamelBlueprintTestSupport { // override this method, and return the location of our Blueprint XML file to be used for testing @Override protected String getBlueprintDescriptor() { return "org/apache/camel/test/blueprint/camelContext.xml"; } // here we have regular Junit @Test method @Test public void testRoute() throws Exception { // set mock expectations getMockEndpoint("mock:a").expectedMessageCount(1); // send a message template.sendBody("direct:start", "World"); // assert mocks assertMockEndpointsSatisfied(); } } Also notice the use of getBlueprintDescriptors to indicate that by default we should look for the camelContext.xml in the package to configure the test case which looks like this <blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd"> <camelContext xmlns="http://camel.apache.org/schema/blueprint"> <route> <from uri="direct:start"/> <transform> <simple>Hello ${body}</simple> </transform> <to uri="mock:a"/> </route> </camelContext> </blueprint> Testing endpointsCamel provides a number of endpoints which can make testing easier.
The main endpoint is the Mock endpoint which allows expectations to be added to different endpoints; you can then run your tests and assert that your expectations are met at the end. Stubbing out physical transport technologiesIf you wish to test out a route but want to avoid actually using a real physical transport (for example to unit test a transformation route rather than performing a full integration test) then the following endpoints can be useful.
Testing existing routesCamel provides some features to aid during testing of existing routes where you cannot or will not use Mock etc. For example you may have a production ready route which you want to test with some 3rd party API which sends messages into this route.
Camel TestAs a simple alternative to using Spring Testing or Guice the camel-test module was introduced into the Camel 2.0 trunk so you can perform powerful Testing of your Enterprise Integration Patterns easily.
Adding to your pom.xmlTo get started using Camel Test you will need to add an entry to your pom.xml JUnit<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-test</artifactId> <version>${camel-version}</version> <scope>test</scope> </dependency> TestNGAvailable as of Camel 2.8 <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-testng</artifactId> <version>${camel-version}</version> <scope>test</scope> </dependency> You might also want to add slf4j and log4j to ensure nice logging messages (and maybe adding a log4j.properties file into your src/test/resources directory). <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <scope>test</scope> </dependency> Writing your testYou firstly need to derive from the class CamelTestSupport and typically you will need to override the createRouteBuilder() method to create routes to be tested. Here is an example. public class FilterTest extends CamelTestSupport { @EndpointInject(uri = "mock:result") protected MockEndpoint resultEndpoint; @Produce(uri = "direct:start") protected ProducerTemplate template; @Test public void testSendMatchingMessage() throws Exception { String expectedBody = "<matched/>"; resultEndpoint.expectedBodiesReceived(expectedBody); template.sendBodyAndHeader(expectedBody, "foo", "bar"); resultEndpoint.assertIsSatisfied(); } @Test public void testSendNotMatchingMessage() throws Exception { resultEndpoint.expectedMessageCount(0); template.sendBodyAndHeader("<notMatched/>", "foo", "notMatchedHeaderValue"); resultEndpoint.assertIsSatisfied(); } @Override protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from("direct:start").filter(header("foo").isEqualTo("bar")).to("mock:result"); } }; } } Notice how you can use the various Camel binding and injection annotations to inject individual Endpoint objects - particularly the Mock endpoints which are very useful for Testing. Also you can inject producer objects such as ProducerTemplate or some application code interface for sending messages or invoking services. JNDICamel uses a Registry to allow you to configure Component or Endpoint instances or Beans used in your routes. If you are not using Spring or OSGi then JNDI is used as the default registry implementation. So you will also need to create a jndi.properties file in your src/test/resources directory so that there is a default registry available to initialise the CamelContext. Here is an example jndi.properties file java.naming.factory.initial = org.apache.camel.util.jndi.CamelInitialContextFactory Dynamically assigning portsAvailable as of Camel 2.7 Tests that use port numbers will fail if that port is already on use. AvailablePortFinder provides methods for finding unused port numbers at runtime. // Get the next available port number starting from the default starting port of 1024 int port1 = AvailablePortFinder.getNextAvailable(); /* * Get another port. Note that just getting a port number does not reserve it so * we look starting one past the last port number we got. */ int port2 = AvailablePortFinder.getNextAvailable(port1 + 1); Setup CamelContext once per class, or per every test methodAvailable as of Camel 2.8 The Camel Test kit will by default setup and shutdown CamelContext per every test method in your test class. So for example if you have 3 test methods, then CamelContext is started and shutdown after each test, that is 3 times.
You may want to do this once, to share the CamelContext between test methods, to speedup unit testing. This requires to use JUnit 4! In your unit test method you have to extend the org.apache.camel.test.junit4.CamelTestSupport or the org.apache.camel.test.junit4.CamelSpringTestSupport test class and override the isCreateCamelContextPerClass method and return true as shown in the following example: Setup CamelContext once per class public class FilterCreateCamelContextPerClassTest extends CamelTestSupport { @Override public boolean isCreateCamelContextPerClass() { // we override this method and return true, to tell Camel test-kit that // it should only create CamelContext once (per class), so we will // re-use the CamelContext between each test method in this class return true; } @Test public void testSendMatchingMessage() throws Exception { String expectedBody = "<matched/>"; getMockEndpoint("mock:result").expectedBodiesReceived(expectedBody); template.sendBodyAndHeader("direct:start", expectedBody, "foo", "bar"); assertMockEndpointsSatisfied(); } @Test public void testSendNotMatchingMessage() throws Exception { getMockEndpoint("mock:result").expectedMessageCount(0); template.sendBodyAndHeader("direct:start", "<notMatched/>", "foo", "notMatchedHeaderValue"); assertMockEndpointsSatisfied(); } @Override protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from("direct:start").filter(header("foo").isEqualTo("bar")).to("mock:result"); } }; } } See AlsoSpring TestingTesting is a crucial part of any development or integration work. The Spring Framework offers a number of features that makes it easy to test while using Spring for Inversion of Control which works with JUnit 3.x, JUnit 4.x or TestNG. We can reuse Spring for IoC and the Camel Mock and Test endpoints to create sophisticated integration tests that are easy to run and debug inside your IDE. For example here is a simple unit test import org.apache.camel.CamelContext; import org.apache.camel.component.mock.MockEndpoint; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests; @ContextConfiguration public class MyCamelTest extends AbstractJUnit38SpringContextTests { @Autowired protected CamelContext camelContext; public void testMocksAreValid() throws Exception { MockEndpoint.assertIsSatisfied(camelContext); } } This test will load a Spring XML configuration file called MyCamelTest-context.xml from the classpath in the same package structure as the MyCamelTest class and initialize it along with any Camel routes we define inside it, then inject the CamelContext instance into our test case. For instance, like this maven folder layout: src/main/java/com/mycompany/MyCamelTest.class src/main/resources/com/mycompany/MyCamelTest-context.xml Spring Test with Java Config ExampleYou can completely avoid using an XML configuration file by using Spring Java Config. Here is an example using Java Config. @ContextConfiguration(
locations = "org.apache.camel.spring.javaconfig.patterns.FilterTest$ContextConfig",
loader = JavaConfigContextLoader.class)
public class FilterTest extends AbstractJUnit4SpringContextTests {
@EndpointInject(uri = "mock:result")
protected MockEndpoint resultEndpoint;
@Produce(uri = "direct:start")
protected ProducerTemplate template;
@DirtiesContext
@Test
public void testSendMatchingMessage() throws Exception {
String expectedBody = "<matched/>";
resultEndpoint.expectedBodiesReceived(expectedBody);
template.sendBodyAndHeader(expectedBody, "foo", "bar");
resultEndpoint.assertIsSatisfied();
}
@DirtiesContext
@Test
public void testSendNotMatchingMessage() throws Exception {
resultEndpoint.expectedMessageCount(0);
template.sendBodyAndHeader("<notMatched/>", "foo", "notMatchedHeaderValue");
resultEndpoint.assertIsSatisfied();
}
@Configuration
public static class ContextConfig extends SingleRouteCamelConfiguration {
@Bean
public RouteBuilder route() {
return new RouteBuilder() {
public void configure() {
from("direct:start").filter(header("foo").isEqualTo("bar")).to("mock:result");
}
};
}
}
}
This is similar to the XML Config example above except that there is no XML file and instead the nested ContextConfig class does all of the configuration; so your entire test case is contained in a single Java class. We currently have to reference by class name this class in the @ContextConfiguration which is a bit ugly. Please vote for SJC-238 to address this and make Spring Test work more cleanly with Spring JavaConfig. Adding more Mock expectationsIf you wish to programmatically add any new assertions to your test you can easily do so with the following. Notice how we use @EndpointInject to inject a Camel endpoint into our code then the Mock API to add an expectation on a specific message. @ContextConfiguration public class MyCamelTest extends AbstractJUnit38SpringContextTests { @Autowired protected CamelContext camelContext; @EndpointInject(uri = "mock:foo") protected MockEndpoint foo; public void testMocksAreValid() throws Exception { // lets add more expectations foo.message(0).header("bar").isEqualTo("ABC"); MockEndpoint.assertIsSatisfied(camelContext); } } Further processing the received messagesSometimes once a Mock endpoint has received some messages you want to then process them further to add further assertions that your test case worked as you expect. So you can then process the received message exchanges if you like... @ContextConfiguration public class MyCamelTest extends AbstractJUnit38SpringContextTests { @Autowired protected CamelContext camelContext; @EndpointInject(uri = "mock:foo") protected MockEndpoint foo; public void testMocksAreValid() throws Exception { // lets add more expectations... MockEndpoint.assertIsSatisfied(camelContext); // now lets do some further assertions List<Exchange> list = foo.getReceivedExchanges(); for (Exchange exchange : list) { Message in = exchange.getIn(); ... } } } Sending and receiving messagesIt might be that the Enterprise Integration Patterns you have defined in either Spring XML or using the Java DSL do all of the sending and receiving and you might just work with the Mock endpoints as described above. However sometimes in a test case its useful to explicitly send or receive messages directly. To send or receive messages you should use the Bean Integration mechanism. For example to send messages inject a ProducerTemplate using the @EndpointInject annotation then call the various send methods on this object to send a message to an endpoint. To consume messages use the @MessageDriven annotation on a method to have the method invoked when a message is received. public class Foo { @EndpointInject(uri="activemq:foo.bar") ProducerTemplate producer; public void doSomething() { // lets send a message! producer.sendBody("<hello>world!</hello>"); } // lets consume messages from the 'cheese' queue @MessageDriven(uri="activemq:cheese") public void onCheese(String name) { ... } } See Also
Camel GuiceAs of 1.5 we now have support for Google Guice as a dependency injection framework. To use it just be dependent on camel-guice.jar which also depends on the following jars. Dependency Injecting Camel with GuiceThe GuiceCamelContext is designed to work nicely inside Guice. You then need to bind it using some Guice Module. The camel-guice library comes with a number of reusable Guice Modules you can use if you wish - or you can bind the GuiceCamelContext yourself in your own module.
So you can specify the exact RouteBuilder instances you want Injector injector = Guice.createInjector(new CamelModuleWithRouteTypes(MyRouteBuilder.class, AnotherRouteBuilder.class)); // if required you can lookup the CamelContext CamelContext camelContext = injector.getInstance(CamelContext.class); Or inject them all Injector injector = Guice.createInjector(new CamelModuleWithRouteTypes()); // if required you can lookup the CamelContext CamelContext camelContext = injector.getInstance(CamelContext.class); You can then use Guice in the usual way to inject the route instances or any other dependent objects. Bootstrapping with JNDIA common pattern used in J2EE is to bootstrap your application or root objects by looking them up in JNDI. This has long been the approach when working with JMS for example - looking up the JMS ConnectionFactory in JNDI for example. You can follow a similar pattern with Guice using the GuiceyFruit JNDI Provider which lets you bootstrap Guice from a jndi.properties file which can include the Guice Modules to create along with environment specific properties you can inject into your modules and objects. If the jndi.properties is conflict with other component, you can specify the jndi properties file name in the Guice Main with option -j or -jndiProperties with the properties file location to let Guice Main to load right jndi properties file. Configuring Component, Endpoint or RouteBuilder instancesYou can use Guice to dependency inject whatever objects you need to create, be it an Endpoint, Component, RouteBuilder or arbitrary bean used within a route. The easiest way to do this is to create your own Guice Module class which extends one of the above module classes and add a provider method for each object you wish to create. A provider method is annotated with @Provides as follows public class MyModule extends CamelModuleWithMatchingRoutes { @Provides @JndiBind("jms") JmsComponent jms(@Named("activemq.brokerURL") String brokerUrl) { return JmsComponent.jmsComponent(new ActiveMQConnectionFactory(brokerUrl)); } } You can optionally annotate the method with @JndiBind to bind the object to JNDI at some name if the object is a component, endpoint or bean you wish to refer to by name in your routes. You can inject any environment specific properties (such as URLs, machine names, usernames/passwords and so forth) from the jndi.properties file easily using the @Named annotation as shown above. This allows most of your configuration to be in Java code which is typesafe and easily refactorable - then leaving some properties to be environment specific (the jndi.properties file) which you can then change based on development, testing, production etc. Creating multiple RouteBuilder instances per typeIt is sometimes useful to create multiple instances of a particular RouteBuilder with different configurations. To do this just create multiple provider methods for each configuration; or create a single provider method that returns a collection of RouteBuilder instances. For example import org.apache.camel.guice.CamelModuleWithMatchingRoutes; import com.google.common.collect.Lists; public class MyModule extends CamelModuleWithMatchingRoutes { @Provides @JndiBind("foo") Collection<RouteBuilder> foo(@Named("fooUrl") String fooUrl) { return Lists.newArrayList(new MyRouteBuilder(fooUrl), new MyRouteBuilder("activemq:CheeseQueue")); } } See Also
TemplatingWhen you are testing distributed systems its a very common requirement to have to stub out certain external systems with some stub so that you can test other parts of the system until a specific system is available or written etc. A great way to do this is using some kind of Template system to generate responses to requests generating a dynamic message using a mostly-static body. There are a number of templating components included in the Camel distribution you could use or the following external Camel components ExampleHere's a simple example showing how we can respond to InOut requests on the My.Queue queue on ActiveMQ with a template generated response. The reply would be sent back to the JMSReplyTo Destination. from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"); If you want to use InOnly and consume the message and send it to another destination you could use from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"). to("activemq:Another.Queue"); See Also
DatabaseCamel can work with databases in a number of different ways. This document tries to outline the most common approaches. Database endpointsCamel provides a number of different endpoints for working with databases
Database pattern implementationsVarious patterns can work with databases as follows
Parallel Processing and OrderingIt is a common requirement to want to use parallel processing of messages for throughput and load balancing, while at the same time process certain kinds of messages in order. How to achieve parallel processingYou can send messages to a number of Camel Components to achieve parallel processing and load balancing such as
When processing messages concurrently, you should consider ordering and concurrency issues. These are described below Concurrency issuesNote that there is no concurrency or locking issue when using ActiveMQ, JMS or SEDA by design; they are designed for highly concurrent use. However there are possible concurrency issues in the Processor of the messages i.e. what the processor does with the message? For example if a processor of a message transfers money from one account to another account; you probably want to use a database with pessimistic locking to ensure that operation takes place atomically. Ordering issuesAs soon as you send multiple messages to different threads or processes you will end up with an unknown ordering across the entire message stream as each thread is going to process messages concurrently. For many use cases the order of messages is not too important. However for some applications this can be crucial. e.g. if a customer submits a purchase order version 1, then amends it and sends version 2; you don't want to process the first version last (so that you loose the update). Your Processor might be clever enough to ignore old messages. If not you need to preserve order. RecommendationsThis topic is large and diverse with lots of different requirements; but from a high level here are our recommendations on parallel processing, ordering and concurrency
A good rule of thumb to help reduce ordering problems is to make sure each single can be processed as an atomic unit in parallel (either without concurrency issues or using say, database locking); or if it can't, use a Message Group to relate the messages together which need to be processed in order by a single thread. Using Message Groups with CamelTo use a Message Group with Camel you just need to add a header to the output JMS message based on some kind of Correlation Identifier to correlate messages which should be processed in order by a single thread - so that things which don't correlate together can be processed concurrently. For example the following code shows how to create a message group using an XPath expression taking an invoice's product code as the Correlation Identifier from("activemq:a").setHeader("JMSXGroupID", xpath("/invoice/productCode")).to("activemq:b"); You can of course use the Xml Configuration if you prefer Asynchronous ProcessingOverview
Camel supports a more complex asynchronous processing model. The asynchronous processors implement the AsyncProcessor interface which is derived from the more synchronous Processor interface. There are advantages and disadvantages when using asynchronous processing when compared to using the standard synchronous processing model. Advantages:
Disadvantages:
When to UseWe recommend that processors and components be implemented the more simple synchronous APIs unless you identify a performance of scalability requirement that dictates otherwise. A Processor whose process() method blocks for a long time would be good candidates for being converted into an asynchronous processor. Interface Detailspublic interface AsyncProcessor extends Processor { boolean process(Exchange exchange, AsyncCallback callback); } The AsyncProcessor defines a single process() method which is very similar to it's synchronous Processor.process() brethren. Here are the differences:
Implementing Processors that Use the AsyncProcessor APIAll processors, even synchronous processors that do not implement the AsyncProcessor interface, can be coerced to implement the AsyncProcessor interface. This is usually done when you are implementing a Camel component consumer that supports asynchronous completion of the exchanges that it is pushing through the Camel routes. Consumers are provided a Processor object when created. All Processor object can be coerced to a AsyncProcessor using the following API: Processor processor = ... AsyncProcessor asyncProcessor = AsyncProcessorTypeConverter.convert(processor); For a route to be fully asynchronous and reap the benefits to lower Thread usage, it must start with the consumer implementation making use of the asynchronous processing API. If it called the synchronous process() method instead, the consumer's thread would be forced to be blocked and in use for the duration that it takes to process the exchange. It is important to take note that just because you call the asynchronous API, it does not mean that the processing will take place asynchronously. It only allows the possibility that it can be done without tying up the caller's thread. If the processing happens asynchronously is dependent on the configuration of the Camel route. Normally, the the process call is passed in an inline inner AsyncCallback class instance which can reference the exchange object that was declared final. This allows it to finish up any post processing that is needed when the called processor is done processing the exchange. See below for an example. final Exchange exchange = ... AsyncProcessor asyncProcessor = ... asyncProcessor.process(exchange, new AsyncCallback() { public void done(boolean sync) { if (exchange.isFailed()) { ... // do failure processing.. perhaps rollback etc. } else { ... // processing completed successfully, finish up // perhaps commit etc. } } }); Asynchronous Route Sequence ScenariosNow that we have understood the interface contract of the AsyncProcessor, and have seen how to make use of it when calling processors, lets looks a what the thread model/sequence scenarios will look like for some sample routes. The Jetty component's consumers support async processing by using continuations. Suffice to say it can take a http request and pass it to a camel route for async processing. If the processing is indeed async, it uses Jetty continuation so that the http request is 'parked' and the thread is released. Once the camel route finishes processing the request, the jetty component uses the AsyncCallback to tell Jetty to 'un-park' the request. Jetty un-parks the request, the http response returned using the result of the exchange processing. Notice that the jetty continuations feature is only used "If the processing is indeed async". This is why AsyncProcessor.process() implementations MUST accurately report if request is completed synchronously or not. The jhc component's producer allows you to make HTTP requests and implement the AsyncProcessor interface. A route that uses both the jetty asynchronous consumer and the jhc asynchronous producer will be a fully asynchronous route and has some nice attributes that can be seen if we take a look at a sequence diagram of the processing route. For the route:
from("jetty:http://localhost:8080/service").to("jhc:http://localhost/service-impl");
The sequence diagram would look something like this:
The diagram simplifies things by making it looks like processors implement the AsyncCallback interface when in reality the AsyncCallback interfaces are inline inner classes, but it illustrates the processing flow and shows how 2 separate threads are used to complete the processing of the original http request. The first thread is synchronous up until processing hits the jhc producer which issues the http request. It then reports that the exchange processing will complete async since it will use a NIO to complete getting the response back. Once the jhc component has received a full response it uses AsyncCallback.done() method to notify the caller. These callback notifications continue up until it reaches the original jetty consumer which then un-parks the http request and completes it by providing the response. Mixing Synchronous and Asynchronous ProcessorsIt is totally possible and reasonable to mix the use of synchronous and asynchronous processors/components. The pipeline processor is the backbone of a Camel processing route. It glues all the processing steps together. It is implemented as an AsyncProcessor and supports interleaving synchronous and asynchronous processors as the processing steps in the pipeline. Lets say we have 2 custom processors, MyValidator and MyTransformation, both of which are synchronous processors. Lets say we want to load file from the data/in directory validate them with the MyValidator() processor, Transform them into JPA java objects using MyTransformation and then insert them into the database using the JPA component. Lets say that the transformation process takes quite a bit of time and we want to allocate 20 threads to do parallel transformations of the input files. The solution is to make use of the thread processor. The thread is AsyncProcessor that forces subsequent processing in asynchronous thread from a thread pool. The route might look like: from("file:data/in").process(new MyValidator()).threads(20).process(new MyTransformation()).to("jpa:PurchaseOrder"); The sequence diagram would look something like this:
You would actually have multiple threads executing the 2nd part of the thread sequence. Staying synchronous in an AsyncProcessorGenerally speaking you get better throughput processing when you process things synchronously. This is due to the fact that starting up an asynchronous thread and doing a context switch to it adds a little bit of of overhead. So it is generally encouraged that AsyncProcessors do as much work as they can synchronously. When they get to a step that would block for a long time, at that point they should return from the process call and let the caller know that it will be completing the call asynchronously. Implementing Virtual Topics on other JMS providersActiveMQ supports Virtual Topics since durable topic subscriptions kinda suck (see this page for more detail) mostly since they don't support Competing Consumers. Most folks want Queue semantics when consuming messages; so that you can support Competing Consumers for load balancing along with things like Message Groups and Exclusive Consumers to preserve ordering or partition the queue across consumers. However if you are using another JMS provider you can implement Virtual Topics by switching to ActiveMQ First here's the ActiveMQ approach.
When using another message broker use the following pattern
What's the Camel Transport for CXFIn CXF you offer or consume a webservice by defining it´s address. The first part of the address specifies the protocol to use. For example address="http://localhost:90000" in an endpoint configuration means your service will be offered using the http protocol on port 9000 of localhost. When you integrate Camel Tranport into CXF you get a new transport "camel". So you can specify address="camel://direct:MyEndpointName" to bind the CXF service address to a camel direct endpoint. Technically speaking Camel transport for CXF is a component which implements the CXF transport API with the Camel core library. This allows you to use camel´s routing engine and integration patterns support smoothly together with your CXF services. Integrate Camel into CXF transport layerTo include the Camel Tranport into your CXF bus you use the CamelTransportFactory. You can do this in Java as well as in Spring. Setting up the Camel Transport in SpringYou can use the following snippet in your applicationcontext if you want to configure anything special. If you only want to activate the camel transport you do not have to do anything in your application context. As soon as you include the camel-cxf jar in your app cxf will scan the jar and load a CamelTransportFactory for you. <bean class="org.apache.camel.component.cxf.transport.CamelTransportFactory"> <property name="bus" ref="cxf" /> <property name="camelContext" ref="camelContext" /> <!-- checkException new added in Camel 2.1 and Camel 1.6.2 --> <!-- If checkException is true , CamelDestination will check the outMessage's exception and set it into camel exchange. You can also override this value in CamelDestination's configuration. The default value is false. This option should be set true when you want to leverage the camel's error handler to deal with fault message --> <property name="checkException" value="true" /> <property name="transportIds"> <list> <value>http://cxf.apache.org/transports/camel</value> </list> </property> </bean> Integrating the Camel Transport in a programmatic wayCamel transport provides a setContext method that you could use to set the Camel context into the transport factory. If you want this factory take effect, you need to register the factory into the CXF bus. Here is a full example for you. import org.apache.cxf.Bus; import org.apache.cxf.BusFactory; import org.apache.cxf.transport.ConduitInitiatorManager; import org.apache.cxf.transport.DestinationFactoryManager; ... BusFactory bf = BusFactory.newInstance(); Bus bus = bf.createBus(); CamelTransportFactory camelTransportFactory = new CamelTransportFactory(); camelTransportFactory.setCamelContext(context) // register the conduit initiator ConduitInitiatorManager cim = bus.getExtension(ConduitInitiatorManager.class); cim.registerConduitInitiator(CamelTransportFactory.TRANSPORT_ID, camelTransportFactory); // register the destination factory DestinationFactoryManager dfm = bus.getExtension(DestinationFactoryManager.class); dfm.registerDestinationFactory(CamelTransportFactory.TRANSPORT_ID, camelTransportFactory); // set or bus as the default bus for cxf BusFactory.setDefaultBus(bus); Configure the destination and conduitNamespaceThe elements used to configure an Camel transport endpoint are defined in the namespace http://cxf.apache.org/transports/camel. It is commonly referred to using the prefix camel. In order to use the Camel transport configuration elements you will need to add the lines shown below to the beans element of your endpoint's configuration file. In addition, you will need to add the configuration elements' namespace to the xsi:schemaLocation attribute. Adding the Configuration Namespace
<beans ...
xmlns:camel="http://cxf.apache.org/transports/camel
...
xsi:schemaLocation="...
http://cxf.apache.org/transports/camel
http://cxf.apache.org/transports/camel.xsd
...>
The destination elementYou configure an Camel transport server endpoint using the camel:destination element and its children. The camel:destination element takes a single attribute, name, the specifies the WSDL port element that corresponds to the endpoint. The value for the name attribute takes the form portQName.camel-destination. The example below shows the camel:destination element that would be used to add configuration for an endpoint that was specified by the WSDL fragment <port binding="widgetSOAPBinding" name="widgetSOAPPort> if the endpoint's target namespace was http://widgets.widgetvendor.net. camel:destination Element
...
<camel:destination name="{http://widgets/widgetvendor.net}widgetSOAPPort.http-destination>
<camelContext id="context" xmlns="http://activemq.apache.org/camel/schema/spring">
<route>
<from uri="direct:EndpointC" />
<to uri="direct:EndpointD" />
</route>
</camelContext>
</camel:destination>
...
The camel:destination element has a number of child elements that specify configuration information. They are described below.
The conduit elementYou configure an Camel transport client using the camel:conduit element and its children. The camel:conduit element takes a single attribute, name, that specifies the WSDL port element that corresponds to the endpoint. The value for the name attribute takes the form portQName.camel-conduit. For example, the code below shows the camel:conduit element that would be used to add configuration for an endpoint that was specified by the WSDL fragment <port binding="widgetSOAPBinding" name="widgetSOAPPort> if the endpoint's target namespace was http://widgets.widgetvendor.net. http-conf:conduit Element ... <camelContext id="conduit_context" xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:EndpointA" /> <to uri="direct:EndpointB" /> </route> </camelContext> <camel:conduit name="{http://widgets/widgetvendor.net}widgetSOAPPort.camel-conduit"> <camel:camelContextRef>conduit_context</camel:camelContextRef> </camel:conduit> <camel:conduit name="*.camel-conduit"> <!-- you can also using the wild card to specify the camel-conduit that you want to configure --> ... </camel:conduit> ... The camel:conduit element has a number of child elements that specify configuration information. They are described below.
Example Using Camel as a load balancer for CXFThis example show how to use the camel load balance feature in CXF, and you need load the configuration file in CXF and publish the endpoints on the address "camel://direct:EndpointA" and "camel://direct:EndpointB" <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://cxf.apache.org/transports/camel" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://cxf.apache.org/transports/camel http://cxf.apache.org/transports/camel.xsd http://camel.apache.org/schema/cxf http://camel.apache.org/schema/cxf/cxfEndpoint.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd "> <bean id = "roundRobinRef" class="org.apache.camel.processor.loadbalancer.RoundRobinLoadBalancer" /> <camelContext id="dest_context" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="jetty:http://localhost:9091/GreeterContext/GreeterPort"/> <loadBalance ref="roundRobinRef"> <to uri="direct:EndpointA"/> <to uri="direct:EndpointB"/> </loadBalance> </route> </camelContext> <!-- Inject the camel context to the Camel transport's destination --> <camel:destination name="{http://apache.org/hello_world_soap_http}CamelPort.camel-destination"> <camel:camelContextRef>dest_context</camel:camelContextRef> </camel:destination> </beans> Complete Howto and Example for attaching Camel to CXFBetter JMS Transport for CXF Webservice using Apache Camel IntroductionWhen sending an Exchange to an Endpoint you can either use a Route or a ProducerTemplate. This works fine in many scenarios. However you may need to guarantee that an exchange is delivered to the same endpoint that you delivered a previous exchange on. For example in the case of delivering a batch of exchanges to a MINA socket you may need to ensure that they are all delivered through the same socket connection. Furthermore once the batch of exchanges have been delivered the protocol requirements may be such that you are responsible for closing the socket. Using a ProducerTo achieve fine grained control over sending exchanges you will need to program directly to a Producer. Your code will look similar to: CamelContext camelContext = ... // Obtain an endpoint and create the producer we will be using. Endpoint endpoint = camelContext.getEndpoint("someuri:etc"); Producer producer = endpoint.createProducer(); producer.start(); try { // For each message to send... Object requestMessage = ... Exchange exchangeToSend = producer.createExchange(); exchangeToSend().setBody(requestMessage); producer.process(exchangeToSend); ... } finally { // Tidy the producer up. producer.stop(); } In the case of using Apache MINA the producer.stop() invocation will cause the socket to be closed. TutorialsThere now follows the documentation on camel tutorials We have a number of tutorials as listed below. The tutorials often comes with source code which is either available in the Camel Download or attached to the wiki page.
Tutorial on Spring Remoting with JMS
PrefaceThis tutorial aims to guide the reader through the stages of creating a project which uses Camel to facilitate the routing of messages from a JMS queue to a Spring service. The route works in a synchronous fashion returning a response to the client.
PrerequisitesThis tutorial uses Maven to setup the Camel project and for dependencies for artifacts. DistributionThis sample is distributed with the Camel distribution as examples/camel-example-spring-jms. AboutThis tutorial is a simple example that demonstrates more the fact how well Camel is seamless integrated with Spring to leverage the best of both worlds. This sample is client server solution using JMS messaging as the transport. The sample has two flavors of servers and also for clients demonstrating different techniques for easy communication. The Server is a JMS message broker that routes incoming messages to a business service that does computations on the received message and returns a response.
We use the following Camel components:
Create the Camel Project
mvn archetype:create -DgroupId=org.example -DartifactId=CamelWithJmsAndSpring Update the POM with DependenciesFirst we need to have dependencies for the core Camel jars, its spring, jms components and finally ActiveMQ as the message broker. <!-- required by both client and server --> <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-core</artifactId> </dependency> <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jms</artifactId> </dependency> <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring</artifactId> </dependency> <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-camel</artifactId> </dependency> As we use spring xml configuration for the ActiveMQ JMS broker we need this dependency: <!-- xbean is required for ActiveMQ broker configuration in the spring xml file --> <dependency> <groupId>org.apache.xbean</groupId> <artifactId>xbean-spring</artifactId> </dependency> Writing the ServerCreate the Spring ServiceFor this example the Spring service (= our business service) on the server will be a simple multiplier which trebles in the received value. public interface Multiplier { /** * Multiplies the given number by a pre-defined constant. * * @param originalNumber The number to be multiplied * @return The result of the multiplication */ int multiply(int originalNumber); } And the implementation of this service is: @Service(value = "multiplier") public class Treble implements Multiplier { public int multiply(final int originalNumber) { return originalNumber * 3; } } Notice that this class has been annotated with the @Service spring annotation. This ensures that this class is registered as a bean in the registry with the given name multiplier. Define the Camel Routespublic class ServerRoutes extends RouteBuilder { @Override public void configure() throws Exception { // route from the numbers queue to our business that is a spring bean registered with the id=multiplier // Camel will introspect the multiplier bean and find the best candidate of the method to invoke. // You can add annotations etc to help Camel find the method to invoke. // As our multiplier bean only have one method its easy for Camel to find the method to use. from("jms:queue:numbers").to("multiplier"); // Camel has several ways to configure the same routing, we have defined some of them here below // as above but with the bean: prefix //from("jms:queue:numbers").to("bean:multiplier"); // beanRef is using explicit bean bindings to lookup the multiplier bean and invoke the multiply method //from("jms:queue:numbers").beanRef("multiplier", "multiply"); // the same as above but expressed as a URI configuration //from("jms:queue:numbers").to("bean:multiplier?methodName=multiply"); } } This defines a Camel route from the JMS queue named numbers to the Spring bean named multiplier. Camel will create a consumer to the JMS queue which forwards all received messages onto the the Spring bean, using the method named multiply. Configure SpringThe Spring config file is placed under META-INF/spring as this is the default location used by the Camel Maven Plugin, which we will later use to run our server. <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:camel="http://camel.apache.org/schema/spring" xmlns:broker="http://activemq.apache.org/schema/core" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core-5.5.0.xsd"> We use Spring annotations for doing IoC dependencies and its component-scan features comes to the rescue as it scans for spring annotations in the given package name: <!-- let Spring do its IoC stuff in this package --> <context:component-scan base-package="org.apache.camel.example.server"/> Camel will of course not be less than Spring in this regard so it supports a similar feature for scanning of Routes. This is configured as shown below. <!-- declare a camel context that scans for classes that is RouteBuilder
in the package org.apache.camel.example.server -->
<camel:camelContext id="camel-server">
<camel:package>org.apache.camel.example.server</camel:package>
<!-- enable JMX connector so we can connect to the server and browse mbeans -->
<!-- Camel will log at INFO level the service URI to use for connecting with jconsole -->
<camel:jmxAgent id="agent" createConnector="true"/>
</camel:camelContext>
The ActiveMQ JMS broker is also configured in this xml file. We set it up to listen on TCP port 61610. <!-- lets configure the ActiveMQ JMS broker server to listen on TCP 61610 --> <broker:broker useJmx="true" persistent="false" brokerName="myBroker"> <broker:transportConnectors> <!-- expose a VM transport for in-JVM transport between AMQ and Camel on the server side --> <broker:transportConnector name="vm" uri="vm://myBroker"/> <!-- expose a TCP transport for clients to use --> <broker:transportConnector name="tcp" uri="tcp://localhost:${tcp.port}"/> </broker:transportConnectors> </broker:broker> As this examples uses JMS then Camel needs a JMS component that is connected with the ActiveMQ broker. This is configured as shown below: <!-- lets configure the Camel ActiveMQ to use the embedded ActiveMQ broker declared above --> <bean id="jms" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="brokerURL" value="vm://myBroker"/> </bean> Notice: The JMS component is configured in standard Spring beans, but the gem is that the bean id can be referenced from Camel routes - meaning we can do routing using the JMS Component by just using jms: prefix in the route URI. What happens is that Camel will find in the Spring Registry for a bean with the id="jms". Since the bean id can have arbitrary name you could have named it id="jmsbroker" and then referenced to it in the routing as from="jmsbroker:queue:numbers).to("multiplier");
Run the ServerThe Server is started using the org.apache.camel.spring.Main class that can start camel-spring application out-of-the-box. The Server can be started in several flavors:
In this sample as there are two servers (with and without AOP) we have prepared some profiles in maven to start the Server of your choice. Writing The ClientsThis sample has three clients demonstrating different Camel techniques for communication
Client Using The ProducerTemplateWe will initially create a client by directly using ProducerTemplate. We will later create a client which uses Spring remoting to hide the fact that messaging is being used. <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://camel.apache.org/schema/spring" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camel:camelContext id="camel-client"> <camel:template id="camelTemplate"/> </camel:camelContext> <!-- Camel JMSProducer to be able to send messages to a remote Active MQ server --> <bean id="jms" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="brokerURL" value="tcp://localhost:61610"/> </bean> The client will not use the Camel Maven Plugin so the Spring XML has been placed in src/main/resources to not conflict with the server configs.
And the CamelClient source code: public static void main(final String[] args) throws Exception { System.out.println("Notice this client requires that the CamelServer is already running!"); ApplicationContext context = new ClassPathXmlApplicationContext("camel-client.xml"); // get the camel template for Spring template style sending of messages (= producer) ProducerTemplate camelTemplate = context.getBean("camelTemplate", ProducerTemplate.class); System.out.println("Invoking the multiply with 22"); // as opposed to the CamelClientRemoting example we need to define the service URI in this java code int response = (Integer)camelTemplate.sendBody("jms:queue:numbers", ExchangePattern.InOut, 22); System.out.println("... the result is: " + response); System.exit(0); } The ProducerTemplate is retrieved from a Spring ApplicationContext and used to manually place a message on the "numbers" JMS queue. The requestBody method will use the exchange pattern InOut, which states that the call should be synchronous, and that the caller expects a response. Before running the client be sure that both the ActiveMQ broker and the CamelServer are running. Client Using Spring RemotingSpring Remoting "eases the development of remote-enabled services". It does this by allowing you to invoke remote services through your regular Java interface, masking that a remote service is being called. <!-- Camel proxy for a given service, in this case the JMS queue --> <camel:proxy id="multiplierProxy" serviceInterface="org.apache.camel.example.server.Multiplier" serviceUrl="jms:queue:numbers"/> The snippet above only illustrates the different and how Camel easily can setup and use Spring Remoting in one line configurations. The proxy will create a proxy service bean for you to use to make the remote invocations. The serviceInterface property details which Java interface is to be implemented by the proxy. serviceUrl defines where messages sent to this proxy bean will be directed. Here we define the JMS endpoint with the "numbers" queue we used when working with Camel template directly. The value of the id property is the name that will be the given to the bean when it is exposed through the Spring ApplicationContext. We will use this name to retrieve the service in our client. I have named the bean multiplierProxy simply to highlight that it is not the same multiplier bean as is being used by CamelServer. They are in completely independent contexts and have no knowledge of each other. As you are trying to mask the fact that remoting is being used in a real application you would generally not include proxy in the name. And the Java client source code: public static void main(final String[] args) { System.out.println("Notice this client requires that the CamelServer is already running!"); ApplicationContext context = new ClassPathXmlApplicationContext("camel-client-remoting.xml"); // just get the proxy to the service and we as the client can use the "proxy" as it was // a local object we are invoking. Camel will under the covers do the remote communication // to the remote ActiveMQ server and fetch the response. Multiplier multiplier = context.getBean("multiplierProxy", Multiplier.class); System.out.println("Invoking the multiply with 33"); int response = multiplier.multiply(33); System.out.println("... the result is: " + response); System.exit(0); } Again, the client is similar to the original client, but with some important differences.
Client Using Message Endpoint EIP PatternThis client uses the Message Endpoint EIP pattern to hide the complexity to communicate to the Server. The Client uses the same simple API to get hold of the endpoint, create an exchange that holds the message, set the payload and create a producer that does the send and receive. All done using the same neutral Camel API for all the components in Camel. So if the communication was socket TCP based you just get hold of a different endpoint and all the java code stays the same. That is really powerful. Okay enough talk, show me the code! public static void main(final String[] args) throws Exception { System.out.println("Notice this client requires that the CamelServer is already running!"); ApplicationContext context = new ClassPathXmlApplicationContext("camel-client.xml"); CamelContext camel = context.getBean("camel-client", CamelContext.class); // get the endpoint from the camel context Endpoint endpoint = camel.getEndpoint("jms:queue:numbers"); // create the exchange used for the communication // we use the in out pattern for a synchronized exchange where we expect a response Exchange exchange = endpoint.createExchange(ExchangePattern.InOut); // set the input on the in body // must you correct type to match the expected type of an Integer object exchange.getIn().setBody(11); // to send the exchange we need an producer to do it for us Producer producer = endpoint.createProducer(); // start the producer so it can operate producer.start(); // let the producer process the exchange where it does all the work in this oneline of code System.out.println("Invoking the multiply with 11"); producer.process(exchange); // get the response from the out body and cast it to an integer int response = exchange.getOut().getBody(Integer.class); System.out.println("... the result is: " + response); // stop and exit the client producer.stop(); System.exit(0); } Switching to a different component is just a matter of using the correct endpoint. So if we had defined a TCP endpoint as: "mina:tcp://localhost:61610" then its just a matter of getting hold of this endpoint instead of the JMS and all the rest of the java code is exactly the same. Run the ClientsThe Clients is started using their main class respectively.
In this sample we start the clients using maven: Also see the Maven pom.xml file how the profiles for the clients is defined. Using the Camel Maven PluginThe Camel Maven Plugin allows you to run your Camel routes directly from Maven. This negates the need to create a host application, as we did with Camel server, simply to start up the container. This can be very useful during development to get Camel routes running quickly. pom.xml
<build>
<plugins>
<plugin>
<groupId>org.apache.camel</groupId>
<artifactId>camel-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
All that is required is a new plugin definition in your Maven POM. As we have already placed our Camel config in the default location (camel-server.xml has been placed in META-INF/spring/) we do not need to tell the plugin where the route definitions are located. Simply run mvn camel:run. Using Camel JMXCamel has extensive support for JMX and allows us to inspect the Camel Server at runtime. As we have enabled the JMXAgent in our tutorial we can fire up the jconsole and connect to the following service URI: service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi/camel. Notice that Camel will log at INFO level the JMX Connector URI:
...
DefaultInstrumentationAgent INFO JMX connector thread started on service:jmx:rmi:///jndi/rmi://claus-acer:1099/jmxrmi/camel
...
In the screenshot below we can see the route and its performance metrics: See AlsoTutorial - camel-example-reportincidentIntroductionCreating this tutorial was inspired by a real life use-case I discussed over the phone with a colleague. He was working at a client whom uses a heavy-weight integration platform from a very large vendor. He was in talks with developer shops to implement a new integration on this platform. His trouble was the shop tripled the price when they realized the platform of choice. So I was wondering how we could do this integration with Camel. Can it be done, without tripling the cost This tutorial is written during the development of the integration. I have decided to start off with a sample that isn't Camel's but standard Java and then plugin Camel as we goes. Just as when people needed to learn Spring you could consume it piece by piece, the same goes with Camel. The target reader is person whom hasn't experience or just started using Camel. Motivation for this tutorialI wrote this tutorial motivated as Camel lacked an example application that was based on the web application deployment model. The entire world hasn't moved to pure OSGi deployments yet. The use-caseThe goal is to allow staff to report incidents into a central administration. For that they use client software where they report the incident and submit it to the central administration. As this is an integration in a transition phase the administration should get these incidents by email whereas they are manually added to the database. The client software should gather the incident and submit the information to the integration platform that in term will transform the report into an email and send it to the central administrator for manual processing. The figure below illustrates this process. The end users reports the incidents using the client applications. The incident is sent to the central integration platform as webservice. The integration platform will process the incident and send an OK acknowledgment back to the client. Then the integration will transform the message to an email and send it to the administration mail server. The users in the administration will receive the emails and take it from there.
In EIP patternsWe distill the use case as EIP patterns: PartsThis tutorial is divided into sections and parts: Section A: Existing Solution, how to slowly use Camel Part 1 - This first part explain how to setup the project and get a webservice exposed using Apache CXF. In fact we don't touch Camel yet. Part 2 - Now we are ready to introduce Camel piece by piece (without using Spring or any XML configuration file) and create the full feature integration. This part will introduce different Camel's concepts and How we can build our solution using them like :
Part 3 - Continued from part 2 where we implement that last part of the solution with the event driven consumer and how to send the email through the Mail component. Section B: The Camel Solution Part 4 - We now turn into the path of Camel where it excels - the routing.
LinksPart 1PrerequisitesThis tutorial uses the following frameworks:
Note: The sample project can be downloaded, see the resources section. Initial Project SetupWe want the integration to be a standard .war application that can be deployed in any web container such as Tomcat, Jetty or even heavy weight application servers such as WebLogic or WebSphere. There fore we start off with the standard Maven webapp project that is created with the following long archetype command: mvn archetype:create -DgroupId=org.apache.camel -DartifactId=camel-example-reportincident -DarchetypeArtifactId=maven-archetype-webapp Notice that the groupId etc. doens't have to be org.apache.camel it can be com.mycompany.whatever. But I have used these package names as the example is an official part of the Camel distribution. Then we have the basic maven folder layout. We start out with the webservice part where we want to use Apache CXF for the webservice stuff. So we add this to the pom.xml
<properties>
<cxf-version>2.1.1</cxf-version>
</properties>
<dependency>
<groupId>org.apache.cxf</groupId>
<artifactId>cxf-rt-core</artifactId>
<version>${cxf-version}</version>
</dependency>
<dependency>
<groupId>org.apache.cxf</groupId>
<artifactId>cxf-rt-frontend-jaxws</artifactId>
<version>${cxf-version}</version>
</dependency>
<dependency>
<groupId>org.apache.cxf</groupId>
<artifactId>cxf-rt-transports-http</artifactId>
<version>${cxf-version}</version>
</dependency>
Developing the WebServiceAs we want to develop webservice with the contract first approach we create our .wsdl file. As this is a example we have simplified the model of the incident to only include 8 fields. In real life the model would be a bit more complex, but not to much. We put the wsdl file in the folder src/main/webapp/WEB-INF/wsdl and name the file report_incident.wsdl. <?xml version="1.0" encoding="ISO-8859-1"?> <wsdl:definitions xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="http://reportincident.example.camel.apache.org" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://reportincident.example.camel.apache.org"> <!-- Type definitions for input- and output parameters for webservice --> <wsdl:types> <xs:schema targetNamespace="http://reportincident.example.camel.apache.org"> <xs:element name="inputReportIncident"> <xs:complexType> <xs:sequence> <xs:element type="xs:string" name="incidentId"/> <xs:element type="xs:string" name="incidentDate"/> <xs:element type="xs:string" name="givenName"/> <xs:element type="xs:string" name="familyName"/> <xs:element type="xs:string" name="summary"/> <xs:element type="xs:string" name="details"/> <xs:element type="xs:string" name="email"/> <xs:element type="xs:string" name="phone"/> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="outputReportIncident"> <xs:complexType> <xs:sequence> <xs:element type="xs:string" name="code"/> </xs:sequence> </xs:complexType> </xs:element> </xs:schema> </wsdl:types> <!-- Message definitions for input and output --> <wsdl:message name="inputReportIncident"> <wsdl:part name="parameters" element="tns:inputReportIncident"/> </wsdl:message> <wsdl:message name="outputReportIncident"> <wsdl:part name="parameters" element="tns:outputReportIncident"/> </wsdl:message> <!-- Port (interface) definitions --> <wsdl:portType name="ReportIncidentEndpoint"> <wsdl:operation name="ReportIncident"> <wsdl:input message="tns:inputReportIncident"/> <wsdl:output message="tns:outputReportIncident"/> </wsdl:operation> </wsdl:portType> <!-- Port bindings to transports and encoding - HTTP, document literal encoding is used --> <wsdl:binding name="ReportIncidentBinding" type="tns:ReportIncidentEndpoint"> <soap:binding transport="http://schemas.xmlsoap.org/soap/http"/> <wsdl:operation name="ReportIncident"> <soap:operation soapAction="http://reportincident.example.camel.apache.org/ReportIncident" style="document"/> <wsdl:input> <soap:body parts="parameters" use="literal"/> </wsdl:input> <wsdl:output> <soap:body parts="parameters" use="literal"/> </wsdl:output> </wsdl:operation> </wsdl:binding> <!-- Service definition --> <wsdl:service name="ReportIncidentService"> <wsdl:port name="ReportIncidentPort" binding="tns:ReportIncidentBinding"> <soap:address location="http://reportincident.example.camel.apache.org"/> </wsdl:port> </wsdl:service> </wsdl:definitions> CXF wsdl2javaThen we integration the CXF wsdl2java generator in the pom.xml so we have CXF generate the needed POJO classes for our webservice contract. <!-- to compile with 1.5 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.5</source> <target>1.5</target> </configuration> </plugin> And then we can add the CXF wsdl2java code generator that will hook into the compile goal so its automatic run all the time: <!-- CXF wsdl2java generator, will plugin to the compile goal --> <plugin> <groupId>org.apache.cxf</groupId> <artifactId>cxf-codegen-plugin</artifactId> <version>${cxf-version}</version> <executions> <execution> <id>generate-sources</id> <phase>generate-sources</phase> <configuration> <sourceRoot>${basedir}/target/generated/src/main/java</sourceRoot> <wsdlOptions> <wsdlOption> <wsdl>${basedir}/src/main/webapp/WEB-INF/wsdl/report_incident.wsdl</wsdl> </wsdlOption> </wsdlOptions> </configuration> <goals> <goal>wsdl2java</goal> </goals> </execution> </executions> </plugin> You are now setup and should be able to compile the project. So running the mvn compile should run the CXF wsdl2java and generate the source code in the folder &{basedir}/target/generated/src/main/java that we specified in the pom.xml above. Since its in the target/generated/src/main/java maven will pick it up and include it in the build process. Configuration of the web.xmlNext up is to configure the web.xml to be ready to use CXF so we can expose the webservice. <!-- the listener that kick-starts Spring --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> And then we have the CXF part where we define the CXF servlet and its URI mappings to which we have chosen that all our webservices should be in the path /webservices/ <!-- CXF servlet --> <servlet> <servlet-name>CXFServlet</servlet-name> <servlet-class>org.apache.cxf.transport.servlet.CXFServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <!-- all our webservices are mapped under this URI pattern --> <servlet-mapping> <servlet-name>CXFServlet</servlet-name> <url-pattern>/webservices/*</url-pattern> </servlet-mapping> Then the last piece of the puzzle is to configure CXF, this is done in a spring XML that we link to fron the web.xml by the standard Spring contextConfigLocation property in the web.xml <!-- location of spring xml files --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:cxf-config.xml</param-value> </context-param> We have named our CXF configuration file cxf-config.xml and its located in the root of the classpath. In Maven land that is we can have the cxf-config.xml file in the src/main/resources folder. We could also have the file located in the WEB-INF folder for instance <param-value>/WEB-INF/cxf-config.xml</param-value>. Getting rid of the old jsp worldThe maven archetype that created the basic folder structure also created a sample .jsp file index.jsp. This file src/main/webapp/index.jsp should be deleted. Configuration of CXFThe cxf-config.xml is as follows: <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jaxws="http://cxf.apache.org/jaxws" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd"> <import resource="classpath:META-INF/cxf/cxf.xml"/> <import resource="classpath:META-INF/cxf/cxf-extension-soap.xml"/> <import resource="classpath:META-INF/cxf/cxf-servlet.xml"/> <!-- implementation of the webservice --> <bean id="reportIncidentEndpoint" class="org.apache.camel.example.reportincident.ReportIncidentEndpointImpl"/> <!-- export the webservice using jaxws --> <jaxws:endpoint id="reportIncident" implementor="#reportIncidentEndpoint" address="/incident" wsdlLocation="/WEB-INF/wsdl/report_incident.wsdl" endpointName="s:ReportIncidentPort" serviceName="s:ReportIncidentService" xmlns:s="http://reportincident.example.camel.apache.org"/> </beans> The configuration is standard CXF and is documented at the Apache CXF website. The 3 import elements is needed by CXF and they must be in the file. Noticed that we have a spring bean reportIncidentEndpoint that is the implementation of the webservice endpoint we let CXF expose. Implementing the ReportIncidentEndpointPhew after all these meta files its time for some java code so we should code the implementor of the webservice. So we fire up mvn compile to let CXF generate the POJO classes for our webservice and we are ready to fire up a Java editor. You can use mvn idea:idea or mvn eclipse:eclipse to create project files for these editors so you can load the project. However IDEA has been smarter lately and can load a pom.xml directly. As we want to quickly see our webservice we implement just a quick and dirty as it can get. At first beware that since its jaxws and Java 1.5 we get annotations for the money, but they reside on the interface so we can remove them from our implementations so its a nice plain POJO again: package org.apache.camel.example.reportincident; /** * The webservice we have implemented. */ public class ReportIncidentEndpointImpl implements ReportIncidentEndpoint { public OutputReportIncident reportIncident(InputReportIncident parameters) { System.out.println("Hello ReportIncidentEndpointImpl is called from " + parameters.getGivenName()); OutputReportIncident out = new OutputReportIncident(); out.setCode("OK"); return out; } } We just output the person that invokes this webservice and returns a OK response. This class should be in the maven source root folder src/main/java under the package name org.apache.camel.example.reportincident. Beware that the maven archetype tool didn't create the src/main/java folder, so you should create it manually. To test if we are home free we run mvn clean compile. Running our webserviceNow that the code compiles we would like to run it in a web container, so we add jetty to our pom.xml so we can run mvn jetty:run: <properties> ... <jetty-version>6.1.1</jetty-version> </properties> <build> <plugins> ... <!-- so we can run mvn jetty:run --> <plugin> <groupId>org.mortbay.jetty</groupId> <artifactId>maven-jetty-plugin</artifactId> <version>${jetty-version}</version> </plugin> Notice: We use Jetty v6.1.1 as never versions has troubles on my laptop. Feel free to try a newer version on your system, but v6.1.1 works flawless. So to see if everything is in order we fire up jetty with mvn jetty:run and if everything is okay you should be able to access http://localhost:8080. So where is the damn webservice then? Well as we did configure the web.xml to instruct the CXF servlet to accept the pattern /webservices/* we should hit this URL to get the attention of CXF: http://localhost:8080/camel-example-reportincident/webservices. Hitting the webserviceNow we have the webservice running in a standard .war application in a standard web container such as Jetty we would like to invoke the webservice and see if we get our code executed. Unfortunately this isn't the easiest task in the world - its not so easy as a REST URL, so we need tools for this. So we fire up our trusty webservice tool SoapUI and let it be the one to fire the webservice request and see the response. Using SoapUI we sent a request to our webservice and we got the expected OK response and the console outputs the System.out so we are ready to code. Remote DebuggingOkay a little sidestep but wouldn't it be cool to be able to debug your code when its fired up under Jetty? As Jetty is started from maven, we need to instruct maven to use debug mode. MAVEN_OPTS=-Xmx512m -XX:MaxPermSize=128m -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005 Then you need to restart Jetty so its stopped with ctrl + c. Remember to start a new shell to pickup the new environment settings. And start jetty again. Then we can from our IDE attach a remote debugger and debug as we want. Then we set a breakpoint in our code ReportIncidentEndpoint and hit the SoapUI once again and we are breaked at the breakpoint where we can inspect the parameters: Adding a unit testOh so much hard work just to hit a webservice, why can't we just use an unit test to invoke our webservice? Yes of course we can do this, and that's the next step. package org.apache.camel.example.reportincident; import junit.framework.TestCase; /** * Plain JUnit test of our webservice. */ public class ReportIncidentEndpointTest extends TestCase { } Here we have a plain old JUnit class. As we want to test webservices we need to start and expose our webservice in the unit test before we can test it. And JAXWS has pretty decent methods to help us here, the code is simple as:
import javax.xml.ws.Endpoint;
...
private static String ADDRESS = "http://localhost:9090/unittest";
protected void startServer() throws Exception {
// We need to start a server that exposes or webservice during the unit testing
// We use jaxws to do this pretty simple
ReportIncidentEndpointImpl server = new ReportIncidentEndpointImpl();
Endpoint.publish(ADDRESS, server);
}
The Endpoint class is the javax.xml.ws.Endpoint that under the covers looks for a provider and in our case its CXF - so its CXF that does the heavy lifting of exposing out webservice on the given URL address. Since our class ReportIncidentEndpointImpl implements the interface ReportIncidentEndpoint that is decorated with all the jaxws annotations it got all the information it need to expose the webservice. Below is the CXF wsdl2java generated interface: /* * */ package org.apache.camel.example.reportincident; import javax.jws.WebMethod; import javax.jws.WebParam; import javax.jws.WebResult; import javax.jws.WebService; import javax.jws.soap.SOAPBinding; import javax.jws.soap.SOAPBinding.ParameterStyle; import javax.xml.bind.annotation.XmlSeeAlso; /** * This class was generated by Apache CXF 2.1.1 * Wed Jul 16 12:40:31 CEST 2008 * Generated source version: 2.1.1 * */ /* * */ @WebService(targetNamespace = "http://reportincident.example.camel.apache.org", name = "ReportIncidentEndpoint") @XmlSeeAlso({ObjectFactory.class}) @SOAPBinding(parameterStyle = SOAPBinding.ParameterStyle.BARE) public interface ReportIncidentEndpoint { /* * */ @SOAPBinding(parameterStyle = SOAPBinding.ParameterStyle.BARE) @WebResult(name = "outputReportIncident", targetNamespace = "http://reportincident.example.camel.apache.org", partName = "parameters") @WebMethod(operationName = "ReportIncident", action = "http://reportincident.example.camel.apache.org/ReportIncident") public OutputReportIncident reportIncident( @WebParam(partName = "parameters", name = "inputReportIncident", targetNamespace = "http://reportincident.example.camel.apache.org") InputReportIncident parameters ); } Next up is to create a webservice client so we can invoke our webservice. For this we actually use the CXF framework directly as its a bit more easier to create a client using this framework than using the JAXWS style. We could have done the same for the server part, and you should do this if you need more power and access more advanced features.
import org.apache.cxf.jaxws.JaxWsProxyFactoryBean;
...
protected ReportIncidentEndpoint createCXFClient() {
// we use CXF to create a client for us as its easier than JAXWS and works
JaxWsProxyFactoryBean factory = new JaxWsProxyFactoryBean();
factory.setServiceClass(ReportIncidentEndpoint.class);
factory.setAddress(ADDRESS);
return (ReportIncidentEndpoint) factory.create();
}
So now we are ready for creating a unit test. We have the server and the client. So we just create a plain simple unit test method as the usual junit style:
public void testRendportIncident() throws Exception {
startServer();
ReportIncidentEndpoint client = createCXFClient();
InputReportIncident input = new InputReportIncident();
input.setIncidentId("123");
input.setIncidentDate("2008-07-16");
input.setGivenName("Claus");
input.setFamilyName("Ibsen");
input.setSummary("bla bla");
input.setDetails("more bla bla");
input.setEmail("davsclaus@apache.org");
input.setPhone("+45 2962 7576");
OutputReportIncident out = client.reportIncident(input);
assertEquals("Response code is wrong", "OK", out.getCode());
}
Now we are nearly there. But if you run the unit test with mvn test then it will fail. Why!!! Well its because that CXF needs is missing some dependencies during unit testing. In fact it needs the web container, so we need to add this to our pom.xml.
<!-- cxf web container for unit testing -->
<dependency>
<groupId>org.apache.cxf</groupId>
<artifactId>cxf-rt-transports-http-jetty</artifactId>
<version>${cxf-version}</version>
<scope>test</scope>
</dependency>
Well what is that, CXF also uses Jetty for unit test - well its just shows how agile, embedable and popular Jetty is. So lets run our junit test with, and it reports: mvn test Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 [INFO] BUILD SUCCESSFUL Yep thats it for now. We have a basic project setup. End of part 1Thanks for being patient and reading all this more or less standard Maven, Spring, JAXWS and Apache CXF stuff. Its stuff that is well covered on the net, but I wanted a full fledged tutorial on a maven project setup that is web service ready with Apache CXF. We will use this as a base for the next part where we demonstrate how Camel can be digested slowly and piece by piece just as it was back in the times when was introduced and was learning the Spring framework that we take for granted today. ResourcesLinksPart 2Adding CamelIn this part we will introduce Camel so we start by adding Camel to our pom.xml:
<properties>
...
<camel-version>1.4.0</camel-version>
</properties>
<!-- camel -->
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
<version>${camel-version}</version>
</dependency>
That's it, only one dependency for now.
Now we turn towards our webservice endpoint implementation where we want to let Camel have a go at the input we receive. As Camel is very non invasive its basically a .jar file then we can just grap Camel but creating a new instance of DefaultCamelContext that is the hearth of Camel its context.
CamelContext camel = new DefaultCamelContext();
In fact we create a constructor in our webservice and add this code:
private CamelContext camel;
public ReportIncidentEndpointImpl() throws Exception {
// create the camel context that is the "heart" of Camel
camel = new DefaultCamelContext();
// add the log component
camel.addComponent("log", new LogComponent());
// start Camel
camel.start();
}
Logging the "Hello World"Here at first we want Camel to log the givenName and familyName parameters we receive, so we add the LogComponent with the key log. And we must start Camel before its ready to act.
Then we change the code in the method that is invoked by Apache CXF when a webservice request arrives. We get the name and let Camel have a go at it in the new method we create sendToCamel:
public OutputReportIncident reportIncident(InputReportIncident parameters) {
String name = parameters.getGivenName() + " " + parameters.getFamilyName();
// let Camel do something with the name
sendToCamelLog(name);
OutputReportIncident out = new OutputReportIncident();
out.setCode("OK");
return out;
}
Next is the Camel code. At first it looks like there are many code lines to do a simple task of logging the name - yes it is. But later you will in fact realize this is one of Camels true power. Its concise API. Hint: The same code can be used for any component in Camel.
private void sendToCamelLog(String name) {
try {
// get the log component
Component component = camel.getComponent("log");
// create an endpoint and configure it.
// Notice the URI parameters this is a common pratice in Camel to configure
// endpoints based on URI.
// com.mycompany.part2 = the log category used. Will log at INFO level as default
Endpoint endpoint = component.createEndpoint("log:com.mycompany.part2");
// create an Exchange that we want to send to the endpoint
Exchange exchange = endpoint.createExchange();
// set the in message payload (=body) with the name parameter
exchange.getIn().setBody(name);
// now we want to send the exchange to this endpoint and we then need a producer
// for this, so we create and start the producer.
Producer producer = endpoint.createProducer();
producer.start();
// process the exchange will send the exchange to the log component, that will process
// the exchange and yes log the payload
producer.process(exchange);
// stop the producer, we want to be nice and cleanup
producer.stop();
} catch (Exception e) {
// we ignore any exceptions and just rethrow as runtime
throw new RuntimeException(e);
}
}
Okay there are code comments in the code block above that should explain what is happening. We run the code by invoking our unit test with maven mvn test, and we should get this log line:
INFO: Exchange[BodyType:String, Body:Claus Ibsen]
Write to file - easy with the same code styleOkay that isn't to impressive, Camel can log
// add the file component
camel.addComponent("file", new FileComponent());
And then we let camel write the payload to the file after we have logged, by creating a new method sendToCamelFile. We want to store the payload in filename with the incident id so we need this parameter also:
// let Camel do something with the name
sendToCamelLog(name);
sendToCamelFile(parameters.getIncidentId(), name);
And then the code that is 99% identical. We have change the URI configuration when we create the endpoint as we pass in configuration parameters to the file component.
private void sendToCamelFile(String incidentId, String name) {
try {
// get the file component
Component component = camel.getComponent("file");
// create an endpoint and configure it.
// Notice the URI parameters this is a common pratice in Camel to configure
// endpoints based on URI.
// file://target instructs the base folder to output the files. We put in the target folder
// then its actumatically cleaned by mvn clean
Endpoint endpoint = component.createEndpoint("file://target");
// create an Exchange that we want to send to the endpoint
Exchange exchange = endpoint.createExchange();
// set the in message payload (=body) with the name parameter
exchange.getIn().setBody(name);
// now a special header is set to instruct the file component what the output filename
// should be
exchange.getIn().setHeader(FileComponent.HEADER_FILE_NAME, "incident-" + incidentId + ".txt");
// now we want to send the exchange to this endpoint and we then need a producer
// for this, so we create and start the producer.
Producer producer = endpoint.createProducer();
producer.start();
// process the exchange will send the exchange to the file component, that will process
// the exchange and yes write the payload to the given filename
producer.process(exchange);
// stop the producer, we want to be nice and cleanup
producer.stop();
} catch (Exception e) {
// we ignore any exceptions and just rethrow as runtime
throw new RuntimeException(e);
}
}
After running our unit test again with mvn test we have a output file in the target folder: D:\demo\part-two>type target\incident-123.txt Claus Ibsen Fully java based configuration of endpointsIn the file example above the configuration was URI based. What if you want 100% java setter based style, well this is of course also possible. We just need to cast to the component specific endpoint and then we have all the setters available:
// create the file endpoint, we cast to FileEndpoint because then we can do
// 100% java settter based configuration instead of the URI sting based
// must pass in an empty string, or part of the URI configuration if wanted
FileEndpoint endpoint = (FileEndpoint)component.createEndpoint("");
endpoint.setFile(new File("target/subfolder"));
endpoint.setAutoCreate(true);
That's it. Now we have used the setters to configure the FileEndpoint that it should store the file in the folder target/subfolder. Of course Camel now stores the file in the subfolder. D:\demo\part-two>type target\subfolder\incident-123.txt Claus Ibsen Lessons learnedOkay I wanted to demonstrate how you can be in 100% control of the configuration and usage of Camel based on plain Java code with no hidden magic or special XML or other configuration files. Just add the camel-core.jar and you are ready to go. You must have noticed that the code for sending a message to a given endpoint is the same for both the log and file, in fact any Camel endpoint. You as the client shouldn't bother with component specific code such as file stuff for file components, jms stuff for JMS messaging etc. This is what the Message Endpoint EIP pattern is all about and Camel solves this very very nice - a key pattern in Camel. Reducing code linesNow that you have been introduced to Camel and one of its masterpiece patterns solved elegantly with the Message Endpoint its time to give productive and show a solution in fewer code lines, in fact we can get it down to 5, 4, 3, 2 .. yes only 1 line of code. The key is the ProducerTemplate that is a Spring'ish xxxTemplate based producer. Meaning that it has methods to send messages to any Camel endpoints. First of all we need to get hold of such a template and this is done from the CamelContext
private ProducerTemplate template;
public ReportIncidentEndpointImpl() throws Exception {
...
// get the ProducerTemplate thst is a Spring'ish xxxTemplate based producer for very
// easy sending exchanges to Camel.
template = camel.createProducerTemplate();
// start Camel
camel.start();
}
Now we can use template for sending payloads to any endpoint in Camel. So all the logging gabble can be reduced to:
template.sendBody("log:com.mycompany.part2.easy", name);
And the same goes for the file, but we must also send the header to instruct what the output filename should be:
String filename = "easy-incident-" + incidentId + ".txt";
template.sendBodyAndHeader("file://target/subfolder", name, FileComponent.HEADER_FILE_NAME, filename);
Reducing even more code linesWell we got the Camel code down to 1-2 lines for sending the message to the component that does all the heavy work of wring the message to a file etc. But we still got 5 lines to initialize Camel.
camel = new DefaultCamelContext();
camel.addComponent("log", new LogComponent());
camel.addComponent("file", new FileComponent());
template = camel.createProducerTemplate();
camel.start();
This can also be reduced. All the standard components in Camel is auto discovered on-the-fly so we can remove these code lines and we are down to 3 lines.
Okay back to the 3 code lines:
camel = new DefaultCamelContext();
template = camel.createProducerTemplate();
camel.start();
Later will we see how we can reduce this to ... in fact 0 java code lines. But the 3 lines will do for now. Message TranslationOkay lets head back to the over goal of the integration. Looking at the EIP diagrams at the introduction page we need to be able to translate the incoming webservice to an email. Doing so we need to create the email body. When doing the message translation we could put up our sleeves and do it manually in pure java with a StringBuilder such as:
private String createMailBody(InputReportIncident parameters) {
StringBuilder sb = new StringBuilder();
sb.append("Incident ").append(parameters.getIncidentId());
sb.append(" has been reported on the ").append(parameters.getIncidentDate());
sb.append(" by ").append(parameters.getGivenName());
sb.append(" ").append(parameters.getFamilyName());
// and the rest of the mail body with more appends to the string builder
return sb.toString();
}
But as always it is a hardcoded template for the mail body and the code gets kinda ugly if the mail message has to be a bit more advanced. But of course it just works out-of-the-box with just classes already in the JDK. Lets use a template language instead such as Apache Velocity. As Camel have a component for Velocity integration we will use this component. Looking at the Component List overview we can see that camel-velocity component uses the artifactId camel-velocity so therefore we need to add this to the pom.xml
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-velocity</artifactId>
<version>${camel-version}</version>
</dependency>
And now we have a Spring conflict as Apache CXF is dependent on Spring 2.0.8 and camel-velocity is dependent on Spring 2.5.5. To remedy this we could wrestle with the pom.xml with excludes settings in the dependencies or just bring in another dependency camel-spring:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-spring</artifactId>
<version>${camel-version}</version>
</dependency>
In fact camel-spring is such a vital part of Camel that you will end up using it in nearly all situations - we will look into how well Camel is seamless integration with Spring in part 3. For now its just another dependency. We create the mail body with the Velocity template and create the file src/main/resources/MailBody.vm. The content in the MailBody.vm file is: Incident $body.incidentId has been reported on the $body.incidentDate by $body.givenName $body.familyName. The person can be contact by: - email: $body.email - phone: $body.phone Summary: $body.summary Details: $body.details This is an auto generated email. You can not reply. Letting Camel creating the mail body and storing it as a file is as easy as the following 3 code lines:
private void generateEmailBodyAndStoreAsFile(InputReportIncident parameters) {
// generate the mail body using velocity template
// notice that we just pass in our POJO (= InputReportIncident) that we
// got from Apache CXF to Velocity.
Object response = template.sendBody("velocity:MailBody.vm", parameters);
// Note: the response is a String and can be cast to String if needed
// store the mail in a file
String filename = "mail-incident-" + parameters.getIncidentId() + ".txt";
template.sendBodyAndHeader("file://target/subfolder", response, FileComponent.HEADER_FILE_NAME, filename);
}
What is impressive is that we can just pass in our POJO object we got from Apache CXF to Velocity and it will be able to generate the mail body with this object in its context. Thus we don't need to prepare anything before we let Velocity loose and generate our mail body. Notice that the template method returns a object with out response. This object contains the mail body as a String object. We can cast to String if needed. If we run our unit test with mvn test we can in fact see that Camel has produced the file and we can type its content: D:\demo\part-two>type target\subfolder\mail-incident-123.txt Incident 123 has been reported on the 2008-07-16 by Claus Ibsen. The person can be contact by: - email: davsclaus@apache.org - phone: +45 2962 7576 Summary: bla bla Details: more bla bla This is an auto generated email. You can not reply. First part of the solutionWhat we have seen here is actually what it takes to build the first part of the integration flow. Receiving a request from a webservice, transform it to a mail body and store it to a file, and return an OK response to the webservice. All possible within 10 lines of code. So lets wrap it up here is what it takes: /** * The webservice we have implemented. */ public class ReportIncidentEndpointImpl implements ReportIncidentEndpoint { private CamelContext camel; private ProducerTemplate template; public ReportIncidentEndpointImpl() throws Exception { // create the camel context that is the "heart" of Camel camel = new DefaultCamelContext(); // get the ProducerTemplate thst is a Spring'ish xxxTemplate based producer for very // easy sending exchanges to Camel. template = camel.createProducerTemplate(); // start Camel camel.start(); } public OutputReportIncident reportIncident(InputReportIncident parameters) { // transform the request into a mail body Object mailBody = template.sendBody("velocity:MailBody.vm", parameters); // store the mail body in a file String filename = "mail-incident-" + parameters.getIncidentId() + ".txt"; template.sendBodyAndHeader("file://target/subfolder", mailBody, FileComponent.HEADER_FILE_NAME, filename); // return an OK reply OutputReportIncident out = new OutputReportIncident(); out.setCode("OK"); return out; } } Okay I missed by one, its in fact only 9 lines of java code and 2 fields. End of part 2I know this is a bit different introduction to Camel to how you can start using it in your projects just as a plain java .jar framework that isn't invasive at all. I took you through the coding parts that requires 6 - 10 lines to send a message to an endpoint, buts it's important to show the Message Endpoint EIP pattern in action and how its implemented in Camel. Yes of course Camel also has to one liners that you can use, and will use in your projects for sending messages to endpoints. This part has been about good old plain java, nothing fancy with Spring, XML files, auto discovery, OGSi or other new technologies. I wanted to demonstrate the basic building blocks in Camel and how its setup in pure god old fashioned Java. There are plenty of eye catcher examples with one liners that does more than you can imagine - we will come there in the later parts. Okay part 3 is about building the last pieces of the solution and now it gets interesting since we have to wrestle with the event driven consumer. ResourcesLinksPart 3RecapLets just recap on the solution we have now: public class ReportIncidentEndpointImpl implements ReportIncidentEndpoint { private CamelContext camel; private ProducerTemplate template; public ReportIncidentEndpointImpl() throws Exception { // create the camel context that is the "heart" of Camel camel = new DefaultCamelContext(); // get the ProducerTemplate thst is a Spring'ish xxxTemplate based producer for very // easy sending exchanges to Camel. template = camel.createProducerTemplate(); // start Camel camel.start(); } /** * This is the last solution displayed that is the most simple */ public OutputReportIncident reportIncident(InputReportIncident parameters) { // transform the request into a mail body Object mailBody = template.sendBody("velocity:MailBody.vm", parameters); // store the mail body in a file String filename = "mail-incident-" + parameters.getIncidentId() + ".txt"; template.sendBodyAndHeader("file://target/subfolder", mailBody, FileComponent.HEADER_FILE_NAME, filename); // return an OK reply OutputReportIncident out = new OutputReportIncident(); out.setCode("OK"); return out; } } This completes the first part of the solution: receiving the message using webservice, transform it to a mail body and store it as a text file. Adding the Event Driven ConsumerWe want to add the consumer to our integration that listen for new files, we do this by creating a private method where the consumer code lives. We must register our consumer in Camel before its started so we need to add, and there fore we call the method addMailSenderConsumer in the constructor below:
public ReportIncidentEndpointImpl() throws Exception {
// create the camel context that is the "heart" of Camel
camel = new DefaultCamelContext();
// get the ProducerTemplate thst is a Spring'ish xxxTemplate based producer for very
// easy sending exchanges to Camel.
template = camel.createProducerTemplate();
// add the event driven consumer that will listen for mail files and process them
addMailSendConsumer();
// start Camel
camel.start();
}
The consumer needs to be consuming from an endpoint so we grab the endpoint from Camel we want to consume. It's file://target/subfolder. Don't be fooled this endpoint doesn't have to 100% identical to the producer, i.e. the endpoint we used in the previous part to create and store the files. We could change the URL to include some options, and to make it more clear that it's possible we setup a delay value to 10 seconds, and the first poll starts after 2 seconds. This is done by adding ?consumer.delay=10000&consumer.initialDelay=2000 to the URL.
When we have the endpoint we can create the consumer (just as in part 1 where we created a producer}. Creating the consumer requires a Processor where we implement the java code what should happen when a message arrives. To get the mail body as a String object we can use the getBody method where we can provide the type we want in return.
Sending the email is still left to be implemented, we will do this later. And finally we must remember to start the consumer otherwise its not active and won't listen for new files.
private void addMailSendConsumer() throws Exception {
// Grab the endpoint where we should consume. Option - the first poll starts after 2 seconds
Endpoint endpint = camel.getEndpoint("file://target/subfolder?consumer.initialDelay=2000");
// create the event driven consumer
// the Processor is the code what should happen when there is an event
// (think it as the onMessage method)
Consumer consumer = endpint.createConsumer(new Processor() {
public void process(Exchange exchange) throws Exception {
// get the mail body as a String
String mailBody = exchange.getIn().getBody(String.class);
// okay now we are read to send it as an email
System.out.println("Sending email..." + mailBody);
}
});
// star the consumer, it will listen for files
consumer.start();
}
Before we test it we need to be aware that our unit test is only catering for the first part of the solution, receiving the message with webservice, transforming it using Velocity and then storing it as a file - it doesn't test the Event Driven Consumer we just added. As we are eager to see it in action, we just do a common trick adding some sleep in our unit test, that gives our Event Driven Consumer time to react and print to System.out. We will later refine the test:
public void testRendportIncident() throws Exception {
...
OutputReportIncident out = client.reportIncident(input);
assertEquals("Response code is wrong", "OK", out.getCode());
// give the event driven consumer time to react
Thread.sleep(10 * 1000);
}
We run the test with mvn clean test and have eyes fixed on the console output. 2008-07-19 12:09:24,140 [mponent@1f12c4e] DEBUG FileProcessStrategySupport - Locking the file: target\subfolder\mail-incident-123.txt ... Sending email...Incident 123 has been reported on the 2008-07-16 by Claus Ibsen. The person can be contact by: - email: davsclaus@apache.org - phone: +45 2962 7576 Summary: bla bla Details: more bla bla This is an auto generated email. You can not reply. 2008-07-19 12:09:24,156 [mponent@1f12c4e] DEBUG FileConsumer - Done processing file: target\subfolder\mail-incident-123.txt. Status is: OK Sending the emailSending the email requires access to a SMTP mail server, but the implementation code is very simple:
private void sendEmail(String body) {
// send the email to your mail server
String url = "smtp://someone@localhost?password=secret&to=incident@mycompany.com";
template.sendBodyAndHeader(url, body, "subject", "New incident reported");
}
And just invoke the method from our consumer:
// okay now we are read to send it as an email
System.out.println("Sending email...");
sendEmail(mailBody);
System.out.println("Email sent");
Unit testing mailFor unit testing the consumer part we will use a mock mail framework, so we add this to our pom.xml:
<!-- unit testing mail using mock -->
<dependency>
<groupId>org.jvnet.mock-javamail</groupId>
<artifactId>mock-javamail</artifactId>
<version>1.7</version>
<scope>test</scope>
</dependency>
Then we prepare our integration to run with or without the consumer enabled. We do this to separate the route into the two parts:
So we change the constructor code a bit:
public ReportIncidentEndpointImpl() throws Exception {
init(true);
}
public ReportIncidentEndpointImpl(boolean enableConsumer) throws Exception {
init(enableConsumer);
}
private void init(boolean enableConsumer) throws Exception {
// create the camel context that is the "heart" of Camel
camel = new DefaultCamelContext();
// get the ProducerTemplate thst is a Spring'ish xxxTemplate based producer for very
// easy sending exchanges to Camel.
template = camel.createProducerTemplate();
// add the event driven consumer that will listen for mail files and process them
if (enableConsumer) {
addMailSendConsumer();
}
// start Camel
camel.start();
}
Then remember to change the ReportIncidentEndpointTest to pass in false in the ReportIncidentEndpointImpl constructor. Adding new unit testWe are now ready to add a new unit test that tests the consumer part so we create a new test class that has the following code structure: /** * Plain JUnit test of our consumer. */ public class ReportIncidentConsumerTest extends TestCase { private ReportIncidentEndpointImpl endpoint; public void testConsumer() throws Exception { // we run this unit test with the consumer, hence the true parameter endpoint = new ReportIncidentEndpointImpl(true); } } As we want to test the consumer that it can listen for files, read the file content and send it as an email to our mailbox we will test it by asserting that we receive 1 mail in our mailbox and that the mail is the one we expect. To do so we need to grab the mailbox with the mockmail API. This is done as simple as:
public void testConsumer() throws Exception {
// we run this unit test with the consumer, hence the true parameter
endpoint = new ReportIncidentEndpointImpl(true);
// get the mailbox
Mailbox box = Mailbox.get("incident@mycompany.com");
assertEquals("Should not have mails", 0, box.size());
How do we trigger the consumer? Well by creating a file in the folder it listen for. So we could use plain java.io.File API to create the file, but wait isn't there an smarter solution? ... yes Camel of course. Camel can do amazing stuff in one liner codes with its ProducerTemplate, so we need to get a hold of this baby. We expose this template in our ReportIncidentEndpointImpl but adding this getter:
protected ProducerTemplate getTemplate() {
return template;
}
Then we can use the template to create the file in one code line:
// drop a file in the folder that the consumer listen
// here is a trick to reuse Camel! so we get the producer template and just
// fire a message that will create the file for us
endpoint.getTemplate().sendBodyAndHeader("file://target/subfolder?append=false", "Hello World",
FileComponent.HEADER_FILE_NAME, "mail-incident-test.txt");
Then we just need to wait a little for the consumer to kick in and do its work and then we should assert that we got the new mail. Easy as just:
// let the consumer have time to run
Thread.sleep(3 * 1000);
// get the mock mailbox and check if we got mail ;)
assertEquals("Should have got 1 mail", 1, box.size());
assertEquals("Subject wrong", "New incident reported", box.get(0).getSubject());
assertEquals("Mail body wrong", "Hello World", box.get(0).getContent());
}
The final class for the unit test is: /** * Plain JUnit test of our consumer. */ public class ReportIncidentConsumerTest extends TestCase { private ReportIncidentEndpointImpl endpoint; public void testConsumer() throws Exception { // we run this unit test with the consumer, hence the true parameter endpoint = new ReportIncidentEndpointImpl(true); // get the mailbox Mailbox box = Mailbox.get("incident@mycompany.com"); assertEquals("Should not have mails", 0, box.size()); // drop a file in the folder that the consumer listen // here is a trick to reuse Camel! so we get the producer template and just // fire a message that will create the file for us endpoint.getTemplate().sendBodyAndHeader("file://target/subfolder?append=false", "Hello World", FileComponent.HEADER_FILE_NAME, "mail-incident-test.txt"); // let the consumer have time to run Thread.sleep(3 * 1000); // get the mock mailbox and check if we got mail ;) assertEquals("Should have got 1 mail", 1, box.size()); assertEquals("Subject wrong", "New incident reported", box.get(0).getSubject()); assertEquals("Mail body wrong", "Hello World", box.get(0).getContent()); } } End of part 3Okay we have reached the end of part 3. For now we have only scratched the surface of what Camel is and what it can do. We have introduced Camel into our integration piece by piece and slowly added more and more along the way. And the most important is: you as the developer never lost control. We hit a sweet spot in the webservice implementation where we could write our java code. Adding Camel to the mix is just to use it as a regular java code, nothing magic. We were in control of the flow, we decided when it was time to translate the input to a mail body, we decided when the content should be written to a file. This is very important to not lose control, that the bigger and heavier frameworks tend to do. No names mentioned, but boy do developers from time to time dislike these elephants. And Camel is no elephant. I suggest you download the samples from part 1 to 3 and try them out. It is great basic knowledge to have in mind when we look at some of the features where Camel really excel - the routing domain language. From part 1 to 3 we touched concepts such as::
ResourcesLinksPart 4IntroductionThis section is about regular Camel. The examples presented here in this section is much more in common of all the examples we have in the Camel documentation.
RoutingCamel is particular strong as a light-weight and agile routing and mediation framework. In this part we will introduce the routing concept and how we can introduce this into our solution. Before we jump into it, we want to state that this tutorial is about Developers not loosing control. In my humble experience one of the key fears of developers is that they are forced into a tool/framework where they loose control and/or power, and the possible is now impossible. So in this part we stay clear with this vision and our starting point is as follows:
So the starting point is: /** * The webservice we have implemented. */ public class ReportIncidentEndpointImpl implements ReportIncidentEndpoint { /** * This is the last solution displayed that is the most simple */ public OutputReportIncident reportIncident(InputReportIncident parameters) { // WE ARE HERE !!! return null; } } Yes we have a simple plain Java class where we have the implementation of the webservice. The cursor is blinking at the WE ARE HERE block and this is where we feel home. More or less any Java Developers have implemented webservices using a stack such as: Apache AXIS, Apache CXF or some other quite popular framework. They all allow the developer to be in control and implement the code logic as plain Java code. Camel of course doesn't enforce this to be any different. Okay the boss told us to implement the solution from the figure in the Introduction page and we are now ready to code. RouteBuilderRouteBuilder is the hearth in Camel of the Java DSL routing. This class does all the heavy lifting of supporting EIP verbs for end-users to express the routing. It does take a little while to get settled and used to, but when you have worked with it for a while you will enjoy its power and realize it is in fact a little language inside Java itself. Camel is the only integration framework we are aware of that has Java DSL, all the others are usually only XML based. As an end-user you usually use the RouteBuilder as of follows:
So we create a new class ReportIncidentRoutes and implement the first part of the routing: import org.apache.camel.builder.RouteBuilder; public class ReportIncidentRoutes extends RouteBuilder { public void configure() throws Exception { // direct:start is a internal queue to kick-start the routing in our example // we use this as the starting point where you can send messages to direct:start from("direct:start") // to is the destination we send the message to our velocity endpoint // where we transform the mail body .to("velocity:MailBody.vm"); } } What to notice here is the configure method. Here is where all the action is. Here we have the Java DSL langauge, that is expressed using the fluent builder syntax that is also known from Hibernate when you build the dynamic queries etc. What you do is that you can stack methods separating with the dot. In the example above we have a very common routing, that can be distilled from pseudo verbs to actual code with:
from("direct:start") is the consumer that is kick-starting our routing flow. It will wait for messages to arrive on the direct queue and then dispatch the message. So what we have implemented so far with our ReportIncidentRoutes RouteBuilder is this part of the picture: Adding the RouteBuilderNow we have our RouteBuilder we need to add/connect it to our CamelContext that is the hearth of Camel. So turning back to our webservice implementation class ReportIncidentEndpointImpl we add this constructor to the code, to create the CamelContext and add the routes from our route builder and finally to start it.
private CamelContext context;
public ReportIncidentEndpointImpl() throws Exception {
// create the context
context = new DefaultCamelContext();
// append the routes to the context
context.addRoutes(new ReportIncidentRoutes());
// at the end start the camel context
context.start();
}
Okay how do you use the routes then? Well its just as before we use a ProducerTemplate to send messages to Endpoints, so we just send to the direct:start endpoint and it will take it from there.
/**
* This is the last solution displayed that is the most simple
*/
public OutputReportIncident reportIncident(InputReportIncident parameters) {
Object mailBody = context.createProducerTemplate().sendBody("direct:start", parameters);
System.out.println("Body:" + mailBody);
// return an OK reply
OutputReportIncident out = new OutputReportIncident();
out.setCode("OK");
return out;
}
Notice that we get the producer template using the createProducerTemplate method on the CamelContext. Then we send the input parameters to the direct:start endpoint and it will route it to the velocity endpoint that will generate the mail body. Since we use direct as the consumer endpoint (=from) and its a synchronous exchange we will get the response back from the route. And the response is of course the output from the velocity endpoint.
We have now completed this part of the picture: Unit testingNow is the time we would like to unit test what we got now. So we call for camel and its great test kit. For this to work we need to add it to the pom.xml
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
<version>1.4.0</version>
<scope>test</scope>
<type>test-jar</type>
</dependency>
After adding it to the pom.xml you should refresh your Java Editor so it pickups the new jar. Then we are ready to create out unit test class. package org.apache.camel.example.reportincident; import org.apache.camel.ContextTestSupport; import org.apache.camel.builder.RouteBuilder; /** * Unit test of our routes */ public class ReportIncidentRoutesTest extends ContextTestSupport { } ContextTestSupport is a supporting unit test class for much easier unit testing with Apache Camel. The class is extending JUnit TestCase itself so you get all its glory. What we need to do now is to somehow tell this unit test class that it should use our route builder as this is the one we gonna test. So we do this by implementing the createRouteBuilder method.
@Override
protected RouteBuilder createRouteBuilder() throws Exception {
return new ReportIncidentRoutes();
}
That is easy just return an instance of our route builder and this unit test will use our routes.
We then code our unit test method that sends a message to the route and assert that its transformed to the mail body using the Velocity template.
public void testTransformMailBody() throws Exception {
// create a dummy input with some input data
InputReportIncident parameters = createInput();
// send the message (using the sendBody method that takes a parameters as the input body)
// to "direct:start" that kick-starts the route
// the response is returned as the out object, and its also the body of the response
Object out = context.createProducerTemplate().sendBody("direct:start", parameters);
// convert the response to a string using camel converters. However we could also have casted it to
// a string directly but using the type converters ensure that Camel can convert it if it wasn't a string
// in the first place. The type converters in Camel is really powerful and you will later learn to
// appreciate them and wonder why its not build in Java out-of-the-box
String body = context.getTypeConverter().convertTo(String.class, out);
// do some simple assertions of the mail body
assertTrue(body.startsWith("Incident 123 has been reported on the 2008-07-16 by Claus Ibsen."));
}
/**
* Creates a dummy request to be used for input
*/
protected InputReportIncident createInput() {
InputReportIncident input = new InputReportIncident();
input.setIncidentId("123");
input.setIncidentDate("2008-07-16");
input.setGivenName("Claus");
input.setFamilyName("Ibsen");
input.setSummary("bla bla");
input.setDetails("more bla bla");
input.setEmail("davsclaus@apache.org");
input.setPhone("+45 2962 7576");
return input;
}
Adding the File BackupThe next piece of puzzle that is missing is to store the mail body as a backup file. So we turn back to our route and the EIP patterns. We use the Pipes and Filters pattern here to chain the routing as:
public void configure() throws Exception {
from("direct:start")
.to("velocity:MailBody.vm")
// using pipes-and-filters we send the output from the previous to the next
.to("file://target/subfolder");
}
Notice that we just add a 2nd .to on the newline. Camel will default use the Pipes and Filters pattern here when there are multi endpoints chained liked this. We could have used the pipeline verb to let out stand out that its the Pipes and Filters pattern such as:
from("direct:start")
// using pipes-and-filters we send the output from the previous to the next
.pipeline("velocity:MailBody.vm", "file://target/subfolder");
But most people are using the multi .to style instead. We re-run out unit test and verifies that it still passes: Running org.apache.camel.example.reportincident.ReportIncidentRoutesTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.157 sec But hey we have added the file producer endpoint and thus a file should also be created as the backup file. If we look in the target/subfolder we can see that something happened. Setting the filenameFor starters we show the simple solution and build from there. We start by setting a constant filename, just to verify that we are on the right path, to instruct the file producer what filename to use. The file producer uses a special header FileComponent.HEADER_FILE_NAME to set the filename. What we do is to send the header when we "kick-start" the routing as the header will be propagated from the direct queue to the file producer. What we need to do is to use the ProducerTemplate.sendBodyAndHeader method that takes both a body and a header. So we change out webservice code to include the filename also:
public OutputReportIncident reportIncident(InputReportIncident parameters) {
// create the producer template to use for sending messages
ProducerTemplate producer = context.createProducerTemplate();
// send the body and the filename defined with the special header key
Object mailBody = producer.sendBodyAndHeader("direct:start", parameters, FileComponent.HEADER_FILE_NAME, "incident.txt");
System.out.println("Body:" + mailBody);
// return an OK reply
OutputReportIncident out = new OutputReportIncident();
out.setCode("OK");
return out;
}
However we could also have used the route builder itself to configure the constant filename as shown below:
public void configure() throws Exception {
from("direct:start")
.to("velocity:MailBody.vm")
// set the filename to a constant before the file producer receives the message
.setHeader(FileComponent.HEADER_FILE_NAME, constant("incident.txt"))
.to("file://target/subfolder");
}
But Camel can be smarter and we want to dynamic set the filename based on some of the input parameters, how can we do this? Using Bean Language to compute the filenameFirst we create our plain java class that computes the filename, and it has 100% no dependencies to Camel what so ever. /** * Plain java class to be used for filename generation based on the reported incident */ public class FilenameGenerator { public String generateFilename(InputReportIncident input) { // compute the filename return "incident-" + input.getIncidentId() + ".txt"; } } The class is very simple and we could easily create unit tests for it to verify that it works as expected. So what we want now is to let Camel invoke this class and its generateFilename with the input parameters and use the output as the filename. Pheeeww is this really possible out-of-the-box in Camel? Yes it is. So lets get on with the show. We have the code that computes the filename, we just need to call it from our route using the Bean Language:
public void configure() throws Exception {
from("direct:start")
// set the filename using the bean language and call the FilenameGenerator class.
// the 2nd null parameter is optional methodname, to be used to avoid ambiguity.
// if not provided Camel will try to figure out the best method to invoke, as we
// only have one method this is very simple
.setHeader(FileComponent.HEADER_FILE_NAME, BeanLanguage.bean(FilenameGenerator.class, null))
.to("velocity:MailBody.vm")
.to("file://target/subfolder");
}
Notice that we use the bean language where we supply the class with our bean to invoke. Camel will instantiate an instance of the class and invoke the suited method. For completeness and ease of code readability we add the method name as the 2nd parameter
.setHeader(FileComponent.HEADER_FILE_NAME, BeanLanguage.bean(FilenameGenerator.class, "generateFilename"))
Then other developers can understand what the parameter is, instead of null. Now we have a nice solution, but as a sidetrack I want to demonstrate the Camel has other languages out-of-the-box, and that scripting language is a first class citizen in Camel where it etc. can be used in content based routing. However we want it to be used for the filename generation.
Whatever worked for you we have now implemented the backup of the data files: Sending the emailWhat we need to do before the solution is completed is to actually send the email with the mail body we generated and stored as a file. In the previous part we did this with a File consumer, that we manually added to the CamelContext. We can do this quite easily with the routing. import org.apache.camel.builder.RouteBuilder; public class ReportIncidentRoutes extends RouteBuilder { public void configure() throws Exception { // first part from the webservice -> file backup from("direct:start") .setHeader(FileComponent.HEADER_FILE_NAME, bean(FilenameGenerator.class, "generateFilename")) .to("velocity:MailBody.vm") .to("file://target/subfolder"); // second part from the file backup -> send email from("file://target/subfolder") // set the subject of the email .setHeader("subject", constant("new incident reported")) // send the email .to("smtp://someone@localhost?password=secret&to=incident@mycompany.com"); } } The last 3 lines of code does all this. It adds a file consumer from("file://target/subfolder"), sets the mail subject, and finally send it as an email. The DSL is really powerful where you can express your routing integration logic. We have now completed the integration: ConclusionWe have just briefly touched the routing in Camel and shown how to implement them using the fluent builder syntax in Java. There is much more to the routing in Camel than shown here, but we are learning step by step. We continue in part 5. See you there. ResourcesLinksBetter JMS Transport for CXF Webservice using Apache CamelConfiguring JMS in Apache CXF before Version 2.1.3 is possible but not really easy or nice. This article shows how to use Apache Camel to provide a better JMS Transport for CXF. Update: Since CXF 2.1.3 there is a new way of configuring JMS (Using the JMSConfigFeature). It makes JMS config for CXF as easy as with Camel. Using Camel for JMS is still a good idea if you want to use the rich feature of Camel for routing and other Integration Scenarios that CXF does not support. So how to connect Apache Camel and CXFThe best way to connect Camel and CXF is using the Camel transport for CXF. This is a camel module that registers with cxf as a new transport. It is quite easy to configure. <bean class="org.apache.camel.component.cxf.transport.CamelTransportFactory"> <property name="bus" ref="cxf" /> <property name="camelContext" ref="camelContext" /> <property name="transportIds"> <list> <value>http://cxf.apache.org/transports/camel</value> </list> </property> </bean> This bean registers with CXF and provides a new transport prefix camel:// that can be used in CXF address configurations. The bean references a bean cxf which will be already present in your config. The other refrenceis a camel context. We will later define this bean to provide the routing config. How is JMS configured in CamelIn camel you need two things to configure JMS. A ConnectionFactory and a JMSComponent. As ConnectionFactory you can simply set up the normal Factory your JMS provider offers or bind a JNDI ConnectionFactory. In this example we use the ConnectionFactory provided by ActiveMQ. <bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="tcp://localhost:61616" /> </bean> Then we set up the JMSComponent. It offers a new transport prefix to camel that we simply call jms. If we need several JMSComponents we can differentiate them by their name. <bean id="jms" class="org.apache.camel.component.jms.JmsComponent"> <property name="connectionFactory" ref="jmsConnectionFactory" /> <property name="useMessageIDAsCorrelationID" value="true" /> </bean> You can find more details about the JMSComponent at the Camel Wiki. For example you find the complete configuration options and a JNDI sample there. Setting up the CXF clientWe will configure a simple CXF webservice client. It will use stub code generated from a wsdl. The webservice client will be configured to use JMS directly. You can also use a direct: Endpoint and do the routing to JMS in the Camel Context. <client id="CustomerService" xmlns="http://cxf.apache.org/jaxws" xmlns:customer="http://customerservice.example.com/" serviceName="customer:CustomerServiceService" endpointName="customer:CustomerServiceEndpoint" address="camel:jms:queue:CustomerService" serviceClass="com.example.customerservice.CustomerService"> </client> We explicitly configure serviceName and endpointName so they are not read from the wsdl. The names we use are arbitrary and have no further function but we set them to look nice. The serviceclass points to the service interface that was generated from the wsdl. Now the important thing is address. Here we tell cxf to use the camel transport, use the JmsComponent who registered the prefix "jms" and use the queue "CustomerService". Setting up the CamelContextAs we do not need additional routing an empty CamelContext bean will suffice. <camelContext id="camelContext" xmlns="http://activemq.apache.org/camel/schema/spring"> </camelContext> Running the Example
ConclusionAs you have seen in this example you can use Camel to connect services to JMS easily while being able to also use the rich integration features of Apache Camel. Tutorial using Axis 1.4 with Apache Camel
PrerequisitesThis tutorial uses Maven 2 to setup the Camel project and for dependencies for artifacts. DistributionThis sample is distributed with the Camel 1.5 distribution as examples/camel-example-axis. IntroductionApache Axis is/was widely used as a webservice framework. So in line with some of the other tutorials to demonstrate how Camel is not an invasive framework but is flexible and integrates well with existing solution. We have an existing solution that exposes a webservice using Axis 1.4 deployed as web applications. This is a common solution. We use contract first so we have Axis generated source code from an existing wsdl file. Then we show how we introduce Spring and Camel to integrate with Axis. This tutorial uses the following frameworks:
Setting up the project to run AxisThis first part is about getting the project up to speed with Axis. We are not touching Camel or Spring at this time. Maven 2Axis dependencies is available for maven 2 so we configure our pom.xml as:
<dependency>
<groupId>org.apache.axis</groupId>
<artifactId>axis</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>org.apache.axis</groupId>
<artifactId>axis-jaxrpc</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>org.apache.axis</groupId>
<artifactId>axis-saaj</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>axis</groupId>
<artifactId>axis-wsdl4j</artifactId>
<version>1.5.1</version>
</dependency>
<dependency>
<groupId>commons-discovery</groupId>
<artifactId>commons-discovery</artifactId>
<version>0.4</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.14</version>
</dependency>
Then we need to configure maven to use Java 1.5 and the Axis maven plugin that generates the source code based on the wsdl file: <!-- to compile with 1.5 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.5</source> <target>1.5</target> </configuration> </plugin> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>axistools-maven-plugin</artifactId> <configuration> <sourceDirectory>src/main/resources/</sourceDirectory> <packageSpace>com.mycompany.myschema</packageSpace> <testCases>false</testCases> <serverSide>true</serverSide> <subPackageByFileName>false</subPackageByFileName> </configuration> <executions> <execution> <goals> <goal>wsdl2java</goal> </goals> </execution> </executions> </plugin> wsdlWe use the same .wsdl file as the Tutorial-Example-ReportIncident and copy it to src/main/webapp/WEB-INF/wsdl <?xml version="1.0" encoding="ISO-8859-1"?> <wsdl:definitions xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="http://reportincident.example.camel.apache.org" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://reportincident.example.camel.apache.org"> <!-- Type definitions for input- and output parameters for webservice --> <wsdl:types> <xs:schema targetNamespace="http://reportincident.example.camel.apache.org"> <xs:element name="inputReportIncident"> <xs:complexType> <xs:sequence> <xs:element type="xs:string" name="incidentId"/> <xs:element type="xs:string" name="incidentDate"/> <xs:element type="xs:string" name="givenName"/> <xs:element type="xs:string" name="familyName"/> <xs:element type="xs:string" name="summary"/> <xs:element type="xs:string" name="details"/> <xs:element type="xs:string" name="email"/> <xs:element type="xs:string" name="phone"/> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="outputReportIncident"> <xs:complexType> <xs:sequence> <xs:element type="xs:string" name="code"/> </xs:sequence> </xs:complexType> </xs:element> </xs:schema> </wsdl:types> <!-- Message definitions for input and output --> <wsdl:message name="inputReportIncident"> <wsdl:part name="parameters" element="tns:inputReportIncident"/> </wsdl:message> <wsdl:message name="outputReportIncident"> <wsdl:part name="parameters" element="tns:outputReportIncident"/> </wsdl:message> <!-- Port (interface) definitions --> <wsdl:portType name="ReportIncidentEndpoint"> <wsdl:operation name="ReportIncident"> <wsdl:input message="tns:inputReportIncident"/> <wsdl:output message="tns:outputReportIncident"/> </wsdl:operation> </wsdl:portType> <!-- Port bindings to transports and encoding - HTTP, document literal encoding is used --> <wsdl:binding name="ReportIncidentBinding" type="tns:ReportIncidentEndpoint"> <soap:binding transport="http://schemas.xmlsoap.org/soap/http"/> <wsdl:operation name="ReportIncident"> <soap:operation soapAction="http://reportincident.example.camel.apache.org/ReportIncident" style="document"/> <wsdl:input> <soap:body parts="parameters" use="literal"/> </wsdl:input> <wsdl:output> <soap:body parts="parameters" use="literal"/> </wsdl:output> </wsdl:operation> </wsdl:binding> <!-- Service definition --> <wsdl:service name="ReportIncidentService"> <wsdl:port name="ReportIncidentPort" binding="tns:ReportIncidentBinding"> <soap:address location="http://reportincident.example.camel.apache.org"/> </wsdl:port> </wsdl:service> </wsdl:definitions> Configuring AxisOkay we are now setup for the contract first development and can generate the source file. For now we are still only using standard Axis and not Spring nor Camel. We still need to setup Axis as a web application so we configure the web.xml in src/main/webapp/WEB-INF/web.xml as:
<servlet>
<servlet-name>axis</servlet-name>
<servlet-class>org.apache.axis.transport.http.AxisServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>axis</servlet-name>
<url-pattern>/services/*</url-pattern>
</servlet-mapping>
The web.xml just registers Axis servlet that is handling the incoming web requests to its servlet mapping. We still need to configure Axis itself and this is done using its special configuration file server-config.wsdd. We nearly get this file for free if we let Axis generate the source code so we run the maven goal: mvn axistools:wsdl2java The tool will generate the source code based on the wsdl and save the files to the following folder: .\target\generated-sources\axistools\wsdl2java\org\apache\camel\example\reportincident deploy.wsdd InputReportIncident.java OutputReportIncident.java ReportIncidentBindingImpl.java ReportIncidentBindingStub.java ReportIncidentService_PortType.java ReportIncidentService_Service.java ReportIncidentService_ServiceLocator.java undeploy.wsdd This is standard Axis and so far no Camel or Spring has been touched. To implement our webservice we will add our code, so we create a new class AxisReportIncidentService that implements the port type interface where we can implement our code logic what happens when the webservice is invoked. package org.apache.camel.example.axis; import org.apache.camel.example.reportincident.InputReportIncident; import org.apache.camel.example.reportincident.OutputReportIncident; import org.apache.camel.example.reportincident.ReportIncidentService_PortType; import java.rmi.RemoteException; /** * Axis webservice */ public class AxisReportIncidentService implements ReportIncidentService_PortType { public OutputReportIncident reportIncident(InputReportIncident parameters) throws RemoteException { System.out.println("Hello AxisReportIncidentService is called from " + parameters.getGivenName()); OutputReportIncident out = new OutputReportIncident(); out.setCode("OK"); return out; } } Now we need to configure Axis itself and this is done using its server-config.wsdd file. We nearly get this for for free from the auto generated code, we copy the stuff from deploy.wsdd and made a few modifications: <?xml version="1.0" encoding="UTF-8"?> <deployment xmlns="http://xml.apache.org/axis/wsdd/" xmlns:java="http://xml.apache.org/axis/wsdd/providers/java"> <!-- global configuration --> <globalConfiguration> <parameter name="sendXsiTypes" value="true"/> <parameter name="sendMultiRefs" value="true"/> <parameter name="sendXMLDeclaration" value="true"/> <parameter name="axis.sendMinimizedElements" value="true"/> </globalConfiguration> <handler name="URLMapper" type="java:org.apache.axis.handlers.http.URLMapper"/> <!-- this service is from deploy.wsdd --> <service name="ReportIncidentPort" provider="java:RPC" style="document" use="literal"> <parameter name="wsdlTargetNamespace" value="http://reportincident.example.camel.apache.org"/> <parameter name="wsdlServiceElement" value="ReportIncidentService"/> <parameter name="schemaUnqualified" value="http://reportincident.example.camel.apache.org"/> <parameter name="wsdlServicePort" value="ReportIncidentPort"/> <parameter name="className" value="org.apache.camel.example.reportincident.ReportIncidentBindingImpl"/> <parameter name="wsdlPortType" value="ReportIncidentService"/> <parameter name="typeMappingVersion" value="1.2"/> <operation name="reportIncident" qname="ReportIncident" returnQName="retNS:outputReportIncident" xmlns:retNS="http://reportincident.example.camel.apache.org" returnType="rtns:>outputReportIncident" xmlns:rtns="http://reportincident.example.camel.apache.org" soapAction="http://reportincident.example.camel.apache.org/ReportIncident" > <parameter qname="pns:inputReportIncident" xmlns:pns="http://reportincident.example.camel.apache.org" type="tns:>inputReportIncident" xmlns:tns="http://reportincident.example.camel.apache.org"/> </operation> <parameter name="allowedMethods" value="reportIncident"/> <typeMapping xmlns:ns="http://reportincident.example.camel.apache.org" qname="ns:>outputReportIncident" type="java:org.apache.camel.example.reportincident.OutputReportIncident" serializer="org.apache.axis.encoding.ser.BeanSerializerFactory" deserializer="org.apache.axis.encoding.ser.BeanDeserializerFactory" encodingStyle="" /> <typeMapping xmlns:ns="http://reportincident.example.camel.apache.org" qname="ns:>inputReportIncident" type="java:org.apache.camel.example.reportincident.InputReportIncident" serializer="org.apache.axis.encoding.ser.BeanSerializerFactory" deserializer="org.apache.axis.encoding.ser.BeanDeserializerFactory" encodingStyle="" /> </service> <!-- part of Axis configuration --> <transport name="http"> <requestFlow> <handler type="URLMapper"/> <handler type="java:org.apache.axis.handlers.http.HTTPAuthHandler"/> </requestFlow> </transport> </deployment> The globalConfiguration and transport is not in the deploy.wsdd file so you gotta write that yourself. The service is a 100% copy from deploy.wsdd. Axis has more configuration to it than shown here, but then you should check the Axis documentation. What we need to do now is important, as we need to modify the above configuration to use our webservice class than the default one, so we change the classname parameter to our class AxisReportIncidentService:
<parameter name="className" value="org.apache.camel.example.axis.AxisReportIncidentService"/>
Running the ExampleNow we are ready to run our example for the first time, so we use Jetty as the quick web container using its maven command: mvn jetty:run Then we can hit the web browser and enter this URL: http://localhost:8080/camel-example-axis/services and you should see the famous Axis start page with the text And now... Some Services. Clicking on the .wsdl link shows the wsdl file, but what. It's an auto generated one and not our original .wsdl file. So we need to fix this ASAP and this is done by configuring Axis in the server-config.wsdd file: <service name="ReportIncidentPort" provider="java:RPC" style="document" use="literal"> <wsdlFile>/WEB-INF/wsdl/report_incident.wsdl</wsdlFile> ... We do this by adding the wsdlFile tag in the service element where we can point to the real .wsdl file. Integrating SpringFirst we need to add its dependencies to the pom.xml.
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>2.5.5</version>
</dependency>
Spring is integrated just as it would like to, we add its listener to the web.xml and a context parameter to be able to configure precisely what spring xml files to use:
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
classpath:axis-example-context.xml
</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
Next is to add a plain spring XML file named axis-example-context.xml in the src/main/resources folder. <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> </beans> The spring XML file is currently empty. We hit jetty again with mvn jetty:run just to make sure Spring was setup correctly. Using SpringWe would like to be able to get hold of the Spring ApplicationContext from our webservice so we can get access to the glory spring, but how do we do this? And our webservice class AxisReportIncidentService is created and managed by Axis we want to let Spring do this. So we have two problems. We solve these problems by creating a delegate class that Axis creates, and this delegate class gets hold on Spring and then gets our real webservice as a spring bean and invoke the service. First we create a new class that is 100% independent from Axis and just a plain POJO. This is our real service. package org.apache.camel.example.axis; import org.apache.camel.example.reportincident.InputReportIncident; import org.apache.camel.example.reportincident.OutputReportIncident; /** * Our real service that is not tied to Axis */ public class ReportIncidentService { public OutputReportIncident reportIncident(InputReportIncident parameters) { System.out.println("Hello ReportIncidentService is called from " + parameters.getGivenName()); OutputReportIncident out = new OutputReportIncident(); out.setCode("OK"); return out; } } So now we need to get from AxisReportIncidentService to this one ReportIncidentService using Spring. Well first of all we add our real service to spring XML configuration file so Spring can handle its lifecycle: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <bean id="incidentservice" class="org.apache.camel.example.axis.ReportIncidentService"/> </beans> And then we need to modify AxisReportIncidentService to use Spring to lookup the spring bean id="incidentservice" and delegate the call. We do this by extending the spring class org.springframework.remoting.jaxrpc.ServletEndpointSupport so the refactored code is: package org.apache.camel.example.axis; import org.apache.camel.example.reportincident.InputReportIncident; import org.apache.camel.example.reportincident.OutputReportIncident; import org.apache.camel.example.reportincident.ReportIncidentService_PortType; import org.springframework.remoting.jaxrpc.ServletEndpointSupport; import java.rmi.RemoteException; /** * Axis webservice */ public class AxisReportIncidentService extends ServletEndpointSupport implements ReportIncidentService_PortType { public OutputReportIncident reportIncident(InputReportIncident parameters) throws RemoteException { // get hold of the spring bean from the application context ReportIncidentService service = (ReportIncidentService) getApplicationContext().getBean("incidentservice"); // delegate to the real service return service.reportIncident(parameters); } } To see if everything is okay we run mvn jetty:run. In the code above we get hold of our service at each request by looking up in the application context. However Spring also supports an init method where we can do this once. So we change the code to: public class AxisReportIncidentService extends ServletEndpointSupport implements ReportIncidentService_PortType { private ReportIncidentService service; @Override protected void onInit() throws ServiceException { // get hold of the spring bean from the application context service = (ReportIncidentService) getApplicationContext().getBean("incidentservice"); } public OutputReportIncident reportIncident(InputReportIncident parameters) throws RemoteException { // delegate to the real service return service.reportIncident(parameters); } } So now we have integrated Axis with Spring and we are ready for Camel. Integrating CamelAgain the first step is to add the dependencies to the maven pom.xml file:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
<version>1.5.0</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-spring</artifactId>
<version>1.5.0</version>
</dependency>
Now that we have integrated with Spring then we easily integrate with Camel as Camel works well with Spring.
We choose to integrate Camel in the Spring XML file so we add the camel namespace and the schema location: xmlns:camel="http://activemq.apache.org/camel/schema/spring" http://activemq.apache.org/camel/schema/spring http://activemq.apache.org/camel/schema/spring/camel-spring.xsd" CamelContextCamelContext is the heart of Camel its where all the routes, endpoints, components, etc. is registered. So we setup a CamelContext and the spring XML files looks like: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://activemq.apache.org/camel/schema/spring" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://activemq.apache.org/camel/schema/spring http://activemq.apache.org/camel/schema/spring/camel-spring.xsd"> <bean id="incidentservice" class="org.apache.camel.example.axis.ReportIncidentService"/> <camel:camelContext id="camel"> <!-- TODO: Here we can add Camel stuff --> </camel:camelContext> </beans> Store a file backupWe want to store the web service request as a file before we return a response. To do this we want to send the file content as a message to an endpoint that produces the file. So we need to do two steps:
The endpoint is configured in spring XML so we just add it as:
<camel:camelContext id="camelContext">
<!-- endpoint named backup that is configued as a file component -->
<camel:endpoint id="backup" uri="file://target?append=false"/>
</camel:camelContext>
In the CamelContext we have defined our endpoint with the id backup and configured it use the URL notation that we know from the internet. Its a file scheme that accepts a context and some options. The contest is target and its the folder to store the file. The option is just as the internet with ? and & for subsequent options. We configure it to not append, meaning than any existing file will be overwritten. See the File component for options and how to use the camel file endpoint. Next up is to be able to send a message to this endpoint. The easiest way is to use a ProducerTemplate. A ProducerTemplate is inspired by Spring template pattern with for instance JmsTemplate or JdbcTemplate in mind. The template that all the grunt work and exposes a simple interface to the end-user where he/she can set the payload to send. Then the template will do proper resource handling and all related issues in that regard. But how do we get hold of such a template? Well the CamelContext is able to provide one. This is done by configuring the template on the camel context in the spring XML as:
<camel:camelContext id="camelContext">
<!-- producer template exposed with this id -->
<camel:template id="camelTemplate"/>
<!-- endpoint named backup that is configued as a file component -->
<camel:endpoint id="backup" uri="file://target?append=false"/>
</camel:camelContext>
Then we can expose a ProducerTemplate property on our service with a setter in the Java code as: public class ReportIncidentService { private ProducerTemplate template; public void setTemplate(ProducerTemplate template) { this.template = template; } And then let Spring handle the dependency inject as below:
<bean id="incidentservice" class="org.apache.camel.example.axis.ReportIncidentService">
<!-- set the producer template to use from the camel context below -->
<property name="template" ref="camelTemplate"/>
</bean>
Now we are ready to use the producer template in our service to send the payload to the endpoint. The template has many sendXXX methods for this purpose. But before we send the payload to the file endpoint we must also specify what filename to store the file as. This is done by sending meta data with the payload. In Camel metadata is sent as headers. Headers is just a plain Map<String, Object>. So if we needed to send several metadata then we could construct an ordinary HashMap and put the values in there. But as we just need to send one header with the filename Camel has a convenient send method sendBodyAndHeader so we choose this one.
public OutputReportIncident reportIncident(InputReportIncident parameters) {
System.out.println("Hello ReportIncidentService is called from " + parameters.getGivenName());
String data = parameters.getDetails();
// store the data as a file
String filename = parameters.getIncidentId() + ".txt";
// send the data to the endpoint and the header contains what filename it should be stored as
template.sendBodyAndHeader("backup", data, "org.apache.camel.file.name", filename);
OutputReportIncident out = new OutputReportIncident();
out.setCode("OK");
return out;
}
The template in the code above uses 4 parameters:
Running the exampleWe start our integration with maven using mvn jetty:run. Then we open a browser and hit http://localhost:8080. Jetty is so smart that it display a frontpage with links to the deployed application so just hit the link and you get our application. Now we hit append /services to the URL to access the Axis frontpage. The URL should be http://localhost:8080/camel-example-axis/services. You can then test it using a web service test tools such as SoapUI. 2008-09-06 15:01:41.718::INFO: Started SelectChannelConnector @ 0.0.0.0:8080 [INFO] Started Jetty Server Hello ReportIncidentService is called from Ibsen And there should be a file in the target subfolder. dir target /b 123.txt Unit TestingWe would like to be able to unit test our ReportIncidentService class. So we add junit to the maven dependency:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.2</version>
<scope>test</scope>
</dependency>
And then we create a plain junit testcase for our service class. package org.apache.camel.example.axis; import junit.framework.TestCase; import org.apache.camel.example.reportincident.InputReportIncident; import org.apache.camel.example.reportincident.OutputReportIncident; /** * Unit test of service */ public class ReportIncidentServiceTest extends TestCase { public void testIncident() { ReportIncidentService service = new ReportIncidentService(); InputReportIncident input = createDummyIncident(); OutputReportIncident output = service.reportIncident(input); assertEquals("OK", output.getCode()); } protected InputReportIncident createDummyIncident() { InputReportIncident input = new InputReportIncident(); input.setEmail("davsclaus@apache.org"); input.setIncidentId("12345678"); input.setIncidentDate("2008-07-13"); input.setPhone("+45 2962 7576"); input.setSummary("Failed operation"); input.setDetails("The wrong foot was operated."); input.setFamilyName("Ibsen"); input.setGivenName("Claus"); return input; } } Then we can run the test with maven using: mvn test. But we will get a failure: Running org.apache.camel.example.axis.ReportIncidentServiceTest Hello ReportIncidentService is called from Claus Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.235 sec <<< FAILURE! Results : Tests in error: testIncident(org.apache.camel.example.axis.ReportIncidentServiceTest) Tests run: 1, Failures: 0, Errors: 1, Skipped: 0 What is the problem? Well our service uses a CamelProducer (the template) to send a message to the file endpoint so the message will be stored in a file. What we need is to get hold of such a producer and inject it on our service, by calling the setter. Since Camel is very light weight and embedable we are able to create a CamelContext and add the endpoint in our unit test code directly. We do this to show how this is possible:
private CamelContext context;
@Override
protected void setUp() throws Exception {
super.setUp();
// CamelContext is just created like this
context = new DefaultCamelContext();
// then we can create our endpoint and set the options
FileEndpoint endpoint = new FileEndpoint();
// the endpoint must have the camel context set also
endpoint.setCamelContext(context);
// our output folder
endpoint.setFile(new File("target"));
// and the option not to append
endpoint.setAppend(false);
// then we add the endpoint just in java code just as the spring XML, we register it with the "backup" id.
context.addSingletonEndpoint("backup", endpoint);
// finally we need to start the context so Camel is ready to rock
context.start();
}
@Override
protected void tearDown() throws Exception {
super.tearDown();
// and we are nice boys so we stop it to allow resources to clean up
context.stop();
}
So now we are ready to set the ProducerTemplate on our service, and we get a hold of that baby from the CamelContext as:
public void testIncident() {
ReportIncidentService service = new ReportIncidentService();
// get a producer template from the camel context
ProducerTemplate template = context.createProducerTemplate();
// inject it on our service using the setter
service.setTemplate(template);
InputReportIncident input = createDummyIncident();
OutputReportIncident output = service.reportIncident(input);
assertEquals("OK", output.getCode());
}
And this time when we run the unit test its a success: Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 We would like to test that the file exists so we add these two lines to our test method:
// should generate a file also
File file = new File("target/" + input.getIncidentId() + ".txt");
assertTrue("File should exists", file.exists());
Smarter Unit Testing with SpringThe unit test above requires us to assemble the Camel pieces manually in java code. What if we would like our unit test to use our spring configuration file axis-example-context.xml where we already have setup the endpoint. And of course we would like to test using this configuration file as this is the real file we will use. Well hey presto the xml file is a spring ApplicationContext file and spring is able to load it, so we go the spring path for unit testing. First we add the spring-test jar to our maven dependency:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<scope>test</scope>
</dependency>
And then we refactor our unit test to be a standard spring unit class. What we need to do is to extend AbstractJUnit38SpringContextTests instead of TestCase in our unit test. Since Spring 2.5 embraces annotations we will use one as well to instruct what our xml configuration file is located: @ContextConfiguration(locations = "classpath:axis-example-context.xml") public class ReportIncidentServiceTest extends AbstractJUnit38SpringContextTests { What we must remember to add is the classpath: prefix as our xml file is located in src/main/resources. If we omit the prefix then Spring will by default try to locate the xml file in the current package and that is org.apache.camel.example.axis. If the xml file is located outside the classpath you can use file: prefix instead. So with these two modifications we can get rid of all the setup and teardown code we had before and now we will test our real configuration. The last change is to get hold of the producer template and now we can just refer to the bean id it has in the spring xml file:
<!-- producer template exposed with this id -->
<camel:template id="camelTemplate"/>
So we get hold of it by just getting it from the spring ApplicationContext as all spring users is used to do:
// get a producer template from the the spring context
ProducerTemplate template = (ProducerTemplate) applicationContext.getBean("camelTemplate");
// inject it on our service using the setter
service.setTemplate(template);
Now our unit test is much better, and a real power of Camel is that is fits nicely with Spring and you can use standard Spring'ish unit test to test your Camel applications as well. Unit Test calling WebServiceWhat if you would like to execute a unit test where you send a webservice request to the AxisReportIncidentService how do we unit test this one? Well first of all the code is merely just a delegate to our real service that we have just tested, but nevertheless its a good question and we would like to know how. Well the answer is that we can exploit that fact that Jetty is also a slim web container that can be embedded anywhere just as Camel can. So we add this to our pom.xml:
<dependency>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty</artifactId>
<version>${jetty-version}</version>
<scope>test</scope>
</dependency>
Then we can create a new class AxisReportIncidentServiceTest to unit test with Jetty. The code to setup Jetty is shown below with code comments: public class AxisReportIncidentServiceTest extends TestCase { private Server server; private void startJetty() throws Exception { // create an embedded Jetty server server = new Server(); // add a listener on port 8080 on localhost (127.0.0.1) Connector connector = new SelectChannelConnector(); connector.setPort(8080); connector.setHost("127.0.0.1"); server.addConnector(connector); // add our web context path WebAppContext wac = new WebAppContext(); wac.setContextPath("/unittest"); // set the location of the exploded webapp where WEB-INF is located // this is a nice feature of Jetty where we can point to src/main/webapp wac.setWar("./src/main/webapp"); server.setHandler(wac); // then start Jetty server.setStopAtShutdown(true); server.start(); } @Override protected void setUp() throws Exception { super.setUp(); startJetty(); } @Override protected void tearDown() throws Exception { super.tearDown(); server.stop(); } } Now we just need to send the incident as a webservice request using Axis. So we add the following code:
public void testReportIncidentWithAxis() throws Exception {
// the url to the axis webservice exposed by jetty
URL url = new URL("http://localhost:8080/unittest/services/ReportIncidentPort");
// Axis stuff to get the port where we can send the webservice request
ReportIncidentService_ServiceLocator locator = new ReportIncidentService_ServiceLocator();
ReportIncidentService_PortType port = locator.getReportIncidentPort(url);
// create input to send
InputReportIncident input = createDummyIncident();
// send the webservice and get the response
OutputReportIncident output = port.reportIncident(input);
assertEquals("OK", output.getCode());
// should generate a file also
File file = new File("target/" + input.getIncidentId() + ".txt");
assertTrue("File should exists", file.exists());
}
protected InputReportIncident createDummyIncident() {
InputReportIncident input = new InputReportIncident();
input.setEmail("davsclaus@apache.org");
input.setIncidentId("12345678");
input.setIncidentDate("2008-07-13");
input.setPhone("+45 2962 7576");
input.setSummary("Failed operation");
input.setDetails("The wrong foot was operated.");
input.setFamilyName("Ibsen");
input.setGivenName("Claus");
return input;
}
And now we have an unittest that sends a webservice request using good old Axis. AnnotationsBoth Camel and Spring has annotations that can be used to configure and wire trivial settings more elegantly. Camel has the endpoint annotation @EndpointInjected that is just what we need. With this annotation we can inject the endpoint into our service. The annotation takes either a name or uri parameter. The name is the bean id in the Registry. The uri is the URI configuration for the endpoint. Using this you can actually inject an endpoint that you have not defined in the camel context. As we have defined our endpoint with the id backup we use the name parameter.
@EndpointInject(name = "backup")
private ProducerTemplate template;
Camel is smart as @EndpointInjected supports different kinds of object types. We like the ProducerTemplate so we just keep it as it is.
<bean id="incidentservice" class="org.apache.camel.example.axis.ReportIncidentService"/>
Running the unit test with mvn test reveals that it works nicely. And since we use the @EndpointInjected that refers to the endpoint with the id backup directly we can loose the template tag in the xml, so its shorter:
<bean id="incidentservice" class="org.apache.camel.example.axis.ReportIncidentService"/>
<camel:camelContext id="camelContext">
<!-- producer template exposed with this id -->
<camel:template id="camelTemplate"/>
<!-- endpoint named backup that is configued as a file component -->
<camel:endpoint id="backup" uri="file://target?append=false"/>
</camel:camelContext>
And the final touch we can do is that since the endpoint is injected with concrete endpoint to use we can remove the "backup" name parameter when we send the message. So we change from:
// send the data to the endpoint and the header contains what filename it should be stored as
template.sendBodyAndHeader("backup", data, "org.apache.camel.file.name", filename);
To without the name:
// send the data to the endpoint and the header contains what filename it should be stored as
template.sendBodyAndHeader(data, "org.apache.camel.file.name", filename);
Then we avoid to duplicate the name and if we rename the endpoint name then we don't forget to change it in the code also. The EndThis tutorial hasn't really touched the one of the key concept of Camel as a powerful routing and mediation framework. But we wanted to demonstrate its flexibility and that it integrates well with even older frameworks such as Apache Axis 1.4. Check out the other tutorials on Camel and the other examples. Note that the code shown here also applies to Camel 1.4 so actually you can get started right away with the released version of Camel. As this time of writing Camel 1.5 is work in progress. See AlsoTutorial on using Camel in a Web ApplicationCamel has been designed to work great with the Spring framework; so if you are already a Spring user you can think of Camel as just a framework for adding to your Spring XML files. So you can follow the usual Spring approach to working with web applications; namely to add the standard Spring hook to load a /WEB-INF/applicationContext.xml file. In that file you can include your usual Camel XML configuration. Step1: Edit your web.xmlTo enable spring add a context loader listener to your /WEB-INF/web.xml file <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> </web-app> This will cause Spring to boot up and look for the /WEB-INF/applicationContext.xml file. Step 2: Create a /WEB-INF/applicationContext.xml fileNow you just need to create your Spring XML file and add your camel routes or configuration. For example <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:foo"/> <to uri="mock:results"/> </route> </camelContext> </beans> Then boot up your web application and you're good to go! Hints and TipsIf you use Maven to build your application your directory tree will look like this... src/main/webapp/WEB-INF web.xml applicationContext.xml You should update your Maven pom.xml to enable WAR packaging/naming like this... <project> ... <packaging>war</packaging> ... <build> <finalName>[desired WAR file name]</finalName> ... </build> To enable more rapid development we highly recommend the jetty:run maven plugin. Please refer to the help for more information on using jetty:run - but briefly if you add the following to your pom.xml <build> <plugins> <plugin> <groupId>org.mortbay.jetty</groupId> <artifactId>maven-jetty-plugin</artifactId> <configuration> <webAppConfig> <contextPath>/</contextPath> </webAppConfig> <scanIntervalSeconds>10</scanIntervalSeconds> </configuration> </plugin> </plugins> </build> Then you can run your web application as follows mvn jetty:run Then Jetty will also monitor your target/classes directory and your src/main/webapp directory so that if you modify your spring XML, your web.xml or your java code the web application will be restarted, re-creating your Camel routes. If your unit tests take a while to run, you could miss them out when running your web application via
mvn -Dtest=false jetty:run
Tutorial Business Partners
Background and IntroductionBusiness BackgroundSo there's a company, which we'll call Acme. Acme sells widgets, in a fairly unusual way. Their customers are responsible for telling Acme what they purchased. The customer enters into their own systems (ERP or whatever) which widgets they bought from Acme. Then at some point, their systems emit a record of the sale which needs to go to Acme so Acme can bill them for it. Obviously, everyone wants this to be as automated as possible, so there needs to be integration between the customer's system and Acme. Sadly, Acme's sales people are, technically speaking, doormats. They tell all their prospects, "you can send us the data in whatever format, using whatever protocols, whatever. You just can't change once it's up and running." The result is pretty much what you'd expect. Taking a random sample of 3 customers:
Now on the Acme side, all this has to be converted to a canonical XML format and submitted to the Acme accounting system via JMS. Then the Acme accounting system does its stuff and sends an XML reply via JMS, with a summary of what it processed (e.g. 3 line items accepted, line item #2 in error, total invoice $123.45). Finally, that data needs to be formatted into an e-mail, and sent to a contact at the customer in question ("Dear Joyce, we received an invoice on 1/2/08. We accepted 3 line items totaling $123.45, though there was an error with line items #2 [invalid quantity ordered]. Thank you for your business. Love, Acme."). So it turns out Camel can handle all this:
Tutorial BackgroundThis tutorial will cover all that, plus setting up tests along the way. Before starting, you should be familiar with:
You'll learn:
You may choose to treat this as a hands-on tutorial, and work through building the code and configuration files yourself. Each of the sections gives detailed descriptions of the steps that need to be taken to get the components and routes working in Camel, and takes you through tests to make sure they are working as expected. But each section also links to working copies of the source and configuration files, so if you don't want the hands-on approach, you can simply review and/or download the finished files. High-Level DiagramHere's more or less what the integration process looks like. First, the input from the customers to Acme:
And then, the output from Acme to the customers:
Tutorial TasksTo get through this scenario, we're going to break it down into smaller pieces, implement and test those, and then try to assemble the big scenario and test that. Here's what we'll try to accomplish:
Let's Get Started!Step 1: Initial Maven buildWe'll use Maven for this project as there will eventually be quite a few dependencies and it's nice to have Maven handle them for us. You should have a current version of Maven (e.g. 2.0.9) installed. You can start with a pretty empty project directory and a Maven POM file, or use a simple JAR archetype to create one. Here's a sample POM. We've added a dependency on camel-core, and set the compile version to 1.5 (so we can use annotations): pom.xml <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0"> <modelVersion>4.0.0</modelVersion> <groupId>org.apache.camel.tutorial</groupId> <artifactId>business-partners</artifactId> <version>1.0-SNAPSHOT</version> <name>Camel Business Partners Tutorial</name> <dependencies> <dependency> <artifactId>camel-core</artifactId> <groupId>org.apache.camel</groupId> <version>1.4.0</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.5</source> <target>1.5</target> </configuration> </plugin> </plugins> </build> </project> Step 2: Get Sample FilesYou can make up your own if you like, but here are the "off the shelf" ones. You can save yourself some time by downloading these to src/test/resources in your Maven project.
If you look at these files, you'll see that the different input formats use different field names and/or ordering, because of course the sales guys were totally OK with that. Sigh. Step 3: XSD and JAXB Beans for the Canonical XML FormatHere's the sample of the canonical XML file: <?xml version="1.0" encoding="UTF-8"?> <invoice xmlns="http://activemq.apache.org/camel/tutorial/partners/invoice"> <partner-id>2</partner-id> <date-received>9/12/2008</date-received> <line-item> <product-id>134</product-id> <description>A widget</description> <quantity>3</quantity> <item-price>10.45</item-price> <order-date>6/5/2008</order-date> </line-item> <!-- // more line-item elements here --> <order-total>218.82</order-total> </invoice> If you're ambitions, you can write your own XSD (XML Schema) for files that look like this, and save it to src/main/xsd. Solution: If not, you can download mine, and save that to save it to src/main/xsd. Generating JAXB BeansDown the road we'll want to deal with the XML as Java POJOs. We'll take a moment now to set up those XML binding POJOs. So we'll update the Maven POM to generate JAXB beans from the XSD file. We need a dependency: <dependency> <artifactId>camel-jaxb</artifactId> <groupId>org.apache.camel</groupId> <version>1.4.0</version> </dependency> And a plugin configured: <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>jaxb2-maven-plugin</artifactId> <executions> <execution> <goals> <goal>xjc</goal> </goals> </execution> </executions> </plugin> That should do it (it automatically looks for XML Schemas in src/main/xsd to generate beans for). Run mvn install and it should emit the beans into target/generated-sources/jaxb. Your IDE should see them there, though you may need to update the project to reflect the new settings in the Maven POM. Step 4: Initial Work on Customer 1 Input (XML over FTP)To get a start on Customer 1, we'll create an XSLT template to convert the Customer 1 sample file into the canonical XML format, write a small Camel route to test it, and build that into a unit test. If we get through this, we can be pretty sure that the XSLT template is valid and can be run safely in Camel. Create an XSLT templateStart with the Customer 1 sample input. You want to create an XSLT template to generate XML like the canonical XML sample above – an invoice element with line-item elements (one per item in the original XML document). If you're especially clever, you can populate the current date and order total elements too. Solution: My sample XSLT template isn't that smart, but it'll get you going if you don't want to write one of your own. Create a unit testHere's where we get to some meaty Camel work. We need to:
The easiest way to do this is to set up a Spring context that defines the Camel stuff, and then use a base unit test class from Spring that knows how to load a Spring context to run tests against. So, the procedure is: Set Up a Skeletal Camel/Spring Unit Test
Test it by running mvn install and make sure there are no build errors. So far it doesn't test much; just that your project and test and source files are all organized correctly, and the one empty test method completes successfully. Solution: Your test class might look something like this:
Flesh Out the Unit TestSo now we're going to write a Camel route that applies the XSLT to the sample Customer 1 input file, and makes sure that some XML output comes out:
Solution: Your finished test might look something like this:
Step 5: Initial Work on Customer 2 Input (CSV over HTTP)To get a start on Customer 2, we'll create a POJO to convert the Customer 2 sample CSV data into the JAXB POJOs representing the canonical XML format, write a small Camel route to test it, and build that into a unit test. If we get through this, we can be pretty sure that the CSV conversion and JAXB handling is valid and can be run safely in Camel. Create a CSV-handling POJOTo begin with, CSV is a known data format in Camel. Camel can convert a CSV file to a List (representing rows in the CSV) of Lists (representing cells in the row) of Strings (the data for each cell). That means our POJO can just assume the data coming in is of type List<List<String>>, and we can declare a method with that as the argument. Looking at the JAXB code in target/generated-sources/jaxb, it looks like an Invoice object represents the whole document, with a nested list of LineItemType objects for the line items. Therefore our POJO method will return an Invoice (a document in the canonical XML format). So to implement the CSV-to-JAXB POJO, we need to do something like this:
Solution: Here's an example of what the CSVConverterBean might look like. Create a unit testStart with a simple test class and test Spring context like last time, perhaps based on the name CSVInputTest: CSVInputTest.java /** * A test class the ensure we can convert Partner 2 CSV input files to the * canonical XML output format, using JAXB POJOs. */ @ContextConfiguration(locations = "/CSVInputTest-context.xml") public class CSVInputTest extends AbstractJUnit38SpringContextTests { @Autowired protected CamelContext camelContext; protected ProducerTemplate<Exchange> template; protected void setUp() throws Exception { super.setUp(); template = camelContext.createProducerTemplate(); } public void testCSVConversion() { // TODO } } CSVInputTest-context.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://activemq.apache.org/camel/schema/spring http://activemq.apache.org/camel/schema/spring/camel-spring-1.4.0.xsd"> <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring"> <!-- TODO --> </camelContext> </beans> Now the meaty part is to flesh out the test class and write the Camel routes.
Solution: Your finished test might look something like this:
Step 6: Initial Work on Customer 3 Input (Excel over e-mail)To get a start on Customer 3, we'll create a POJO to convert the Customer 3 sample Excel data into the JAXB POJOs representing the canonical XML format, write a small Camel route to test it, and build that into a unit test. If we get through this, we can be pretty sure that the Excel conversion and JAXB handling is valid and can be run safely in Camel. Create an Excel-handling POJOCamel does not have a data format handler for Excel by default. We have two options – create an Excel DataFormat (so Camel can convert Excel spreadsheets to something like the CSV List<List<String>> automatically), or create a POJO that can translate Excel data manually. For now, the second approach is easier (if we go the DataFormat route, we need code to both read and write Excel files, whereas otherwise read-only will do). So, we need a POJO with a method that takes something like an InputStream or byte[] as an argument, and returns in Invoice as before. The process should look something like this:
Solution: Here's an example of what the ExcelConverterBean might look like. Create a unit testThe unit tests should be pretty familiar now. The test class and context for the Excel bean should be quite similar to the CSV bean.
Solution: Your finished test might look something like this:
Step 7: Put this all together into Camel routes for the Customer InputWith all the data type conversions working, the next step is to write the real routes that listen for HTTP, FTP, or e-mail input, and write the final XML output to an ActiveMQ queue. Along the way these routes will use the data conversions we've developed above. So we'll create 3 routes to start with, as shown in the diagram back at the beginning:
... Step 8: Create a unit test for the Customer Input RoutesLanguages Supported AppendixTo support flexible and powerful Enterprise Integration Patterns Camel supports various Languages to create an Expression or Predicate within either the Routing Domain Specific Language or the Xml Configuration. The following languages are supported Bean LanguageThe purpose of the Bean Language is to be able to implement an Expression or Predicate using a simple method on a bean. So the idea is you specify a bean name which will then be resolved in the Registry such as the Spring ApplicationContext then a method is invoked to evaluate the Expression or Predicate. If no method name is provided then one is attempted to be chosen using the rules for Bean Binding; using the type of the message body and using any annotations on the bean methods. The Bean Binding rules are used to bind the Message Exchange to the method parameters; so you can annotate the bean to extract headers or other expressions such as XPath or XQuery from the message. Using Bean Expressions from the Java DSLfrom("activemq:topic:OrdersTopic"). filter().method("myBean", "isGoldCustomer"). to("activemq:BigSpendersQueue"); Using Bean Expressions from XML<route> <from uri="activemq:topic:OrdersTopic"/> <filter> <method bean="myBean" method="isGoldCustomer"/> <to uri="activemq:BigSpendersQueue"/> </filter> </route> Writing the expression beanThe bean in the above examples is just any old Java Bean with a method called isGoldCustomer() that returns some object that is easily converted to a boolean value in this case, as its used as a predicate. So we could implement it like this... public class MyBean { public boolean isGoldCustomer(Exchange exchange) { ... } } We can also use the Bean Integration annotations. For example you could do... public boolean isGoldCustomer(String body) {...} or public boolean isGoldCustomer(@Header(name = "foo") Integer fooHeader) {...} So you can bind parameters of the method to the Exchange, the Message or individual headers, properties, the body or other expressions. Non registry beansAs of Camel 1.5 the Bean Language also supports invoking beans that isn't registered in the Registry. This is usable for quickly to invoke a bean from Java DSL where you don't need to register the bean in the Registry such as the Spring ApplicationContext. Camel can instantiate the bean and invoke the method if given a class or invoke an already existing instance. This is illustrated from the example below:
from("activemq:topic:OrdersTopic").
filter().expression(BeanLanguage(MyBean.class, "isGoldCustomer")).
to("activemq:BigSpendersQueue");
The 2nd parameter isGoldCustomer is an optional parameter to explicit set the method name to invoke. If not provided Camel will try to invoke the best suited method. If case of ambiguity Camel will thrown an Exception. In these situations the 2nd parameter can solve this problem. Also the code is more readable if the method name is provided. The 1st parameter can also be an existing instance of a Bean such as: private MyBean my; from("activemq:topic:OrdersTopic"). filter().expression(BeanLanguage.bean(my, "isGoldCustomer")). to("activemq:BigSpendersQueue"); In Camel 2.2 onwards you can avoid the BeanLanguage and have it just as: private MyBean my; from("activemq:topic:OrdersTopic"). filter().expression(bean(my, "isGoldCustomer")). to("activemq:BigSpendersQueue"); Which also can be done in a bit shorter and nice way: private MyBean my; from("activemq:topic:OrdersTopic"). filter().method(my, "isGoldCustomer"). to("activemq:BigSpendersQueue"); Other examplesWe have some test cases you can look at if it'll help
DependenciesThe Bean language is part of camel-core. Constant Expression LanguageThe Constant Expression Language is really just a way to specify constant strings as a type of expression. Available as of Camel 1.5 Example usageThe setHeader element of the Spring DSL can utilize a constant expression like: <route> <from uri="seda:a"/> <setHeader headerName="theHeader"> <constant>the value</constant> </setHeader> <to uri="mock:b"/> </route> in this case, the Message coming from the seda:a Endpoint will have 'theHeader' header set to the constant value 'the value'. And the same example using Java DSL: from("seda:a").setHeader("theHeader", constant("the value")).to("mock:b"); DependenciesThe Constant language is part of camel-core. ELCamel supports the unified JSP and JSF Expression Language via the JUEL to allow an Expression or Predicate to be used in the DSL or Xml Configuration. For example you could use EL inside a Message Filter in XML <route> <from uri="seda:foo"/> <filter> <el>${in.headers.foo == 'bar'}</el> <to uri="seda:bar"/> </filter> </route> You could also use slightly different syntax, e.g. if the header name is not a valid identifier: <route> <from uri="seda:foo"/> <filter> <el>${in.headers['My Header'] == 'bar'}</el> <to uri="seda:bar"/> </filter> </route> You could use EL to create an Predicate in a Message Filter or as an Expression for a Recipient List Variables
SamplesYou can use EL dot notation to invoke operations. If you for instance have a body that contains a POJO that has a getFamiliyName method then you can construct the syntax as follows:
"$in.body.familyName"
DependenciesTo use EL in your camel routes you need to add the a dependency on camel-juel which implements the EL language. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-juel</artifactId> <version>1.6.1</version> </dependency> Otherwise you'll also need to include JUEL. Header Expression LanguageThe Header Expression Language allows you to extract values of named headers. Available as of Camel 1.5 Example usageThe recipientList element of the Spring DSL can utilize a header expression like: <route> <from uri="direct:a" /> <!-- use comma as a delimiter for String based values --> <recipientList delimiter=","> <header>myHeader</header> </recipientList> </route> In this case, the list of recipients are contained in the header 'myHeader'. And the same example in Java DSL: from("direct:a").recipientList(header("myHeader")); And with a slightly different syntax where you use the builder to the fullest (i.e. avoid using parameters but using stacked operations, notice that header is not a parameter but a stacked method call) from("direct:a").recipientList().header("myHeader"); DependenciesThe Header language is part of camel-core. JXPathCamel supports JXPath to allow XPath expressions to be used on beans in an Expression or Predicate to be used in the DSL or Xml Configuration. For example you could use JXPath to create an Predicate in a Message Filter or as an Expression for a Recipient List. From 1.3 of Camel onwards you can use XPath expressions directly using smart completion in your IDE as follows from("queue:foo").filter(). jxpath("/in/body/foo"). to("queue:bar") Variables
Using XML configurationIf you prefer to configure your routes in your Spring XML file then you can use JXPath expressions as follows <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="activemq:MyQueue"/> <filter> <jxpath>in/body/name = 'James'</xpath> <to uri="mqseries:SomeOtherQueue"/> </filter> </route> </camelContext> </beans> ExamplesHere is a simple example using a JXPath expression as a predicate in a Message Filter from("direct:start"). filter().jxpath("in/body/name='James'"). to("mock:result"); JXPath injectionYou can use Bean Integration to invoke a method on a bean and use various languages such as JXPath to extract a value from the message and bind it to a method parameter. For example public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@JXPath("in/body/foo") String correlationID, @Body String body) { // process the inbound message here } } DependenciesTo use JXpath in your camel routes you need to add the a dependency on camel-jxpath which implements the JXpath language. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jxpath</artifactId> <version>1.4.0</version> </dependency> Otherwise, you'll also need Commons JXPath. MvelAvialable in Camel 2.0 Camel allows Mvel to be used as an Expression or Predicate the DSL or Xml Configuration. You could use Mvel to create an Predicate in a Message Filter or as an Expression for a Recipient List You can use Mvel dot notation to invoke operations. If you for instance have a body that contains a POJO that has a getFamiliyName method then you can construct the syntax as follows: "request.body.familyName" // or "getRequest().getBody().getFamilyName()" Variables
SamplesFor example you could use Mvel inside a Message Filter in XML <route> <from uri="seda:foo"/> <filter> <mvel>request.headers.foo == 'bar'</mvel> <to uri="seda:bar"/> </filter> </route> And the sample using Java DSL: from("seda:foo").filter().mvel("request.headers.foo == 'bar'").to("seda:bar"); DependenciesTo use Mvel in your camel routes you need to add the a dependency on camel-mvel which implements the Mvel language. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-mvel</artifactId> <version>2.0.0</version> </dependency> Otherwise, you'll also need MVEL OGNLCamel allows OGNL to be used as an Expression or Predicate the DSL or Xml Configuration. You could use OGNL to create an Predicate in a Message Filter or as an Expression for a Recipient List You can use OGNL dot notation to invoke operations. If you for instance have a body that contains a POJO that has a getFamiliyName method then you can construct the syntax as follows: "request.body.familyName" // or "getRequest().getBody().getFamilyName()" Variables
SamplesFor example you could use OGNL inside a Message Filter in XML <route> <from uri="seda:foo"/> <filter> <ognl>request.headers.foo == 'bar'</ognl> <to uri="seda:bar"/> </filter> </route> And the sample using Java DSL: from("seda:foo").filter().ognl("request.headers.foo == 'bar'").to("seda:bar"); DependenciesTo use OGNL in your camel routes you need to add the a dependency on camel-ognl which implements the OGNL language. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ognl</artifactId> <version>1.4.0</version> </dependency> Otherwise, you'll also need OGNL Property Expression LanguageThe Property Expression Language allows you to extract values of named exchange properties. Available as of Camel 2.0 Example usageThe recipientList element of the Spring DSL can utilize a property expression like: <route> <from uri="direct:a" /> <recipientList> <property>myProperty</property> </recipientList> </route> In this case, the list of recipients are contained in the property 'myProperty'. And the same example in Java DSL: from("direct:a").recipientList(property("myProperty")); And with a slightly different syntax where you use the builder to the fullest (i.e. avoid using parameters but using stacked operations, notice that property is not a parameter but a stacked method call) from("direct:a").recipientList().property("myProperty"); DependenciesThe Property language is part of camel-core. Scripting LanguagesCamel supports a number of scripting languages which can be used to create an Expression or Predicate via the standard JSR 223 which is a standard part of Java 6. The following scripting languages are integrated into the DSL:
However any JSR 223 scripting language can be used using the generic DSL methods. ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> See AlsoBeanShellCamel supports BeanShell among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration. To use a BeanShell expression use the following Java code:
...choice()
.when(script("beanshell", "request.getHeaders().get(\"foo\").equals(\"bar\")"))
.to("...")
Or the something like this in your Spring XML: <filter> <language language="beanshell">request.getHeaders().get("Foo") == null</language> ...
You could follow the examples above to create an Predicate in a Message Filter or as an Expression for a Recipient List ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> JavaScriptCamel supports JavaScript/ECMAScript among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration. To use a JavaScript expression use the following Java code
... javaScript("someJavaScriptExpression") ...
For example you could use the javaScript function to create an Predicate in a Message Filter or as an Expression for a Recipient List ExampleIn the sample below we use JavaScript to create a Predicate use in the route path, to route exchanges from admin users to a special queue.
from("direct:start")
.choice()
.when().javaScript("request.headers.get('user') == 'admin'").to("seda:adminQueue")
.otherwise()
.to("seda:regularQueue");
And a Spring DSL sample as well:
<route>
<from uri="direct:start"/>
<choice>
<when>
<javaScript>request.headers.get('user') == 'admin'</javaScript>
<to uri="seda:adminQueue"/>
</when>
<otherwise>
<to uri="seda:regularQueue"/>
</otherwise>
</choice>
</route>
ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> GroovyCamel supports Groovy among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration. To use a Groovy expression use the following Java code
... groovy("someGroovyExpression") ...
For example you could use the groovy function to create an Predicate in a Message Filter or as an Expression for a Recipient List Example// lets route if a line item is over $100 from("queue:foo").filter(groovy("request.lineItems.any { i -> i.value > 100 }")).to("queue:bar") And the Spring DSL:
<route>
<from uri="queue:foo"/>
<filter>
<groovy>request.lineItems.any { i -> i.value > 100 }</groovy>
<to uri="queue:bar"/>
</filter>
</route>
ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> PythonCamel supports Python among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration. To use a Python expression use the following Java code
... python("somePythonExpression") ...
For example you could use the python function to create an Predicate in a Message Filter or as an Expression for a Recipient List ExampleIn the sample below we use Python to create a Predicate use in the route path, to route exchanges from admin users to a special queue.
from("direct:start")
.choice()
.when().python("request.headers['user'] == 'admin'").to("seda:adminQueue")
.otherwise()
.to("seda:regularQueue");
And a Spring DSL sample as well:
<route>
<from uri="direct:start"/>
<choice>
<when>
<python>request.headers['user'] == 'admin'</python>
<to uri="seda:adminQueue"/>
</when>
<otherwise>
<to uri="seda:regularQueue"/>
</otherwise>
</choice>
</route>
ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> PHPCamel supports PHP among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration. To use a PHP expression use the following Java code
... php("somePHPExpression") ...
For example you could use the php function to create an Predicate in a Message Filter or as an Expression for a Recipient List ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> RubyCamel supports Ruby among other Scripting Languages to allow an Expression or Predicate to be used in the DSL or Xml Configuration. To use a Ruby expression use the following Java code
... ruby("someRubyExpression") ...
For example you could use the ruby function to create an Predicate in a Message Filter or as an Expression for a Recipient List ExampleIn the sample below we use Ruby to create a Predicate use in the route path, to route exchanges from admin users to a special queue.
from("direct:start")
.choice()
.when().ruby("$request.headers['user'] == 'admin'").to("seda:adminQueue")
.otherwise()
.to("seda:regularQueue");
And a Spring DSL sample as well:
<route>
<from uri="direct:start"/>
<choice>
<when>
<ruby>$request.headers['user'] == 'admin'</ruby>
<to uri="seda:adminQueue"/>
</when>
<otherwise>
<to uri="seda:regularQueue"/>
</otherwise>
</choice>
</route>
ScriptContextThe JSR-223 scripting languages ScriptContext is pre configured with the following attributes all set at ENGINE_SCOPE:
AttributesYou can add your own attributes with the attribute(name, value) DSL method, such as: In the sample below we add an attribute user that is an object we already have instantiated as myUser. This object has a getFirstName() method that we want to set as header on the message. We use the groovy language to concat the first and last name into a single string that is returned. from("direct:in").setHeader("name").groovy("'$user.firstName $user.lastName'").attribute("user", myUser).to("seda:users"); Any scripting languageCamel can run any JSR-223 scripting languages using the script DSL method such as: from("direct:in").setHeader("firstName").script("jaskel", "user.firstName").attribute("user", myUser).to("seda:users"); This is a bit different using the Spring DSL where you use the expression element that doesn't support setting attributes (yet):
<from uri="direct:in"/>
<setHeader headerName="firstName">
<expression language="jaskel">user.firstName</expression>
</setHeader>
<to uri="seda:users"/>
You can also use predicates e.g. in a Filter:
<filter>
<language language="beanshell">request.getHeaders().get("Foo").equals("Bar")</language>
<to uri="direct:next" />
</filter>
See Scripting Languages for the list of languages with explicit DSL support. Some languages without specific DSL support but known to work with these generic methods include:
Additional arguments to ScriptingEngineAvailable as of Camel 2.8 You can provide additional arguments to the ScriptingEngine using a header on the Camel message with the key CamelScriptArguments. public void testArgumentsExample() throws Exception { if (!ScriptTestHelper.canRunTestOnThisPlatform()) { return; } getMockEndpoint("mock:result").expectedMessageCount(0); getMockEndpoint("mock:unmatched").expectedMessageCount(1); // additional arguments to ScriptEngine Map<String, Object> arguments = new HashMap<String, Object>(); arguments.put("foo", "bar"); arguments.put("baz", 7); // those additional arguments is provided as a header on the Camel Message template.sendBodyAndHeader("direct:start", "hello", ScriptBuilder.ARGUMENTS, arguments); assertMockEndpointsSatisfied(); } Using properties functionAvailable as of Camel 2.9 If you need to use the Properties component from a script to lookup property placeholders, then its a bit cumbersome to do so. .setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')") From Camel 2.9 onwards you can now use the properties function and the same example is simpler: .setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))") DependenciesTo use scripting languages in your camel routes you need to add the a dependency on camel-script which integrates the JSR-223 scripting engine. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-script</artifactId> <version>x.x.x</version> </dependency> Simple Expression LanguageThe Simple Expression Language was a really simple language you can use, but has since grown more powerful. Its primarily intended for being a really small and simple language for evaluating Expression and Predicate without requiring any new dependencies or knowledge of XPath; so its ideal for testing in camel-core. Its ideal to cover 95% of the common use cases when you need a little bit of expression based script in your Camel routes. However for much more complex use cases you are generally recommended to choose a more expressive and powerful language such as:
The simple language uses ${body} placeholders for complex expressions where the expression contains constant literals. The ${ } placeholders can be omitted if the expression is only the token itself.
To get the body of the in message: "body", or "in.body" or "${body}". A complex expression must use ${ } placeholders, such as: "Hello ${in.header.name} how are you?". You can have multiple functions in the same expression: "Hello ${in.header.name} this is ${in.header.me} speaking". Variables
OGNL expression supportAvailable as of Camel 2.3 The Simple and Bean language now supports a Camel OGNL notation for invoking beans in a chain like fashion. Then you can use Camel OGNL notation to access the address object: simple("${body.address}") simple("${body.address.street}") simple("${body.address.zip}") Camel understands the shorthand names for getters, but you can invoke any method or use the real name such as: simple("${body.address}") simple("${body.getAddress.getStreet}") simple("${body.address.getZip}") simple("${body.doSomething}") You can also use the null safe operator (?.) to avoid NPE if for example the body does NOT have an address
simple("${body?.address?.street}")
Its also possible to index in Map or List types, so you can do:
simple("${body[foo].name}")
To assume the body is Map based and lookup the value with foo as key, and invoke the getName method on that value. You can access the Map or List objects directly using their key name (with or without dots) : simple("${body[foo]}") simple("${body[this.is.foo]}") Suppose there was no value with the key foo then you can use the null safe operator to avoid the NPE as shown:
simple("${body[foo]?.name}")
You can also access List types, for example to get lines from the address you can do: simple("${body.address.lines[0]}") simple("${body.address.lines[1]}") simple("${body.address.lines[2]}") There is a special last keyword which can be used to get the last value from a list.
simple("${body.address.lines[last]}")
And to get the 2nd last you can subtract a number, so we can use last-1 to indicate this:
simple("${body.address.lines[last-1]}")
And the 3rd last is of course:
simple("${body.address.lines[last-2]}")
And yes you can combine this with the operator support as shown below:
simple("${body.address.zip} > 1000")
Operator supportAvailable as of Camel 2.0 To enable it the left value must be enclosed in ${ }. The syntax is:
${leftValue} OP rightValue
Where the rightValue can be a String literal enclosed in ' ', null, a constant value or another expression enclosed in ${ }.
Camel will automatically type convert the rightValue type to the leftValue type, so its able to eg. convert a string into a numeric so you can use > comparison for numeric values. The following operators are supported:
And the following unary operators can be used:
And the following logical operators can be used to group expressions:
The syntax for AND is:
${leftValue} OP rightValue and ${leftValue} OP rightValue
And the syntax for OR is:
${leftValue} OP rightValue or ${leftValue} OP rightValue
Some examples: simple("${in.header.foo} == 'foo'") // here Camel will type convert '100' into the type of in.header.bar and if its an Integer '100' will also be converter to an Integer simple("${in.header.bar} == '100'") simple("${in.header.bar} == 100") // 100 will be converter to the type of in.header.bar so we can do > comparison simple("${in.header.bar} > 100")
// testing for null simple("${in.header.baz} == null") // testing for not null simple("${in.header.baz} != null") And a bit more advanced example where the right value is another expression simple("${in.header.date} == ${date:now:yyyyMMdd}") simple("${in.header.type} == ${bean:orderService?method=getOrderType}") And an example with contains, testing if the title contains the word Camel
simple("${in.header.title} contains 'Camel'")
And an example with regex, testing if the number header is a 4 digit value:
simple("${in.header.number} regex '\\d{4}'")
And finally an example if the header equals any of the values in the list. Each element must be separated by comma, and no space around.
simple("${in.header.type} in 'gold,silver'")
And for all the last 3 we also support the negate test using not:
simple("${in.header.type} not in 'gold,silver'")
And you can test if the type is a certain instance, eg for instance a String
simple("${in.header.type} is 'java.lang.String'")
We have added a shorthand for all java.lang types so you can write it as:
simple("${in.header.type} is 'String'")
Ranges are also supported. The range interval requires numbers and both from and end are inclusive. For instance to test whether a value is between 100 and 199:
simple("${in.header.number} range 100..199")
Notice we use .. in the range without spaces. Its based on the same syntax as Groovy. From Camel 2.9 onwards the range value must be in single quotes
simple("${in.header.number} range '100..199'")
Using and / orIf you have two expressions you can combine them with the and or or operator.
For instance:
simple("${in.header.title} contains 'Camel' and ${in.header.type'} == 'gold'")
And of course the or is also supported. The sample would be:
simple("${in.header.title} contains 'Camel' or ${in.header.type'} == 'gold'")
Notice: Currently and or or can only be used once in a simple language expression. This might change in the future.
simple("${in.header.title} contains 'Camel' and ${in.header.type'} == 'gold' and ${in.header.number} range 100..200")
SamplesIn the Spring XML sample below we filter based on a header value:
<from uri="seda:orders">
<filter>
<simple>in.header.foo</simple>
<to uri="mock:fooOrders"/>
</filter>
</from>
The Simple language can be used for the predicate test above in the Message Filter pattern, where we test if the in message has a foo header (a header with the key foo exists). If the expression evaluates to true then the message is routed to the mock:foo endpoint, otherwise its lost in the deep blue sea The same example in Java DSL:
from("seda:orders")
.filter().simple("${in.header.foo}").to("seda:fooOrders");
You can also use the simple language for simple text concatenations such as: from("direct:hello").transform().simple("Hello ${in.header.user} how are you?").to("mock:reply"); Notice that we must use ${ } placeholders in the expression now to allow Camel to parse it correctly. And this sample uses the date command to output current date. from("direct:hello").transform().simple("The today is ${date:now:yyyyMMdd} and its a great day.").to("mock:reply"); And in the sample below we invoke the bean language to invoke a method on a bean to be included in the returned string: from("direct:order").transform().simple("OrderId: ${bean:orderIdGenerator}").to("mock:reply"); Where orderIdGenerator is the id of the bean registered in the Registry. If using Spring then its the Spring bean id. If we want to declare which method to invoke on the order id generator bean we must prepend .method name such as below where we invoke the generateId method. from("direct:order").transform().simple("OrderId: ${bean:orderIdGenerator.generateId}").to("mock:reply"); And in Camel 2.0 we can use the ?method=methodname option that we are familiar with the Bean component itself: from("direct:order").transform().simple("OrderId: ${bean:orderIdGenerator?method=generateId}").to("mock:reply"); And from Camel 2.3 onwards you can also convert the body to a given type, for example to ensure its a String you can do: <transform> <simple>Hello ${bodyAs(String)} how are you?</simple> </transform> There are a few types which have a shorthand notation, so we can use String instead of java.lang.String. These are: byte[], String, Integer, Long. All other types must use their FQN name, e.g. org.w3c.dom.Document. Its also possible to lookup a value from a header Map in Camel 2.3 onwards: <transform> <simple>The gold value is ${header.type[gold]}</simple> </transform> In the code above we lookup the header with name type and regard it as a java.util.Map and we then lookup with the key gold and return the value. From Camel 2.9 onwards you can nest functions, such as shown below: <setHeader headerName="myHeader"> <simple>${properties:${header.someKey}}</simple> </setHeader> Setting result typeAvailable as of Camel 2.8 You can now provide a result type to the Simple expression, which means the result of the evaluation will be converted to the desired type. This is most useable to define types such as booleans, integers, etc. For example to set a header as a boolean type you can do: .setHeader("cool", simple("true", Boolean.class)) And in XML DSL
<setHeader headerName="cool">
<!-- use resultType to indicate that the type should be a java.lang.Boolean -->
<simple resultType="java.lang.Boolean">true</simple>
</setHeader>
Changing function start and end tokensAvailable as of Camel 2.9 You can configure the function start and end tokens - ${ } using the methods changeFunctionStartToken and changeFunctionEndToken on SimpleLanguage, using Java code. From Spring XML you can define a <bean> tag with the new changed tokens in the constructor as shown below:
<!-- configure Simple to use custom prefix/suffix tokens -->
<bean id="simple" class="org.apache.camel.language.simple.SimpleLanguage">
<constructor-arg name="functionStartToken" value="["/>
<constructor-arg name="functionEndToken" value="]"/>
</bean>
In the example above we use [ ] as the changed tokens. Notice by changing the start/end tokens you change those in all the Camel applications which share the same camel-core on their classpath. DependenciesThe Simple language is part of camel-core. File Expression LanguageAvailable as of Camel 1.5
The File Expression Language is an extension to the Simple language, adding file related capabilities. These capabilities are related to common use cases working with file path and names. The goal is to allow expressions to be used with the File and FTP components for setting dynamic file patterns for both consumer and producer. SyntaxThis language is an extension to the Simple language so the Simple syntax applies also. So the table below only lists the additional. All the file tokens use the same expression name as the method on the java.io.File object, for instance file:absolute refers to the java.io.File.getAbsolute() method. Notice that not all expressions are supported by the current Exchange. For instance the FTP component supports some of the options, where as the File component supports all of them.
File token exampleRelative pathsWe have a java.io.File handle for the file hello.txt in the following relative directory: .\filelanguage\test. And we configure our endpoint to use this starting directory .\filelanguage. The file tokens will return as:
Absolute pathsWe have a java.io.File handle for the file hello.txt in the following absolute directory: \workspace\camel\camel-core\target\filelanguage\test. And we configure out endpoint to use the absolute starting directory \workspace\camel\camel-core\target\filelanguage. The file tokens will return as:
SamplesYou can enter a fixed Constant expression such as myfile.txt:
fileName="myfile.txt"
Lets assume we use the file consumer to read files and want to move the read files to backup folder with the current date as a sub folder. This can be archieved using an expression like:
fileName="backup/${date:now:yyyyMMdd}/${file:name.noext}.bak"
relative folder names are also supported so suppose the backup folder should be a sibling folder then you can append .. as:
fileName="../backup/${date:now:yyyyMMdd}/${file:name.noext}.bak"
As this is an extension to the Simple language we have access to all the goodies from this language also, so in this use case we want to use the in.header.type as a parameter in the dynamic expression:
fileName="../backup/${date:now:yyyyMMdd}/type-${in.header.type}/backup-of-${file:name.noext}.bak"
If you have a custom Date you want to use in the expression then Camel supports retrieving dates from the message header.
fileName="orders/order-${in.header.customerId}-${date:in.header.orderDate:yyyyMMdd}.xml"
And finally we can also use a bean expression to invoke a POJO class that generates some String output (or convertible to String) to be used:
fileName="uniquefile-${bean:myguidgenerator.generateid}.txt"
And of course all this can be combined in one expression where you can use the File Language, Simple and the Bean language in one combined expression. This is pretty powerful for those common file path patterns. Using Spring PropertyPlaceholderConfigurer together with the File componentIn Camel you can use the File Language directly from the Simple language which makes a Content Based Router easier to do in Spring XML, where we can route based on file extensions as shown below: <from uri="file://input/orders"/> <choice> <when> <simple>${file:ext} == 'txt'</simple> <to uri="bean:orderService?method=handleTextFiles"/> </when> <when> <simple>${file:ext} == 'xml'</simple> <to uri="bean:orderService?method=handleXmlFiles"/> </when> <otherwise> <to uri="bean:orderService?method=handleOtherFiles"/> </otherwise> </choice> If you use the fileName option on the File endpoint to set a dynamic filename using the File Language then make sure you bundle-context.xml <bean id="propertyPlaceholder" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:bundle-context.cfg" /> </bean> <bean id="sampleRoute" class="SampleRoute"> <property name="fromEndpoint" value="${fromEndpoint}" /> <property name="toEndpoint" value="${toEndpoint}" /> </bean> bundle-context.cfg
fromEndpoint=activemq:queue:test
toEndpoint=file://fileRoute/out?fileName=test-$simple{date:now:yyyyMMdd}.txt
Notice how we use the $simple{ } syntax in the toEndpoint above. org.springframework.beans.factory.BeanDefinitionStoreException: Invalid bean definition with name 'sampleRoute' defined in class path resource [bundle-context.xml]: Could not resolve placeholder 'date:now:yyyyMMdd' DependenciesThe File language is part of camel-core. SQLThe SQL support is added by JoSQL and is primarily used for performing SQL queries on in-memory objects. If you prefer to perform actual database queries then check out the JPA component. To use SQL in your camel routes you need to add the a dependency on camel-josql which implements the SQL language. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-josql</artifactId> <version>2.5.0</version> </dependency> Camel supports SQL to allow an Expression or Predicate to be used in the DSL or Xml Configuration. For example you could use SQL to create an Predicate in a Message Filter or as an Expression for a Recipient List. from("queue:foo").setBody().sql("select * from MyType").to("queue:bar") And the spring DSL: <from uri="queue:foo"/> <setBody> <sql>select * from MyType</sql> </setBody> <to uri="queue:bar"/> Variables
XPathCamel supports XPath to allow an Expression or Predicate to be used in the DSL or Xml Configuration. For example you could use XPath to create an Predicate in a Message Filter or as an Expression for a Recipient List. from("queue:foo"). filter().xpath("//foo")). to("queue:bar") from("queue:foo"). choice().xpath("//foo")).to("queue:bar"). otherwise().to("queue:others"); NamespacesIn 1.3 onwards you can easily use namespaces with XPath expressions using the Namespaces helper class. Namespaces ns = new Namespaces("c", "http://acme.com/cheese"); from("direct:start").filter(). xpath("/c:person[@name='James']", ns). to("mock:result"); VariablesVariables in XPath is defined in different namespaces. The default namespace is http://camel.apache.org/schema/spring.
Camel will resolve variables according to either:
Namespace givenIf the namespace is given then Camel is instructed exactly what to return. However when resolving either in or out Camel will try to resolve a header with the given local part first, and return it. If the local part has the value body then the body is returned instead. No namespace givenIf there is no namespace given then Camel resolves only based on the local part. Camel will try to resolve a variable in the following steps:
FunctionsCamel adds the following XPath functions that can be used to access the exchange:
Notice: function:properties and function:simple is not supported when the return type is a NodeSet, such as when using with a Splitter EIP. Here's an example showing some of these functions in use. from("direct:start").choice() .when().xpath("in:header('foo') = 'bar'").to("mock:x") .when().xpath("in:body() = '<two/>'").to("mock:y") .otherwise().to("mock:z"); And the new functions introduced in Camel 2.5: // setup properties component PropertiesComponent properties = new PropertiesComponent(); properties.setLocation("classpath:org/apache/camel/builder/xml/myprop.properties"); context.addComponent("properties", properties); // myprop.properties contains the following properties // foo=Camel // bar=Kong from("direct:in").choice() // $type is a variable for the header with key type // here we use the properties function to lookup foo from the properties files // which at runtime will be evaluted to 'Camel' .when().xpath("$type = function:properties('foo')") .to("mock:camel") // here we use the simple language to evaluate the expression // which at runtime will be evaluated to 'Donkey Kong' .when().xpath("//name = function:simple('Donkey ${properties:bar}')") .to("mock:donkey") .otherwise() .to("mock:other") .end(); Using XML configurationIf you prefer to configure your routes in your Spring XML file then you can use XPath expressions as follows <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring" xmlns:foo="http://example.com/person"> <route> <from uri="activemq:MyQueue"/> <filter> <xpath>/foo:person[@name='James']</xpath> <to uri="mqseries:SomeOtherQueue"/> </filter> </route> </camelContext> </beans> Notice how we can reuse the namespace prefixes, foo in this case, in the XPath expression for easier namespace based XPath expressions! See also this discussion on the mailinglist about using your own namespaces with xpath Setting result typeThe XPath expression will return a result type using native XML objects such as org.w3c.dom.NodeList. But many times you want a result type to be a String. To do this you have to instruct the XPath which result type to use. In Java DSL: xpath("/foo:person/@id", String.class) In Spring DSL you use the resultType attribute to provide a fully qualified classname: <xpath resultType="java.lang.String">/foo:person/@id</xpath> In @XPath:
@XPath(value = "concat('foo-',//order/name/)", resultType = String.class) String name)
Where we use the xpath function concat to prefix the order name with foo-. In this case we have to specify that we want a String as result type so the concat function works. ExamplesHere is a simple example using an XPath expression as a predicate in a Message Filter from("direct:start"). filter().xpath("/person[@name='James']"). to("mock:result"); If you have a standard set of namespaces you wish to work with and wish to share them across many different XPath expressions you can use the NamespaceBuilder as shown in this example // lets define the namespaces we'll need in our filters Namespaces ns = new Namespaces("c", "http://acme.com/cheese") .add("xsd", "http://www.w3.org/2001/XMLSchema"); // now lets create an xpath based Message Filter from("direct:start"). filter(ns.xpath("/c:person[@name='James']")). to("mock:result"); In this sample we have a choice construct. The first choice evaulates if the message has a header key type that has the value Camel. from("direct:in").choice() // using $headerName is special notation in Camel to get the header key .when().xpath("$type = 'Camel'") .to("mock:camel") // here we test for the body name tag .when().xpath("//name = 'Kong'") .to("mock:donkey") .otherwise() .to("mock:other") .end(); And the spring XML equivalent of the route: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:in"/> <choice> <when> <xpath>$type = 'Camel'</xpath> <to uri="mock:camel"/> </when> <when> <xpath>//name = 'Kong'</xpath> <to uri="mock:donkey"/> </when> <otherwise> <to uri="mock:other"/> </otherwise> </choice> </route> </camelContext> XPath injectionYou can use Bean Integration to invoke a method on a bean and use various languages such as XPath to extract a value from the message and bind it to a method parameter. The default XPath annotation has SOAP and XML namespaces available. If you want to use your own namespace URIs in an XPath expression you can use your own copy of the XPath annotation to create whatever namespace prefixes you want to use. import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.w3c.dom.NodeList; import org.apache.camel.component.bean.XPathAnnotationExpressionFactory; import org.apache.camel.language.LanguageAnnotation; import org.apache.camel.language.NamespacePrefix; @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER}) @LanguageAnnotation(language = "xpath", factory = XPathAnnotationExpressionFactory.class) public @interface MyXPath { String value(); // You can add the namespaces as the default value of the annotation NamespacePrefix[] namespaces() default { @NamespacePrefix(prefix = "n1", uri = "http://example.org/ns1"), @NamespacePrefix(prefix = "n2", uri = "http://example.org/ns2")}; Class<?> resultType() default NodeList.class; } i.e. cut and paste upper code to your own project in a different package and/or annotation name then add whatever namespace prefix/uris you want in scope when you use your annotation on a method parameter. Then when you use your annotation on a method parameter all the namespaces you want will be available for use in your XPath expression. NOTE this feature is supported from Camel 1.6.1. For example public class Foo { @MessageDriven(uri = "activemq:my.queue") public void doSomething(@MyXPath("/ns1:foo/ns2:bar/text()") String correlationID, @Body String body) { // process the inbound message here } } Using XPathBuilder without an ExchangeAvailable as of Camel 2.3 You can now use the org.apache.camel.builder.XPathBuilder without the need for an Exchange. This comes handy if you want to use it as a helper to do custom xpath evaluations. It requires that you pass in a CamelContext since a lot of the moving parts inside the XPathBuilder requires access to the Camel Type Converter and hence why CamelContext is needed. For example you can do something like this: boolean matches = XPathBuilder.xpath("/foo/bar/@xyz").matches(context, "<foo><bar xyz='cheese'/></foo>")); This will match the given predicate. You can also evaluate for example as shown in the following three examples:
String name = XPathBuilder.xpath("foo/bar").evaluate(context, "<foo><bar>cheese</bar></foo>", String.class);
Integer number = XPathBuilder.xpath("foo/bar").evaluate(context, "<foo><bar>123</bar></foo>", Integer.class);
Boolean bool = XPathBuilder.xpath("foo/bar").evaluate(context, "<foo><bar>true</bar></foo>", Boolean.class);
Evaluating with a String result is a common requirement and thus you can do it a bit simpler:
String name = XPathBuilder.xpath("foo/bar").evaluate(context, "<foo><bar>cheese</bar></foo>");
Using Saxon with XPathBuilderAvailable as of Camel 2.3 You need to add camel-saxon as dependency to your project. Its now easier to use Saxon with the XPathBuilder which can be done in several ways as shown below. Using a factory // create a Saxon factory XPathFactory fac = new net.sf.saxon.xpath.XPathFactoryImpl(); // create a builder to evaluate the xpath using the saxon factory XPathBuilder builder = XPathBuilder.xpath("tokenize(/foo/bar, '_')[2]").factory(fac); // evaluate as a String result String result = builder.evaluate(context, "<foo><bar>abc_def_ghi</bar></foo>"); assertEquals("def", result); Using ObjectModel // create a builder to evaluate the xpath using saxon based on its object model uri XPathBuilder builder = XPathBuilder.xpath("tokenize(/foo/bar, '_')[2]").objectModel("http://saxon.sf.net/jaxp/xpath/om"); // evaluate as a String result String result = builder.evaluate(context, "<foo><bar>abc_def_ghi</bar></foo>"); assertEquals("def", result); The easy one // create a builder to evaluate the xpath using saxon XPathBuilder builder = XPathBuilder.xpath("tokenize(/foo/bar, '_')[2]").saxon(); // evaluate as a String result String result = builder.evaluate(context, "<foo><bar>abc_def_ghi</bar></foo>"); assertEquals("def", result); Setting a custom XPathFactory using System PropertyAvailable as of Camel 2.3 Camel now supports reading the JVM system property javax.xml.xpath.XPathFactory that can be used to set a custom XPathFactory to use. This unit test shows how this can be done to use Saxon instead: // set system property with the XPath factory to use which is Saxon System.setProperty(XPathFactory.DEFAULT_PROPERTY_NAME + ":" + "http://saxon.sf.net/jaxp/xpath/om", "net.sf.saxon.xpath.XPathFactoryImpl"); // create a builder to evaluate the xpath using saxon XPathBuilder builder = XPathBuilder.xpath("tokenize(/foo/bar, '_')[2]"); // evaluate as a String result String result = builder.evaluate(context, "<foo><bar>abc_def_ghi</bar></foo>"); assertEquals("def", result); Camel will log at INFO level if it uses a non default XPathFactory such as:
XPathBuilder INFO Using system property javax.xml.xpath.XPathFactory:http://saxon.sf.net/jaxp/xpath/om with value:
net.sf.saxon.xpath.XPathFactoryImpl when creating XPathFactory
To use Apache Xerces you can configure the system property -Djavax.xml.xpath.XPathFactory=org.apache.xpath.jaxp.XPathFactoryImpl Enabling Saxon from Spring DSLAvailable as of Camel 2.10 Similarly to Java DSL, to enable Saxon from Spring DSL you have three options: Specifying the factory <xpath factoryRef="saxonFactory" resultType="java.lang.String">current-dateTime()</xpath> Specifying the object model <xpath objectModel="http://saxon.sf.net/jaxp/xpath/om" resultType="java.lang.String">current-dateTime()</xpath> Shortcut <xpath saxon="true" resultType="java.lang.String">current-dateTime()</xpath> Namespace auditing to aid debuggingAvailable as of Camel 2.10 A large number of XPath-related issues that users frequently face are linked to the usage of namespaces. You may have some misalignment between the namespaces present in your message and those that your XPath expression is aware of or referencing. XPath predicates or expressions that are unable to locate the XML elements and attributes due to namespaces issues may simply look like "they are not working", when in reality all there is to it is a lack of namespace definition. Namespaces in XML are completely necessary, and while we would love to simplify their usage by implementing some magic or voodoo to wire namespaces automatically, truth is that any action down this path would disagree with the standards and would greatly hinder interoperability. Therefore, the utmost we can do is assist you in debugging such issues by adding two new features to the XPath Expression Language and are thus accesible from both predicates and expressions. Logging the Namespace Context of your XPath expression/predicateEvery time a new XPath expression is created in the internal pool, Camel will log the namespace context of the expression under the org.apache.camel.builder.xml.XPathBuilder logger. Since Camel represents Namespace Contexts in a hierarchical fashion (parent-child relationships), the entire tree is output in a recursive manner with the following format:
[me: {prefix -> namespace}, {prefix -> namespace}], [parent: [me: {prefix -> namespace}, {prefix -> namespace}], [parent: [me: {prefix -> namespace}]]]
Any of these options can be used to activate this logging:
Auditing namespacesCamel is able to discover and dump all namespaces present on every incoming message before evaluating an XPath expression, providing all the richness of information you need to help you analyse and pinpoint possible namespace issues. To achieve this, it in turn internally uses another specially tailored XPath expression to extract all namespace mappings that appear in the message, displaying the prefix and the full namespace URI(s) for each individual mapping. Some points to take into account:
You can enable this option in Java DSL and Spring DSL. Java DSL: XPathBuilder.xpath("/foo:person/@id", String.class).logNamespaces() Spring DSL: <xpath logNamespaces="true" resultType="String">/foo:person/@id</xpath> The result of the auditing will be appear at the INFO level under the org.apache.camel.builder.xml.XPathBuilder logger and will look like the following:
2012-01-16 13:23:45,878 [stSaxonWithFlag] INFO XPathBuilder - Namespaces discovered in message: {xmlns:a=[http://apache.org/camel], DEFAULT=[http://apache.org/default],
xmlns:b=[http://apache.org/camelA, http://apache.org/camelB]}
DependenciesThe XPath language is part of camel-core. XQueryCamel supports XQuery to allow an Expression or Predicate to be used in the DSL or Xml Configuration. For example you could use XQuery to create an Predicate in a Message Filter or as an Expression for a Recipient List. Options
Examplesfrom("queue:foo").filter(). xquery("//foo"). to("queue:bar") You can also use functions inside your query, in which case you need an explicit type conversion (or you will get a org.w3c.dom.DOMException: HIERARCHY_REQUEST_ERR) by passing the Class as a second argument to the xquery() method. from("direct:start"). recipientList().xquery("concat('mock:foo.', /person/@city)", String.class); VariablesThe IN message body will be set as the contextItem. Besides this these Variables is also added as parameters:
Using XML configurationIf you prefer to configure your routes in your Spring XML file then you can use XPath expressions as follows <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:foo="http://example.com/person" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="activemq:MyQueue"/> <filter> <xquery>/foo:person[@name='James']</xquery> <to uri="mqseries:SomeOtherQueue"/> </filter> </route> </camelContext> </beans> Notice how we can reuse the namespace prefixes, foo in this case, in the XPath expression for easier namespace based XQuery expressions! When you use functions in your XQuery expression you need an explicit type conversion which is done in the xml configuration via the @type attribute:
<xquery type="java.lang.String">concat('mock:foo.', /person/@city)</xquery>
Using XQuery as an endpointSometimes an XQuery expression can be quite large; it can essentally be used for Templating. So you may want to use an XQuery Endpoint so you can route using XQuery templates. The following example shows how to take a message of an ActiveMQ queue (MyQueue) and transform it using XQuery and send it to MQSeries. <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="activemq:MyQueue"/> <to uri="xquery:com/acme/someTransform.xquery"/> <to uri="mqseries:SomeOtherQueue"/> </route> </camelContext> ExamplesHere is a simple example using an XQuery expression as a predicate in a Message Filter from("direct:start").filter().xquery("/person[@name='James']").to("mock:result"); This example uses XQuery with namespaces as a predicate in a Message Filter Namespaces ns = new Namespaces("c", "http://acme.com/cheese"); from("direct:start"). filter().xquery("/c:person[@name='James']", ns). to("mock:result"); Learning XQueryXQuery is a very powerful language for querying, searching, sorting and returning XML. For help learning XQuery try these tutorials
You might also find the XQuery function reference useful DependenciesTo use XQuery in your camel routes you need to add the a dependency on camel-saxon which implements the XQuery language. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-saxon</artifactId> <version>1.4.0</version> </dependency> Data Format AppendixData FormatCamel supports a pluggable DataFormat to allow messages to be marshalled to and from binary or text formats to support a kind of Message Translator. The following data formats are currently supported:
And related is the following Type Converters: UnmarshallingIf you receive a message from one of the Camel Components such as File, HTTP or JMS you often want to unmarshal the payload into some bean so that you can process it using some Bean Integration or perform Predicate evaluation and so forth. To do this use the unmarshal word in the DSL in Java or the Xml Configuration. For example DataFormat jaxb = new JaxbDataFormat("com.acme.model"); from("activemq:My.Queue"). unmarshal(jaxb). to("mqseries:Another.Queue"); The above uses a named DataFormat of jaxb which is configured with a number of Java package names. You can if you prefer use a named reference to a data format which can then be defined in your Registry such as via your Spring XML file. You can also use the DSL itself to define the data format as you use it. For example the following uses Java serialization to unmarshal a binary file then send it as an ObjectMessage to ActiveMQ from("file://foo/bar"). unmarshal().serialization(). to("activemq:Some.Queue"); MarshallingMarshalling is the opposite of unmarshalling, where a bean is marshalled into some binary or textual format for transmission over some transport via a Camel Component. Marshalling is used in the same way as unmarshalling above; in the DSL you can use a DataFormat instance, you can configure the DataFormat dynamically using the DSL or you can refer to a named instance of the format in the Registry. The following example unmarshals via serialization then marshals using a named JAXB data format to perform a kind of Message Translator from("file://foo/bar"). unmarshal().serialization(). marshal("jaxb"). to("activemq:Some.Queue"); Using Spring XMLThis example shows how to configure the data type just once and reuse it on multiple routes <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <jaxb id="myJaxb" prettyPrint="true" contextPath="org.apache.camel.example"/> </dataFormats> <route> <from uri="direct:start"/> <marshal ref="myJaxb"/> <to uri="direct:marshalled"/> </route> <route> <from uri="direct:marshalled"/> <unmarshal ref="myJaxb"/> <to uri="mock:result"/> </route> </camelContext> You can also define reusable data formats as Spring beans <bean id="myJaxb" class="org.apache.camel.model.dataformat.JaxbDataFormat"> <property name="prettyPrint" value="true"/> <property name="contextPath" value="org.apache.camel.example"/> </bean> SerializationSerialization is a Data Format which uses the standard Java Serialization mechanism to unmarshal a binary payload into Java objects or to marshal Java objects into a binary blob. from("file://foo/bar"). unmarshal().serialization(). to("activemq:Some.Queue"); DependenciesThis data format is provided in camel-core so no additional dependencies is needed. JAXBJAXB is a Data Format which uses the JAXB2 XML marshalling standard which is included in Java 6 to unmarshal an XML payload into Java objects or to marshal Java objects into an XML payload. Using the Java DSLFor example the following uses a named DataFormat of jaxb which is configured with a number of Java package names to initialize the JAXBContext. DataFormat jaxb = new JaxbDataFormat("com.acme.model"); from("activemq:My.Queue"). unmarshal(jaxb). to("mqseries:Another.Queue"); You can if you prefer use a named reference to a data format which can then be defined in your Registry such as via your Spring XML file. e.g. from("activemq:My.Queue"). unmarshal("myJaxbDataType"). to("mqseries:Another.Queue"); Using Spring XMLThe following example shows how to use JAXB to unmarshal using Spring configuring the jaxb data type <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <unmarshal> <jaxb prettyPrint="true" contextPath="org.apache.camel.example"/> </unmarshal> <to uri="mock:result"/> </route> </camelContext> This example shows how to configure the data type just once and reuse it on multiple routes. For Camel versions below 1.5.0 you have to set the <jaxb> element directly in <camelContext>. <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <jaxb id="myJaxb" prettyPrint="true" contextPath="org.apache.camel.example"/> </dataFormats> <route> <from uri="direct:start"/> <marshal ref="myJaxb"/> <to uri="direct:marshalled"/> </route> <route> <from uri="direct:marshalled"/> <unmarshal ref="myJaxb"/> <to uri="mock:result"/> </route> </camelContext>
Partial marshalling/unmarshallingThis feature is new to Camel 2.2.0. <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:marshal"/> <marshal> <jaxb prettyPrint="false" contextPath="org.apache.camel.example" partClass="org.apache.camel.example.PurchaseOrder" fragment="true" partNamespace="{http://example.camel.org/apache}po" /> </marshal> <to uri="mock:marshal"/> </route> <route> <from uri="direct:unmarshal"/> <unmarshal> <jaxb prettyPrint="false" contextPath="org.apache.camel.example" partClass="org.apache.camel.example.Partial" /> </unmarshal> <to uri="mock:unmarshal"/> </route> </camelContext> For marshalling you have to add partNamespace attribute with QName of destination namespace. Example of Spring DSL you can find above. FragmentThis feature is new to Camel 2.8.0. Ignoring the NonXML CharacterThis feature is new to Camel 2.2.0.
This feature has been tested with Woodstox 3.2.9 and Sun JDK 1.6 StAX implementation. Working with the ObjectFactoryIf you use XJC to create the java class from the schema, you will get an ObjectFactory for you JAXB context. Since the ObjectFactory uses JAXBElement to hold the reference of the schema and element instance value, from Camel 1.5.1 jaxbDataformat will ignore the JAXBElement by default and you will get the element instance value instead of the JAXBElement object form the unmarshaled message body. Setting encodingIn Camel 1.6.1 and newer you can set the encoding option to use when marshalling. Its the Marshaller.JAXB_ENCODING encoding property on the JAXB Marshaller. In this Spring DSL we have defined to use iso-8859-1 as the encoding: <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <marshal> <jaxb prettyPrint="false" encoding="iso-8859-1" contextPath="org.apache.camel.example"/> </marshal> <to uri="mock:result"/> </route> </camelContext> DependenciesTo use JAXB in your camel routes you need to add the a dependency on camel-jaxb which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jaxb</artifactId> <version>1.6.0</version> </dependency> XmlBeansXmlBeans is a Data Format which uses the XmlBeans library to unmarshal an XML payload into Java objects or to marshal Java objects into an XML payload. from("activemq:My.Queue"). unmarshal().xmlBeans(). to("mqseries:Another.Queue"); DependenciesTo use XmlBeans in your camel routes you need to add the dependency on camel-xmlbeans which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-xmlbeans</artifactId> <version>2.8.0</version> </dependency> XStreamXStream is a Data Format which uses the XStream library to marshal and unmarshal Java objects to and from XML. // lets turn Object messages into XML then send to MQSeries from("activemq:My.Queue"). marshal().xstream(). to("mqseries:Another.Queue"); XMLInputFactory and XMLOutputFactoryThe XStream library uses the javax.xml.stream.XMLInputFactory and javax.xml.stream.XMLOutputFactory, you can control which implementation of this factory should be used. The Factory is discovered using this algorithm: How to set the XML encoding in Xstream DataFormat?From Camel 1.6.3 or Camel 2.2.0, you can set the encoding of XML in Xstream DataFormat by setting the Exchange's property with the key Exchange.CHARSET_NAME, or setting the encoding property on Xstream from DSL or Spring config. from("activemq:My.Queue"). marshal().xstream("UTF-8"). to("mqseries:Another.Queue"); <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <!-- we define the json xstream data formats to be used (xstream is default) --> <dataFormats> <xstream id="xstream-utf8" encoding="UTF-8"/> <xstream id="xstream-default"/> </dataFormats> <route> <from uri="direct:in"/> <marshal ref="xstream-default"/> <to uri="mock:result"/> </route> <route> <from uri="direct:in-UTF-8"/> <marshal ref="xstream-utf8"/> <to uri="mock:result"/> </route> </camelContext> DependenciesTo use XStream in your camel routes you need to add the a dependency on camel-xstream which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-xstream</artifactId> <version>1.5.0</version> </dependency> CSVThe CSV Data Format uses Apache Commons CSV to handle CSV payloads (Comma Separated Values) such as those exported/imported by Excel. Options
Marshalling a Map to CSVThe component allows you to marshal a Java Map (or any other message type that can be converted in a Map) into a CSV payload. An example: if you send a message with this map... Map<String, Object> body = new HashMap<String, Object>(); body.put("foo", "abc"); body.put("bar", 123); ... through this route ... from("direct:start"). marshal().csv(). to("mock:result"); ... you will end up with a String containing this CSV message abc,123 Sending the Map below through this route will result in a CSV message that looks like foo,bar Unmarshalling a CSV message into a Java ListUnmarshalling will transform a CSV messsage into a Java List with CSV file lines (containing another List with all the field values). An example: we have a CSV file with names of persons, their IQ and their current activity. Jack Dalton, 115, mad at Averell
Joe Dalton, 105, calming Joe
William Dalton, 105, keeping Joe from killing Averell
Averell Dalton, 80, playing with Rantanplan
Lucky Luke, 120, capturing the Daltons
We can now use the CSV component to unmarshal this file: from("file:src/test/resources/?fileName=daltons.csv&noop=true"). unmarshal().csv(). to("mock:daltons"); The resulting message will contain a List<List<String>> like... List<List<String>> data = (List<List<String>>) exchange.getIn().getBody(); for (List<String> line : data) { LOG.debug(String.format("%s has an IQ of %s and is currently %s", line.get(0), line.get(1), line.get(2))); } Marshalling a List<Map> to CSVAvailable as of Camel 2.1 If you have multiple rows of data you want to be marshalled into CSV format you can now store the message payload as a List<Map<String, Object>> object where the list contains a Map for each row. File Poller of CSV, then unmarshalingGiven a bean which can handle the incoming data... MyCsvHandler.java // Some comments here public void doHandleCsvData(List<List<String>> csvData) { // do magic here } ... your route then looks as follows <route> <!-- poll every 10 seconds --> <from uri="file:///some/path/to/pickup/csvfiles?delete=true&consumer.delay=10000" /> <unmarshal><csv /></unmarshal> <to uri="bean:myCsvHandler?method=doHandleCsvData" /> </route> Marshaling with a pipe as delimiterUsing the Spring/XML DSL: <route> <from uri="direct:start" /> <marshal> <csv delimiter="|" /> </marshal> <to uri="bean:myCsvHandler?method=doHandleCsv" /> </route> Or the Java DSL: CsvDataFormat csv = new CsvDataFormat(); CSVConfig config = new CSVConfig(); config.setDelimiter('|'); csv.setConfig(config); from("direct:start") .marshal(csv) .convertBodyTo(String.class) .to("bean:myCsvHandler?method=doHandleCsv"); CsvDataFormat csv = new CsvDataFormat(); csv.setDelimiter("|"); from("direct:start") .marshal(csv) .convertBodyTo(String.class) .to("bean:myCsvHandler?method=doHandleCsv"); Unmarshaling with a pipe as delimiterUsing the Spring/XML DSL: <route> <from uri="direct:start" /> <unmarshal> <csv delimiter="|" /> </unmarshal> <to uri="bean:myCsvHandler?method=doHandleCsv" /> </route> Or the Java DSL: CsvDataFormat csv = new CsvDataFormat(); CSVStrategy strategy = CSVStrategy.DEFAULT_STRATEGY; strategy.setDelimiter('|'); csv.setStrategy(strategy); from("direct:start") .unmarshal(csv) .to("bean:myCsvHandler?method=doHandleCsv"); CsvDataFormat csv = new CsvDataFormat(); csv.setDelimiter("|"); from("direct:start") .unmarshal(csv) .to("bean:myCsvHandler?method=doHandleCsv"); DependenciesTo use CSV in your camel routes you need to add the a dependency on camel-csv which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-csv</artifactId> <version>2.0.0</version> </dependency> The String Data Format is a textual based format that supports encoding. Options
MarshalIn this example we marshal the file content to String object in UTF-8 encoding.
from("file://data.csv").marshal().string("UTF-8").to("jms://myqueue");
UnmarshalIn this example we unmarshal the payload from the JMS queue to a String object using UTF-8 encoding, before its processed by the newOrder processor.
from("jms://queue/order").unmarshal().string("UTF-8").processRef("newOrder");
DependenciesThis data format is provided in camel-core so no additional dependencies is needed. HL7 DataFormatThe HL7 component ships with a HL7 data format that can be used to format between String and HL7 model objects.
To use the data format, simply instantiate an instance and invoke the marhsal or unmarshl operation in the route builder: DataFormat hl7 = new HL7DataFormat(); ... from("direct:hl7in").marshal(hl7).to("jms:queue:hl7out"); In the sample above, the HL7 is marshalled from a HAPI Message object to a byte stream and put on a JMS queue. DataFormat hl7 = new HL7DataFormat(); ... from("jms:queue:hl7out").unmarshal(hl7).to("patientLookupService"); Here we unmarshal the byte stream into a HAPI Message object that is passed to our patient lookup service. Notice there is a shorthand syntax in Camel for well-known data formats that is commonly used. from("direct:hl7in").marshal().hl7().to("jms:queue:hl7out"); from("jms:queue:hl7out").unmarshal().hl7().to("patientLookupService"); EDI DataFormatWe encourage end users to look at the Smooks which supports EDI and Camel natively. Flatpack DataFormatThe Flatpack component ships with the Flatpack data format that can be used to format between fixed width or delimited text messages to a List of rows as Map.
Notice: The Flatpack library does currently not support header and trailers for the marshal operation. OptionsThe data format has the following options:
UsageTo use the data format, simply instantiate an instance and invoke the marhsal or unmarshal operation in the route builder: FlatpackDataFormat fp = new FlatpackDataFormat(); fp.setDefinition(new ClassPathResource("INVENTORY-Delimited.pzmap.xml")); ... from("file:order/in").unmarshal(df).to("seda:queue:neworder"); The sample above will read files from the order/in folder and unmarshal the input using the Flatpack configuration file INVENTORY-Delimited.pzmap.xml that configures the structure of the files. The result is a DataSetList object we store on the SEDA queue. FlatpackDataFormat df = new FlatpackDataFormat(); df.setDefinition(new ClassPathResource("PEOPLE-FixedLength.pzmap.xml")); df.setFixed(true); df.setIgnoreFirstRecord(false); from("seda:people").marshal(df).convertBodyTo(String.class).to("jms:queue:people"); In the code above we marshal the data from a Object representation as a List of rows as Maps. The rows as Map contains the column name as the key, and the the corresponding value. This structure can be created in Java code from e.g. a processor. We marshal the data according to the Flatpack format and convert the result as a String object and store it on a JMS queue. DependenciesTo use Flatpack in your camel routes you need to add the a dependency on camel-flatpack which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-flatpack</artifactId> <version>1.5.0</version> </dependency> JSONJSON is a Data Format to marshal and unmarshal Java objects to and from JSON. In Camel 1.6 its only the XStream library that is supported and its default. In Camel 2.0 we added support for more libraries:
By default Camel uses the XStream library. Using JSon data format with the XStream library// lets turn Object messages into json then send to MQSeries from("activemq:My.Queue"). marshal().json(). to("mqseries:Another.Queue"); Using Json data format with the Jackson library// lets turn Object messages into json then send to MQSeries from("activemq:My.Queue"). marshal().json(JsonLibrary.Jackson). to("mqseries:Another.Queue"); Using Json data format with the GSON library// lets turn Object messages into json then send to MQSeries from("activemq:My.Queue"). marshal().json(JsonLibrary.Gson). to("mqseries:Another.Queue"); Using Json in Spring DSLWhen using Data Format in Spring DSL you need to declare the data formats first. This is done in the DataFormats XML tag.
<dataFormats>
<!-- here we define a Json data format with the id jack and that it should use the TestPojo as the class type when
doing unmarshal. The unmarshalTypeName is optional, if not provided Camel will use a Map as the type -->
<json id="jack" library="Jackson" unmarshalTypeName="org.apache.camel.component.jackson.TestPojo"/>
</dataFormats>
And then you can refer to this id in the route:
<route>
<from uri="direct:back"/>
<unmarshal ref="jack"/>
<to uri="mock:reverse"/>
</route>
Dependencies for XStreamTo use JSON in your camel routes you need to add the a dependency on camel-xstream which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-xstream</artifactId> <version>2.0</version> </dependency> Dependencies for JacksonTo use JSON in your camel routes you need to add the a dependency on camel-jackson which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jackson</artifactId> <version>2.0</version> </dependency> Dependencies for GSONTo use JSON in your camel routes you need to add the a dependency on camel-gson which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-gson</artifactId> <version>2.10</version> </dependency> The Zip Data Format is a message compression and de-compression format. Messages marshalled using Zip compression can be unmarshalled using Zip decompression just prior to being consumed at the endpoint. The compression capability is quite useful when you deal with large XML and Text based payloads. It facilitates more optimal use of network bandwidth while incurring a small cost in order to compress and decompress payloads at the endpoint.
Options
MarshalIn this example we marshal a regular text/XML payload to a compressed payload employing zip compression Deflater.BEST_COMPRESSION and send it an ActiveMQ queue called MY_QUEUE. from("direct:start").marshal().zip(Deflater.BEST_COMPRESSION).to("activemq:queue:MY_QUEUE"); Alternatively if you would like to use the default setting you could send it as from("direct:start").marshal().zip().to("activemq:queue:MY_QUEUE"); UnmarshalIn this example we unmarshal a zipped payload from an ActiveMQ queue called MY_QUEUE to its original format, and forward it for processing to the UnZippedMessageProcessor. Note that the compression Level employed during the marshalling should be identical to the one employed during unmarshalling to avoid errors. from("activemq:queue:MY_QUEUE").unmarshal().zip().process(new UnZippedMessageProcessor()); DependenciesThis data format is provided in camel-core so no additional dependencies is needed. TidyMarkupTidyMarkup is a Data Format that uses the TagSoup to tidy up HTML. It can be used to parse ugly HTML and return it as pretty wellformed HTML.
TidyMarkup only supports the unmarshal operation as we really don't want to turn well formed HTML into ugly HTML Java DSL ExampleAn example where the consumer provides some HTML
from("file://site/inbox").unmarshal().tidyMarkup().to("file://site/blogs");
Spring XML ExampleThe following example shows how to use TidyMarkup to unmarshal using Spring <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="file://site/inbox"/> <unmarshal> <tidyMarkup/> </unmarshal> <to uri="file://site/blogs"/> </route> </camelContext> DependenciesTo use TidyMarkup in your camel routes you need to add the a dependency on camel-tagsoup which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-tagsoup</artifactId> <version>1.6.0</version> </dependency> BindyAvailable as of Camel 2.0 The idea that the developers has followed to design this component was to allow the parsing/binding of non structured data (or to be more precise non-XML data)
to one or many Plain Old Java Object (POJO) and to convert the data according to the type of the java property. POJO can be linked together and relation one to many is available in some cases. Moreover, for data type like Date, Double, Float, Integer, Short, Long and BigDecimal, you can provide the pattern to apply during the formatting of the property. For the BigDecimal number, you can also define the precision and the decimal or grouping separators
Decimal* = Double, Integer, Float, Short, Long
To work with camel-bindy, you must first define your model in a package (e.g. com.acme.model) and for each model class (e.g. Order, Client, Instrument, ...) associate the required annotations (described hereafter) with Class or property name. AnnotationsThe annotations created allow to map different concept of your model to the POJO like :
This section will describe them : 1. CsvRecordThe CsvRecord annotation is used to identified the root class of the model. It represents a record = a line of a CSV file and can be linked to several children model classes.
case 1 : separator = ',' The separator used to segregate the fields in the CSV record is ',' : 10, J, Pauline, M, XD12345678, Fortis Dynamic 15/15, 2500, USD,08-01-2009 @CsvRecord( separator = "," ) public Class Order { ... } case 2 : separator = ';' Compare to the previous case, the separator here is ';' instead of ',' : 10; J; Pauline; M; XD12345678; Fortis Dynamic 15/15; 2500; USD; 08-01-2009 @CsvRecord( separator = ";" ) public Class Order { ... } case 3 : separator = '|' Compare to the previous case, the separator here is '|' instead of ';' : 10| J| Pauline| M| XD12345678| Fortis Dynamic 15/15| 2500| USD| 08-01-2009 @CsvRecord( separator = "\\|" ) public Class Order { ... } case 4 : separator = '\",\"' When the field to be parsed of the CSV record contains ',' or ';' which is also used as separator, we whould find another strategy "10","J","Pauline"," M","XD12345678","Fortis Dynamic 15,15" 2500","USD","08-01-2009" @CsvRecord( separator = "\",\"" ) public Class Order { ... } From Camel 2.8.3/2.9 or never bindy will automatic detect if the record is enclosed with either single or double quotes and automatic remove those quotes when unmarshalling from CSV to Object. Therefore do not include the quotes in the separator, but simple do as below: "10","J","Pauline"," M","XD12345678","Fortis Dynamic 15,15" 2500","USD","08-01-2009" @CsvRecord( separator = "," ) public Class Order { ... } Notice that if you want to marshal from Object to CSV and use quotes, then you need to specify which quote character to use, using the quote attribute on the @CsvRecord as shown below: @CsvRecord( separator = ",", quote = "\"" ) public Class Order { ... } case 5 : separator & skipfirstline The feature is interesting when the client wants to have in the first line of the file, the name of the data fields : order id, client id, first name, last name, isin code, instrument name, quantity, currency, date To inform bindy that this first line must be skipped during the parsing process, then we use the attribute : @CsvRecord(separator = ",", skipFirstLine = true) public Class Order { ... } case 6 : generateHeaderColumns To add at the first line of the CSV generated, the attribute generateHeaderColumns must be set to true in the annotation like this : @CsvRecord( generateHeaderColumns = true ) public Class Order { ... } As a result, Bindy during the unmarshaling process will generate CSV like this : order id, client id, first name, last name, isin code, instrument name, quantity, currency, date case 7 : carriage return If the platform where camel-bindy will run is not Windows but Macintosh or Unix, than you can change the crlf property like this. Three values are available : WINDOWS, UNIX or MAC @CsvRecord(separator = ",", crlf="MAC") public Class Order { ... } case 8 : isOrdered Sometimes, the order to follow during the creation of the CSV record from the model is different from the order used during the parsing. Then, in this case, we can use the attribute isOrdered = true to indicate this in combination with attribute 'position' of the DataField annotation. @CsvRecord(isOrdered = true) public Class Order { @DataField(pos = 1, position = 11) private int orderNr; @DataField(pos = 2, position = 10) private String clientNr; ... } Remark : pos is used to parse the file, stream while positions is used to generate the CSV 2. LinkThe link annotation will allow to link objects together.
e.g : If the model Class Client is linked to the Order class, then use annotation Link in the Order class like this : Property Link @CsvRecord(separator = ",") public class Order { @DataField(pos = 1) private int orderNr; @Link private Client client; ... AND for the class Client : Class Link
@Link
public class Client {
...
}
3. DataFieldThe DataField annotation defines the property of the field. Each datafield is identified by its position in the record, a type (string, int, date, ...) and optionally of a pattern
case 1 : pos This parameter/attribute represents the position of the field in the csv record Position @CsvRecord(separator = ",") public class Order { @DataField(pos = 1) private int orderNr; @DataField(pos = 5) private String isinCode; ... } As you can see in this example the position starts at '1' but continues at '5' in the class Order. The numbers from '2' to '4' are defined in the class Client (see here after). Position continues in another model class public class Client { @DataField(pos = 2) private String clientNr; @DataField(pos = 3) private String firstName; @DataField(pos = 4) private String lastName; ... } case 2 : pattern The pattern allows to enrich or validates the format of your data Pattern @CsvRecord(separator = ",") public class Order { @DataField(pos = 1) private int orderNr; @DataField(pos = 5) private String isinCode; @DataField(name = "Name", pos = 6) private String instrumentName; @DataField(pos = 7, precision = 2) private BigDecimal amount; @DataField(pos = 8) private String currency; @DataField(pos = 9, pattern = "dd-MM-yyyy") -- pattern used during parsing or when the date is created private Date orderDate; ... } case 3 : precision The precision is helpful when you want to define the decimal part of your number Precision @CsvRecord(separator = ",") public class Order { @DataField(pos = 1) private int orderNr; @Link private Client client; @DataField(pos = 5) private String isinCode; @DataField(name = "Name", pos = 6) private String instrumentName; @DataField(pos = 7, precision = 2) -- precision private BigDecimal amount; @DataField(pos = 8) private String currency; @DataField(pos = 9, pattern = "dd-MM-yyyy") private Date orderDate; ... } case 4 : Position is different in output The position attribute will inform bindy how to place the field in the CSV record generated. By default, the position used corresponds to the position defined with the attribute 'pos'. If the position is different (that means that we have an asymetric processus comparing marshaling from unmarshaling) than we can use 'position' to indicate this. Here is an example Position is different in output @CsvRecord(separator = ",") public class Order { @CsvRecord(separator = ",", isOrdered = true) public class Order { // Positions of the fields start from 1 and not from 0 @DataField(pos = 1, position = 11) private int orderNr; @DataField(pos = 2, position = 10) private String clientNr; @DataField(pos = 3, position = 9) private String firstName; @DataField(pos = 4, position = 8) private String lastName; @DataField(pos = 5, position = 7) private String instrumentCode; @DataField(pos = 6, position = 6) private String instrumentNumber; ... }
case 5 : required If a field is mandatory, simply use the attribute 'required' setted to true Required @CsvRecord(separator = ",") public class Order { @DataField(pos = 1) private int orderNr; @DataField(pos = 2, required = true) private String clientNr; @DataField(pos = 3, required = true) private String firstName; @DataField(pos = 4, required = true) private String lastName; ... } If this field is not present in the record, than an error will be raised by the parser with the following information : Some fields are missing (optional or mandatory), line : case 6 : trim If a field has leading and/or trailing spaces which should be removed before they are processed, simply use the attribute 'trim' setted to true Trim @CsvRecord(separator = ",") public class Order { @DataField(pos = 1, trim = true) private int orderNr; @DataField(pos = 2, trim = true) private Integer clientNr; @DataField(pos = 3, required = true) private String firstName; @DataField(pos = 4) private String lastName; ... } 4. FixedLengthRecordThe FixedLengthRecord annotation is used to identified the root class of the model. It represents a record = a line of a file/message containing data fixed length formatted
case 1 : Simple fixed length record This simple example shows how to design the model to parse/format a fixed message 10A9PaulineMISINXD12345678BUYShare2500.45USD01-08-2009 Fixed-simple
@FixedLengthRecord(length=54, paddingChar=' ')
public static class Order {
@DataField(pos = 1, length=2)
private int orderNr;
@DataField(pos = 3, length=2)
private String clientNr;
@DataField(pos = 5, length=7)
private String firstName;
@DataField(pos = 12, length=1, align="L")
private String lastName;
@DataField(pos = 13, length=4)
private String instrumentCode;
@DataField(pos = 17, length=10)
private String instrumentNumber;
@DataField(pos = 27, length=3)
private String orderType;
@DataField(pos = 30, length=5)
private String instrumentType;
@DataField(pos = 35, precision = 2, length=7)
private BigDecimal amount;
@DataField(pos = 42, length=3)
private String currency;
@DataField(pos = 45, length=10, pattern = "dd-MM-yyyy")
private Date orderDate;
...
case 2 : Fixed length record with alignment and padding This more elaborated example show how to define the alignment for a field and how to assign a padding character which is ' ' here'' 10A9 PaulineM ISINXD12345678BUYShare2500.45USD01-08-2009 Fixed-padding-align
@FixedLengthRecord(length=60, paddingChar=' ')
public static class Order {
@DataField(pos = 1, length=2)
private int orderNr;
@DataField(pos = 3, length=2)
private String clientNr;
@DataField(pos = 5, length=9)
private String firstName;
@DataField(pos = 14, length=5, align="L") // align text to the LEFT zone of the block
private String lastName;
@DataField(pos = 19, length=4)
private String instrumentCode;
@DataField(pos = 23, length=10)
private String instrumentNumber;
@DataField(pos = 33, length=3)
private String orderType;
@DataField(pos = 36, length=5)
private String instrumentType;
@DataField(pos = 41, precision = 2, length=7)
private BigDecimal amount;
@DataField(pos = 48, length=3)
private String currency;
@DataField(pos = 51, length=10, pattern = "dd-MM-yyyy")
private Date orderDate;
...
case 3 : Field padding Sometimes, the default padding defined for record cannnot be applied to the field as we have a number format where we would like to padd with '0' instead of ' '. In this case, you can use in the model the attribute paddingField to set this value. 10A9 PaulineM ISINXD12345678BUYShare000002500.45USD01-08-2009 Fixed-padding-field
@FixedLengthRecord(length = 65, paddingChar = ' ')
public static class Order {
@DataField(pos = 1, length = 2)
private int orderNr;
@DataField(pos = 3, length = 2)
private String clientNr;
@DataField(pos = 5, length = 9)
private String firstName;
@DataField(pos = 14, length = 5, align = "L")
private String lastName;
@DataField(pos = 19, length = 4)
private String instrumentCode;
@DataField(pos = 23, length = 10)
private String instrumentNumber;
@DataField(pos = 33, length = 3)
private String orderType;
@DataField(pos = 36, length = 5)
private String instrumentType;
@DataField(pos = 41, precision = 2, length = 12, paddingChar = '0')
private BigDecimal amount;
@DataField(pos = 53, length = 3)
private String currency;
@DataField(pos = 56, length = 10, pattern = "dd-MM-yyyy")
private Date orderDate;
...
5. MessageThe Message annotation is used to identified the class of your model who will contain key value pairs fields. This kind of format is used mainly in Financial Exchange Protocol Messages (FIX). Nevertheless, this annotation can be used for any other format where data are identified by keys. The key pair values are separated each other by a separator which can be a special character like a tab delimitor (unicode representation : \u0009) or a start of heading (unicode representation : \u0001)
case 1 : separator = 'u0001' The separator used to segregate the key value pair fields in a FIX message is the ASCII '01' character or in unicode format '\u0001'. This character must be escaped a second time to avoid a java runtime error. Here is an example : 8=FIX.4.1 9=20 34=1 35=0 49=INVMGR 56=BRKR 1=BE.CHM.001 11=CHM0001-01 22=4 ... and how to use the annotation FIX - message @Message(keyValuePairSeparator = "=", pairSeparator = "\u0001", type="FIX", version="4.1") public class Order { ... }
6. KeyValuePairFieldThe KeyValuePairField annotation defines the property of a key value pair field. Each KeyValuePairField is identified by a tag (= key) and its value associated, a type (string, int, date, ...), optionaly a pattern and if the field is required
case 1 : tag This parameter represents the key of the field in the message FIX message - Tag @Message(keyValuePairSeparator = "=", pairSeparator = "\u0001", type="FIX", version="4.1") public class Order { @Link Header header; @Link Trailer trailer; @KeyValuePairField(tag = 1) // Client reference private String Account; @KeyValuePairField(tag = 11) // Order reference private String ClOrdId; @KeyValuePairField(tag = 22) // Fund ID type (Sedol, ISIN, ...) private String IDSource; @KeyValuePairField(tag = 48) // Fund code private String SecurityId; @KeyValuePairField(tag = 54) // Movement type ( 1 = Buy, 2 = sell) private String Side; @KeyValuePairField(tag = 58) // Free text private String Text; ... } case 2 : Different position in output If the tags/keys that we will put in the FIX message must be sorted according to a predefine order, then use the attribute 'position' of the annotation @KeyValuePairField FIX message - Tag - sort @Message(keyValuePairSeparator = "=", pairSeparator = "\\u0001", type = "FIX", version = "4.1", isOrdered = true) public class Order { @Link Header header; @Link Trailer trailer; @KeyValuePairField(tag = 1, position = 1) // Client reference private String account; @KeyValuePairField(tag = 11, position = 3) // Order reference private String clOrdId; ... } 7. SectionIn FIX message of fixed length records, it is common to have different sections in the representation of the information : header, body and section. The purpose of the annotation @Section is to inform bindy about which class of the model represents the header (= section 1), body (= section 2) and footer (= section 3) Only one attribute/parameter exists for this annotation.
case 1 : Section A. Definition of the header section FIX message - Section - Header @Section(number = 1) public class Header { @KeyValuePairField(tag = 8, position = 1) // Message Header private String beginString; @KeyValuePairField(tag = 9, position = 2) // Checksum private int bodyLength; ... } B. Definition of the body section FIX message - Section - Body @Section(number = 2) @Message(keyValuePairSeparator = "=", pairSeparator = "\\u0001", type = "FIX", version = "4.1", isOrdered = true) public class Order { @Link Header header; @Link Trailer trailer; @KeyValuePairField(tag = 1, position = 1) // Client reference private String account; @KeyValuePairField(tag = 11, position = 3) // Order reference private String clOrdId; C. Definition of the footer section FIX message - Section - Footer @Section(number = 3) public class Trailer { @KeyValuePairField(tag = 10, position = 1) // CheckSum private int checkSum; public int getCheckSum() { return checkSum; } 8. OneToManyThe purpose of the annotation @OneToMany is to allow to work with a List<?> field defined a POJO class or from a record containing repetitive groups.
The relation OneToMany ONLY WORKS in the following cases :
case 1 : Generating CSV with repetitive data Here is the CSV output that we want : Claus,Ibsen,Camel in Action 1,2010,35 Remark : the repetitive data concern the title of the book and its publication date while first, last name and age are common and the classes used to modeling this. The Author class contains a List of Book. Generate CSV with repetitive data @CsvRecord(separator=",") public class Author { @DataField(pos = 1) private String firstName; @DataField(pos = 2) private String lastName; @OneToMany private List<Book> books; @DataField(pos = 5) private String Age; ... public class Book { @DataField(pos = 3) private String title; @DataField(pos = 4) private String year; Very simple isn't it !!! case 2 : Reading FIX message containing group of tags/keys Here is the message that we would like to process in our model : "8=FIX 4.19=2034=135=049=INVMGR56=BRKR" tags 22, 48 and 54 are repeated and the code Reading FIX message containing group of tags/keys public class Order { @Link Header header; @Link Trailer trailer; @KeyValuePairField(tag = 1) // Client reference private String account; @KeyValuePairField(tag = 11) // Order reference private String clOrdId; @KeyValuePairField(tag = 58) // Free text private String text; @OneToMany(mappedTo = "org.apache.camel.dataformat.bindy.model.fix.complex.onetomany.Security") List<Security> securities; ... public class Security { @KeyValuePairField(tag = 22) // Fund ID type (Sedol, ISIN, ...) private String idSource; @KeyValuePairField(tag = 48) // Fund code private String securityCode; @KeyValuePairField(tag = 54) // Movement type ( 1 = Buy, 2 = sell) private String side; Using the Java DSLThe next step consists in instantiating the DataFormat bindy class associated with this record type and providing Java package name(s) as parameter. For example the following uses the class CsvBindyFormat (who correspond to the class associated with the CSV record type) which is configured with "com.acme.model" DataFormat bindy = new CsvBindyDataFormat("com.acme.model"); from("file://inbox"). unmarshal(bindy). to("bean:handleOrder"); The Camel route will pick-up files in the inbox directory, unmarshall CSV records in a collection of model objects and send the collection The collection is a list of Map. Each Map of the list contains the objects of the model. Each object can be retrieve using its class name. int count = 0; List<Map<String, Object>> models = new ArrayList<Map<String, Object>>(); Map<String, Object> model = new HashMap<String, Object>(); models = (List<Map<String, Object>>) exchange.getIn().getBody(); Iterator<Map<String, Object>> it = models.iterator(); while(it.hasNext()){ model = it.next(); for(String key : model.keySet()) { Object obj = model.get(key); LOG.info("Count : " + count + ", " + obj.toString()); } count++; } LOG.info("Nber of CSV records received by the csv bean : " + count); To generate CSV records from a collection of model objects, you create the following route : from("bean:handleOrder") marshal(bindy) to("file://outbox") You can if you prefer use a named reference to a data format which can then be defined in your Registry such as via your Spring XML file. e.g. from("file://inbox"). unmarshal("myBindyDataFormat"). to("bean:handleOrder"); Unit testHere is two examples showing how to marshall or unmarshall a CSV file with Camel Marshall package org.apache.camel.dataformat.bindy.csv; import java.math.BigDecimal; import java.util.ArrayList; import java.util.Calendar; import java.util.GregorianCalendar; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.camel.EndpointInject; import org.apache.camel.Produce; import org.apache.camel.ProducerTemplate; import org.apache.camel.builder.RouteBuilder; import org.apache.camel.component.mock.MockEndpoint; import org.apache.camel.dataformat.bindy.model.complex.twoclassesandonelink.Client; import org.apache.camel.dataformat.bindy.model.complex.twoclassesandonelink.Order; import org.apache.camel.spring.javaconfig.SingleRouteCamelConfiguration; import org.junit.Test; import org.springframework.config.java.annotation.Bean; import org.springframework.config.java.annotation.Configuration; import org.springframework.config.java.test.JavaConfigContextLoader; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests; @ContextConfiguration(locations = "org.apache.camel.dataformat.bindy.csv.BindyComplexCsvMarshallTest$ContextConfig", loader = JavaConfigContextLoader.class) public class BindyComplexCsvMarshallTest extends AbstractJUnit4SpringContextTests { private List<Map<String, Object>> models = new ArrayList<Map<String, Object>>(); private String result = "10,A1,Julia,Roberts,BE123456789,Belgium Ventage 10/12,150,USD,14-01-2009"; @Produce(uri = "direct:start") private ProducerTemplate template; @EndpointInject(uri = "mock:result") private MockEndpoint resultEndpoint; @Test public void testMarshallMessage() throws Exception { resultEndpoint.expectedBodiesReceived(result); template.sendBody(generateModel()); resultEndpoint.assertIsSatisfied(); } private List<Map<String, Object>> generateModel() { Map<String, Object> model = new HashMap<String, Object>(); Order order = new Order(); order.setOrderNr(10); order.setAmount(new BigDecimal("150")); order.setIsinCode("BE123456789"); order.setInstrumentName("Belgium Ventage 10/12"); order.setCurrency("USD"); Calendar calendar = new GregorianCalendar(); calendar.set(2009, 0, 14); order.setOrderDate(calendar.getTime()); Client client = new Client(); client.setClientNr("A1"); client.setFirstName("Julia"); client.setLastName("Roberts"); order.setClient(client); model.put(order.getClass().getName(), order); model.put(client.getClass().getName(), client); models.add(0, model); return models; } @Configuration public static class ContextConfig extends SingleRouteCamelConfiguration { BindyCsvDataFormat camelDataFormat = new BindyCsvDataFormat("org.apache.camel.dataformat.bindy.model.complex.twoclassesandonelink"); @Override @Bean public RouteBuilder route() { return new RouteBuilder() { @Override public void configure() { from("direct:start").marshal(camelDataFormat).to("mock:result"); } }; } } } Unmarshall package org.apache.camel.dataformat.bindy.csv; import org.apache.camel.EndpointInject; import org.apache.camel.builder.RouteBuilder; import org.apache.camel.component.mock.MockEndpoint; import org.apache.camel.spring.javaconfig.SingleRouteCamelConfiguration; import org.junit.Test; import org.springframework.config.java.annotation.Bean; import org.springframework.config.java.annotation.Configuration; import org.springframework.config.java.test.JavaConfigContextLoader; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests; @ContextConfiguration(locations = "org.apache.camel.dataformat.bindy.csv.BindyComplexCsvUnmarshallTest$ContextConfig", loader = JavaConfigContextLoader.class) public class BindyComplexCsvUnmarshallTest extends AbstractJUnit4SpringContextTests { @EndpointInject(uri = "mock:result") private MockEndpoint resultEndpoint; @Test public void testUnMarshallMessage() throws Exception { resultEndpoint.expectedMessageCount(1); resultEndpoint.assertIsSatisfied(); } @Configuration public static class ContextConfig extends SingleRouteCamelConfiguration { BindyCsvDataFormat csvBindyDataFormat = new BindyCsvDataFormat("org.apache.camel.dataformat.bindy.model.complex.twoclassesandonelink"); @Override @Bean public RouteBuilder route() { return new RouteBuilder() { @Override public void configure() { from("file://src/test/data?noop=true").unmarshal(csvBindyDataFormat).to("mock:result"); } }; } } } In this example, BindyCsvDataFormat class has been instantiated in a traditional way but it is also possible to provide information directly to the function (un)marshal like this where BindyType corresponds to the Bindy DataFormat class to instantiate and the parameter contains the list of package names.
public static class ContextConfig extends SingleRouteCamelConfiguration {
@Override
@Bean
public RouteBuilder route() {
return new RouteBuilder() {
@Override
public void configure() {
from("direct:start")
.marshal().bindy(BindyType.Csv, "org.apache.camel.dataformat.bindy.model.simple.oneclass")
.to("mock:result");
}
};
}
}
Using Spring XMLThis is really easy to use Spring as your favorite DSL language to declare the routes to be used for camel-bindy. The following example shows two routes where the first will pick-up records from files, unmarshal the content and bind it to their model. The result is then send to a pojo (doing nothing special) and place them into a queue. The second route will extract the pojos from the queue and marshal the content to generate a file containing the csv record spring dsl <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <bean id="bindyDataformat" class="org.apache.camel.dataformat.bindy.csv.BindyCsvDataFormat"> <constructor-arg value="org.apache.camel.bindy.model" /> </bean> <bean id="csv" class="org.apache.camel.bindy.csv.HandleOrderBean" /> <!-- Queuing engine - ActiveMq - work locally in mode virtual memory --> <bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="brokerURL" value="vm://localhost:61616"/> </bean> <camelContext xmlns="http://camel.apache.org/schema/spring"> <jmxAgent id="agent" disabled="false" /> <route> <from uri="file://src/data/csv/?noop=true" /> <unmarshal ref="bindyDataformat" /> <to uri="bean:csv" /> <to uri="activemq:queue:in" /> </route> <route> <from uri="activemq:queue:in" /> <marshal ref="bindyDataformat" /> <to uri="file://src/data/csv/out/" /> </route> </camelContext> </beans>
DependenciesTo use Bindy in your camel routes you need to add the a dependency on camel-bindy which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-bindy</artifactId> <version>2.1.0</version> </dependency> XMLSecurity Data FormatAvailable as of Camel 2.0 The XMLSecurity DataFormat facilitates encryption and decryption of XML payloads at the Document, Element and Element Content levels (including simultaneous multi-node encryption/decryption using XPATH). The encryption capability is based on formats supported using the Apache XML Security (Santaurio) project. Symmetric encryption/cecryption is currently supported using Triple-DES and AES (128, 192 and 256) encryption formats. Additional formats can be easily added later as needed. Available as of Camel 2.9 The XMLSecurity DataFormat also has improved support for namespaces when processing the XPath queries that select content for encryption. A namespace definition mapping can be included as part of the data format configuration. This enables true namespace matching, even if the prefix values in the XPath query and the target xml document are not equivalent strings. Basic Options
Asymmetric Encryption OptionsThese options can be applied in addition to relevant the Basic options to use asymmetric key encryption.
MarshalIn order to encrypt the payload, the marshal processor needs to be applied on the route followed by the secureXML() tag. UnmarshalIn order to decrypt the payload, the unmarshal processor needs to be applied on the route followed by the secureXML() tag. ExamplesGiven below are several examples of how marshalling could be performaed at the Document, Element and Content levels. Full Payload encryption/decryptionfrom("direct:start"). marshal().secureXML(). unmarshal().secureXML(). to("direct:end"); Partial Payload Content Only encryption/decryption*String tagXPATH = "//cheesesites/italy/cheese"; boolean secureTagContent = true; ... from("direct:start"). marshal().secureXML(tagXPATH , secureTagContent ). unmarshal().secureXML(tagXPATH , secureTagContent). to("direct:end"); Partial Multi Node Payload Content Only encryption/decryption*String tagXPATH = "//cheesesites/*/cheese"; boolean secureTagContent = true; .... from("direct:start"). marshal().secureXML(tagXPATH , secureTagContent ). unmarshal().secureXML(tagXPATH , secureTagContent). to("direct:end"); Partial Payload Content Only encryption/decryption with choice of passPhrase(password)*String tagXPATH = "//cheesesites/italy/cheese"; boolean secureTagContent = true; .... String passPhrase = "Just another 24 Byte key"; from("direct:start"). marshal().secureXML(tagXPATH , secureTagContent , passPhrase). unmarshal().secureXML(tagXPATH , secureTagContent, passPhrase). to("direct:end"); Partial Payload Content Only encryption/decryption with passPhrase(password) and Algorithm*import org.apache.xml.security.encryption.XMLCipher; .... String tagXPATH = "//cheesesites/italy/cheese"; boolean secureTagContent = true; String passPhrase = "Just another 24 Byte key"; String algorithm= XMLCipher.TRIPLEDES; from("direct:start"). marshal().secureXML(tagXPATH , secureTagContent , passPhrase, algorithm). unmarshal().secureXML(tagXPATH , secureTagContent, passPhrase, algorithm). to("direct:end"); Partial Paryload Content with Namespace supportJava DSLfinal Map<String, String> namespaces = new HashMap<String, String>(); namespaces.put("cust", "http://cheese.xmlsecurity.camel.apache.org/"); final KeyStoreParameters tsParameters = new KeyStoreParameters(); tsParameters.setPassword("password"); tsParameters.setResource("sender.ts"); context.addRoutes(new RouteBuilder() { public void configure() { from("direct:start") .marshal().secureXML("//cust:cheesesites/italy", namespaces, true, "recipient", testCypherAlgorithm, XMLCipher.RSA_v1dot5, tsParameters).to("mock:encrypted"); } } Spring XMLA namespace prefix that is defined as part of the camelContext definition can be re-used in context within the data format secureTag attribute of the secureXML element.
<camelContext id="springXmlSecurityDataFormatTestCamelContext"
xmlns="http://camel.apache.org/schema/spring"
xmlns:cheese="http://cheese.xmlsecurity.camel.apache.org/">
<route>
<from uri="direct://start"/>
<marshal>
<secureXML
secureTag="//cheese:cheesesites/italy"
secureTagContents="true" />
</marshal>
...
Asymmetric Key EncryptionSpring XML Sender
<!-- trust store configuration -->
<camel:keyStoreParameters id="trustStoreParams" resource="./sender.ts" password="password"/>
<camelContext id="springXmlSecurityDataFormatTestCamelContext"
xmlns="http://camel.apache.org/schema/spring"
xmlns:cheese="http://cheese.xmlsecurity.camel.apache.org/">
<route>
<from uri="direct://start"/>
<marshal>
<secureXML
secureTag="//cheese:cheesesites/italy"
secureTagContents="true"
xmlCipherAlgorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"
keyCipherAlgorithm="http://www.w3.org/2001/04/xmlenc#rsa-1_5"
recipientKeyAlias="recipient"
keyOrTrustStoreParametersId="trustStoreParams" />
</marshal>
...
Spring XML Recipient
<!-- key store configuration -->
<camel:keyStoreParameters id="keyStoreParams" resource="./recipient.ks" password="password" />
<camelContext id="springXmlSecurityDataFormatTestCamelContext"
xmlns="http://camel.apache.org/schema/spring"
xmlns:cheese="http://cheese.xmlsecurity.camel.apache.org/">
<route>
<from uri="direct://encrypted"/>
<unmarshal>
<secureXML
secureTag="//cheese:cheesesites/italy"
secureTagContents="true"
xmlCipherAlgorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"
keyCipherAlgorithm="http://www.w3.org/2001/04/xmlenc#rsa-1_5"
recipientKeyAlias="recipient"
keyOrTrustStoreParametersId="keyStoreParams" />
</unmarshal>
...
DependenciesThis data format is provided in the camel-xmlsecurity component. The GZip Data Format is a message compression and de-compression format. It uses the same deflate algorithm that is used in Zip DataFormat, although some additional headers are provided. This format is produced by popular gzip/gunzip tool. Messages marshalled using GZip compression can be unmarshalled using GZip decompression just prior to being consumed at the endpoint. The compression capability is quite useful when you deal with large XML and Text based payloads or when you read messages previously comressed using gzip tool. OptionsThere are no options provided for this data format. MarshalIn this example we marshal a regular text/XML payload to a compressed payload employing gzip compression format and send it an ActiveMQ queue called MY_QUEUE. from("direct:start").marshal().gzip().to("activemq:queue:MY_QUEUE"); UnmarshalIn this example we unmarshal a gzipped payload from an ActiveMQ queue called MY_QUEUE to its original format, and forward it for processing to the UnGZippedMessageProcessor. from("activemq:queue:MY_QUEUE").unmarshal().gzip().process(new UnGZippedMessageProcessor()); DependenciesThis data format is provided in camel-core so no additional dependencies is needed. CastorAvailable as of Camel 2.1 Castor is a Data Format which uses the Castor XML library to unmarshal an XML payload into Java objects or to marshal Java objects into an XML payload. As usually you can use either Java DSL or Spring XML to work with Castor Data Format. Using the Java DSLfrom("direct:order"). marshal().castor(). to("activemq:queue:order"); For example the following uses a named DataFormat of Castor which uses default Castor data binding features. CastorDataFormat castor = new CastorDataFormat (); from("activemq:My.Queue"). unmarshal(castor). to("mqseries:Another.Queue"); If you prefer to use a named reference to a data format which can then be defined in your Registry such as via your Spring XML file. e.g. from("activemq:My.Queue"). unmarshal("mycastorType"). to("mqseries:Another.Queue"); If you want to override default mapping schema by providing a mapping file you can set it as follows. CastorDataFormat castor = new CastorDataFormat (); castor.setMappingFile("mapping.xml"); Also if you want to have more control on Castor Marshaller and Unmarshaller you can access them as below. castor.getMarshaller(); castor.getUnmarshaller(); Using Spring XMLThe following example shows how to use Castor to unmarshal using Spring configuring the castor data type <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <unmarshal> <castor validation="true" /> </unmarshal> <to uri="mock:result"/> </route> </camelContext> This example shows how to configure the data type just once and reuse it on multiple routes. You have to set the <castor> element directly in <camelContext>. <camelContext> <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <castor id="myCastor"/> </dataFormats> <route> <from uri="direct:start"/> <marshal ref="myCastor"/> <to uri="direct:marshalled"/> </route> <route> <from uri="direct:marshalled"/> <unmarshal ref="myCastor"/> <to uri="mock:result"/> </route> </camelContext> OptionsCastor supports the following options
DependenciesTo use Castor in your camel routes you need to add the a dependency on camel-castor which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-castor</artifactId> <version>2.1.0</version> </dependency> Protobuf - Protocol Buffers"Protocol Buffers - Google's data interchange format"
Camel provides a Data Format to serialse between Java and the Protocol Buffer protocol. The project's site details why you may wish to choose this format over xml. Protocol Buffer is language-neutral and platform-neutral, so messages produced by your Camel routes may be consumed by other language implementations. API Site Protobuf overviewThis quick overview of how to use Protobuf. For more detail see the complete tutorial Defining the proto formatThe first step is to define the format for the body of your exchange. This is defined in a .proto file as so: addressbook.proto package org.apache.camel.component.protobuf; option java_package = "org.apache.camel.component.protobuf"; option java_outer_classname = "AddressBookProtos"; message Person { required string name = 1; required int32 id = 2; optional string email = 3; enum PhoneType { MOBILE = 0; HOME = 1; WORK = 2; } message PhoneNumber { required string number = 1; optional PhoneType type = 2 [default = HOME]; } repeated PhoneNumber phone = 4; } message AddressBook { repeated Person person = 1; } Generating Java classesThe Protobuf SDK provides a compiler which will generate the Java classes for the format we defined in our .proto file. You can run the compiler for any additional supported languages you require. protoc --java_out=. ./addressbook.proto This will generate a single Java class named AddressBookProtos which contains inner classes for Person and AddressBook. Builders are also implemented for you. The generated classes implement com.google.protobuf.Message which is required by the serialisation mechanism. For this reason it important that only these classes are used in the body of your exchanges. Camel will throw an exception on route creation if you attempt to tell the Data Format to use a class that does not implement com.google.protobuf.Message. Use the generated builders to translate the data from any of your existing domain classes. Java DSLYou can use create the ProtobufDataFormat instance and pass it to Camel DataFormat marshal and unmarsha API like this. ProtobufDataFormat format = new ProtobufDataFormat(Person.getDefaultInstance()); from("direct:in").marshal(format); from("direct:back").unmarshal(format).to("mock:reverse"); Or use the DSL protobuf() passing the unmarshal default instance or default instance class name like this. // You don't need to specify the default instance for protobuf marshaling from("direct:marshal").marshal().protobuf(); from("direct:unmarshalA").unmarshal(). protobuf("org.apache.camel.dataformat.protobuf.generated.AddressBookProtos$Person"). to ("mock:reverse"); from("direct:unmarshalB").unmarshal().protobuf(Person.getDefaultInstance()).to("mock:reverse"); Spring DSLThe following example shows how to use Castor to unmarshal using Spring configuring the protobuf data type <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <unmarshal> <protobuf instanceClass="org.apache.camel.dataformat.protobuf.generated.AddressBookProtos$Person" /> </unmarshal> <to uri="mock:result"/> </route> </camelContext> DependenciesTo use Protobuf in your camel routes you need to add the a dependency on camel-protobuf which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-protobuf</artifactId> <version>2.2.0</version> </dependency> SOAP DataFormatAvailable as of Camel 2.3 SOAP is a Data Format which uses JAXB2 and JAX-WS annotations to marshal and unmarshal SOAP payloads. It provides the basic features of Apache CXF without need for the CXF Stack. ElementNameStrategyAn element name strategy is used for two purposes. The first is to find a xml element name for a given object and soap action when marshaling the object into a SOAP message. The second is to find an Exception class for a given soap fault name.
If you have generated the web service stub code with cxf-codegen or a similar tool then you probably will want to use the ServiceInterfaceStrategy. In the case you have no annotated service interface you should use QNameStrategy or TypeNameStrategy. Using the Java DSLThe following example uses a named DataFormat of soap which is configured with the package com.example.customerservice to initialize the JAXBContext. The second parameter is the ElementNameStrategy. The route is able to marshal normal objects as well as exceptions. (Note the below just sends a SOAP Envelope to a queue. A web service provider would actually need to be listening to the queue for a SOAP call to actually occur, in which case it would be a one way SOAP request. If you need request reply then you should look at the next example.) SoapJaxbDataFormat soap = new SoapJaxbDataFormat("com.example.customerservice", new ServiceInterfaceStrategy(CustomerService.class)); from("direct:start") .marshal(soap) .to("jms:myQueue");
Multi-part MessagesAvailable as of Camel 2.8.1 Multi-part SOAP messages are supported by the ServiceInterfaceStrategy. The ServiceInterfaceStrategy must be initialized with a service interface definition that is annotated in accordance with JAX-WS 2.2 and meets the requirements of the Document Bare style. The target method must meet the following criteria, as per the JAX-WS specification: 1) it must have at most one in or in/out non-header parameter, 2) if it has a return type other than void it must have no in/out or out non-header parameters, 3) if it it has a return type of void it must have at most one in/out or out non-header parameter. The ServiceInterfaceStrategy should be initialized with a boolean parameter that indicates whether the mapping strategy applies to the request parameters or response parameters. ServiceInterfaceStrategy strat = new ServiceInterfaceStrategy(com.example.customerservice.multipart.MultiPartCustomerService.class, true); SoapJaxbDataFormat soapDataFormat = new SoapJaxbDataFormat("com.example.customerservice.multipart", strat); Multi-part RequestThe payload parameters for a multi-part request are initiazlied using a BeanInvocation object that reflects the signature of the target operation. The camel-soap DataFormat maps the content in the BeanInvocation to fields in the SOAP header and body in accordance with the JAX-WS mapping when the marshal() processor is invoked. BeanInvocation beanInvocation = new BeanInvocation(); // Identify the target method beanInvocation.setMethod(MultiPartCustomerService.class.getMethod("getCustomersByName", GetCustomersByName.class, com.example.customerservice.multipart.Product.class)); // Populate the method arguments GetCustomersByName getCustomersByName = new GetCustomersByName(); getCustomersByName.setName("Dr. Multipart"); Product product = new Product(); product.setName("Multiuse Product"); product.setDescription("Useful for lots of things."); Object[] args = new Object[] {getCustomersByName, product}; // Add the arguments to the bean invocation beanInvocation.setArgs(args); // Set the bean invocation object as the message body exchange.getIn().setBody(beanInvocation); Multi-part ResponseA multi-part soap response may include an element in the soap body and will have one or more elements in the soap header. The camel-soap DataFormat will unmarshall the element in the soap body (if it exists) and place it onto the body of the out message in the exchange. Header elements will not be marshaled into their JAXB mapped object types. Instead, these elements are placed into the camel out message header org.apache.camel.dataformat.soap.UNMARSHALLED_HEADER_LIST. The elements will appear either as element instance values, or as JAXBElement values, depending upon the setting for the ignoreJAXBElement property. This property is inherited from camel-jaxb. You can also have the camel-soap DataFormate ignore header content all-together by setting the ignoreUnmarshalledHeaders value to true. Holder Object mappingJAX-WS specifies the use of a type-parameterized javax.xml.ws.Holder object for In/Out and Out parameters. A Holder object may be used when building the BeanInvocation, or you may use an instance of the parameterized-type directly. The camel-soap DataFormat marshals Holder values in accordance with the JAXB mapping for the class of the Holder's value. No mapping is provided for Holder objects in an unmarshalled response. ExamplesWebservice clientThe following route supports marshalling the request and unmarshalling a response or fault. String WS_URI = "cxf://http://myserver/customerservice?serviceClass=com.example.customerservice&dataFormat=MESSAGE"; SoapJaxbDataFormat soapDF = new SoapJaxbDataFormat("com.example.customerservice", new ServiceInterfaceStrategy(CustomerService.class)); from("direct:customerServiceClient") .onException(Exception.class) .handled(true) .unmarshal(soapDF) .end() .marshal(soapDF) .to(WS_URI) .unmarshal(soapDF); The below snippet creates a proxy for the service interface and makes a SOAP call to the above route. import org.apache.camel.Endpoint; import org.apache.camel.component.bean.ProxyHelper; ... Endpoint startEndpoint = context.getEndpoint("direct:customerServiceClient"); ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); // CustomerService below is the service endpoint interface, *not* the javax.xml.ws.Service subclass CustomerService proxy = ProxyHelper.createProxy(startEndpoint, classLoader, CustomerService.class); GetCustomersByNameResponse response = proxy.getCustomersByName(new GetCustomersByName()); Webservice ServerUsing the following route sets up a webservice server that listens on jms queue customerServiceQueue and processes requests using the class CustomerServiceImpl. The customerServiceImpl of course should implement the interface CustomerService. Instead of directly instantiating the server class it could be defined in a spring context as a regular bean. SoapJaxbDataFormat soapDF = new SoapJaxbDataFormat("com.example.customerservice", new ServiceInterfaceStrategy(CustomerService.class)); CustomerService serverBean = new CustomerServiceImpl(); from("jms://queue:customerServiceQueue") .onException(Exception.class) .handled(true) .marshal(soapDF) .end() .unmarshal(soapDF) .bean(serverBean) .marshal(soapDF); DependenciesTo use the SOAP dataformat in your camel routes you need to add the following dependency to your pom. <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-soap</artifactId> <version>2.3.0</version> </dependency> CryptoAvailable as of Camel 2.3 The Crypto Data Format integrates the Java Cryptographic Extension into Camel, allowing simple and flexible encryption and decryption of messages using Camel's familiar marshall and unmarshal formatting mechanism. It assumes marshalling to mean encryption to cyphertext and unmarshalling decryption back to the original plaintext. Options
Basic UsageAt its most basic all that is required to encrypt/decrypt an exchange is a shared secret key. If one or more instances of the Crypto data format are configured with this key the format can be used to encrypt the payload in one route (or part of one) and decrypted in another. For example, using the Java DSL as follows: KeyGenerator generator = KeyGenerator.getInstance("DES"); CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey()); from("direct:basic-encryption") .marshal(cryptoFormat) .to("mock:encrypted") .unmarshal(cryptoFormat) .to("mock:unencrypted"); In Spring the dataformat is configured first and then used in routes <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <crypto id="basic" algorithm="DES" keyRef="desKey" /> </dataFormats> ... <route> <from uri="direct:basic-encryption" /> <marshal ref="basic" /> <to uri="mock:encrypted" /> <unmarshal ref="basic" /> <to uri="mock:unencrypted" /> </route> </camelContext> Specifying the Encryption Algorithm.Changing the algorithm is a matter of supplying the JCE algorithm name. If you change the algorithm you will need to use a compatible key. KeyGenerator generator = KeyGenerator.getInstance("DES"); CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey()); cryptoFormat.setShouldAppendHMAC(true); cryptoFormat.setMacAlgorithm("HmacMD5"); from("direct:hmac-algorithm") .marshal(cryptoFormat) .to("mock:encrypted") .unmarshal(cryptoFormat) .to("mock:unencrypted"); Specifying an Initialization Vector.Some crypto algorhithms, particularly block algorithms, require configuration with an initial block of data known as an Initialization Vector. In the JCE this is passed as an AlgorithmParameterSpec when the Cipher is initialized. To use such a vector with the CryptoDataFormat you can configure it with a byte[] contianing the required data e.g. KeyGenerator generator = KeyGenerator.getInstance("DES"); byte[] initializationVector = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07}; CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES/CBC/PKCS5Padding", generator.generateKey()); cryptoFormat.setInitializationVector(initializationVector); from("direct:init-vector") .marshal(cryptoFormat) .to("mock:encrypted") .unmarshal(cryptoFormat) .to("mock:unencrypted"); or with spring, suppling a reference to a byte[] <crypto id="initvector" algorithm="DES/CBC/PKCS5Padding" keyRef="desKey" initVectorRef="initializationVector" />
The same vector is required in both the encryption and decryption phases. As it is not necessary to keep the IV a secret, the DataFormat allows for it to be inlined into the encrypted data and subsequently read out in the decryption phase to initialize the Cipher. To inline the IV set the /oinline flag. KeyGenerator generator = KeyGenerator.getInstance("DES"); byte[] initializationVector = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07}; SecretKey key = generator.generateKey(); CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES/CBC/PKCS5Padding", key); cryptoFormat.setInitializationVector(initializationVector); cryptoFormat.setShouldInlineInitializationVector(true); CryptoDataFormat decryptFormat = new CryptoDataFormat("DES/CBC/PKCS5Padding", key); decryptFormat.setShouldInlineInitializationVector(true); from("direct:inline") .marshal(cryptoFormat) .to("mock:encrypted") .unmarshal(decryptFormat) .to("mock:unencrypted"); or with spring. <crypto id="inline" algorithm="DES/CBC/PKCS5Padding" keyRef="desKey" initVectorRef="initializationVector" inline="true" /> <crypto id="inline-decrypt" algorithm="DES/CBC/PKCS5Padding" keyRef="desKey" inline="true" /> For more information of the use of Initialization Vectors, consult
Hashed Message Authentication Codes (HMAC)To avoid attacks against the encrypted data while it is in transit the CryptoDataFormat can also calculate a Message Authentication Code forthe encrypted exchange contents based on a configurable MAC algorithm. The calculated HMAC is appended to the stream after encryption. It is separated from the stream in the decryption phase. The MAC is recalculated and verified against the transmitted version to insure nothing was tampered with in transit.For more information on Message Authentication Codes see http://en.wikipedia.org/wiki/HMAC KeyGenerator generator = KeyGenerator.getInstance("DES"); CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey()); cryptoFormat.setShouldAppendHMAC(true); from("direct:hmac") .marshal(cryptoFormat) .to("mock:encrypted") .unmarshal(cryptoFormat) .to("mock:unencrypted"); or with spring. <crypto id="hmac" algorithm="DES" keyRef="desKey" shouldAppendHMAC="true" />
By default the HMAC is calculated using the HmacSHA1 mac algorithm though this can be easily changed by supplying a different algorithm name. See here for how to check what algorithms are available through the configured security providers KeyGenerator generator = KeyGenerator.getInstance("DES"); CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey()); cryptoFormat.setShouldAppendHMAC(true); cryptoFormat.setMacAlgorithm("HmacMD5"); from("direct:hmac-algorithm") .marshal(cryptoFormat) .to("mock:encrypted") .unmarshal(cryptoFormat) .to("mock:unencrypted"); or with spring. <crypto id="hmac-algorithm" algorithm="DES" keyRef="desKey" macAlgorithm="HmacMD5" shouldAppendHMAC="true" />
Supplying Keys dynamically.When using a Recipient list or similar EIP the recipient of an exchange can vary dynamically. Using the same key across all recipients may neither be feasible or desirable. It would be useful to be able to specify keys dynamically on a per exchange basis. The exchange could then be dynamically enriched with the key of its target recipient before being processed by the data format. To facilitate this the DataFormat allow for keys to be supplied dynamically via the message headers below
CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", null); /** * Note: the header containing the key should be cleared after * marshalling to stop it from leaking by accident and * potentially being compromised. The processor version below is * arguably better as the key is left in the header when you use * the DSL leaks the fact that camel encryption was used. */ from("direct:key-in-header-encrypt") .marshal(cryptoFormat) .removeHeader(CryptoDataFormat.KEY) .to("mock:encrypted"); from("direct:key-in-header-decrypt").unmarshal(cryptoFormat).process(new Processor() { public void process(Exchange exchange) throws Exception { exchange.getIn().getHeaders().remove(CryptoDataFormat.KEY); exchange.getOut().copyFrom(exchange.getIn()); } }).to("mock:unencrypted"); or with spring. <crypto id="nokey" algorithm="DES" />
PGPDataFormat Options
Encrypting with PGPDataFormatThe following sample uses the popular PGP format for encrypting/decypting files using the libraries from http://www.bouncycastle.org/java.html. For help managing your keyring see the next section // Public Key FileName String keyFileName = "org/apache/camel/component/crypto/pubring.gpg"; // Private Key FileName String keyFileNameSec = "org/apache/camel/component/crypto/secring.gpg"; // Keyring Userid Used to Encrypt String keyUserid = "sdude@nowhere.net"; // Private key password String keyPassword = "sdude"; from("direct:inline") .marshal().pgp(keyFileName, keyUserid) .to("mock:encrypted") .unmarshal().pgp(keyFileNameSec, keyUserid, keyPassword) .to("mock:unencrypted"); or using spring <dataFormats> <!-- will load the file from classpath by default, but you can prefix with file: to load from file system --> <pgp id="encrypt" keyFileName="org/apache/camel/component/crypto/pubring.gpg" keyUserid="sdude@nowhere.net"/> <pgp id="decrypt" keyFileName="org/apache/camel/component/crypto/secring.gpg" keyUserid="sdude@nowhere.net" password="sdude"/> </dataFormats> <route> <from uri="direct:inline"/> <marshal ref="encrypt"/> <to uri="mock:encrypted"/> <unmarshal ref="decrypt"/> <to uri="mock:unencrypted"/> </route> To work with the previous example you need the following
Managing your keyringTo manage the keyring, I use the command line tools, I find this to be the simplest approach in managing the keys. There are also Java libraries available from http://www.bouncycastle.org/java.html if you would prefer to do it that way.
DependenciesTo use the Crypto dataformat in your camel routes you need to add the following dependency to your pom. <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-crypto</artifactId> <version>2.9.0</version> </dependency> See AlsoSyslog DataFormatAvailable as of Camel 2.6 The syslog dataformat is used for working with RFC3164 messages. This component supports the following:
Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-syslog</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> RFC3164 Syslog protocolSyslog uses the user datagram protocol (UDP) 1 as its underlying transport layer mechanism. To expose a Syslog listener service we reuse the existing camel-mina component or camel-netty where we just use the Rfc3164SyslogDataFormat to marshal and unmarshal messages Exposing a Syslog listenerIn our Spring XML file, we configure an endpoint to listen for udp messages on port 10514, note that in netty we disable the defaultCodec, this <camelContext id="myCamel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <syslog id="mySyslog"/> </dataFormats> <route> <from uri="netty:udp://localhost:10514?sync=false&allowDefaultCodec=false"/> <unmarshal ref="mySyslog"/> <to uri="mock:stop1"/> </route> </camelContext> The same route using camel-mina <camelContext id="myCamel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <syslog id="mySyslog"/> </dataFormats> <route> <from uri="mina:udp://localhost:10514"/> <unmarshal ref="mySyslog"/> <to uri="mock:stop1"/> </route> </camelContext> Sending syslog messages to a remote destination<camelContext id="myCamel" xmlns="http://camel.apache.org/schema/spring"> <dataFormats> <syslog id="mySyslog"/> </dataFormats> <route> <from uri="direct:syslogMessages"/> <marshal ref="mySyslog"/> <to uri="mina:udp://remotehost:10514"/> </route> </camelContext> See AlsoPattern AppendixThere now follows a breakdown of the various Enterprise Integration Patterns that Camel supports Messaging SystemsMessage ChannelCamel supports the Message Channel from the EIP patterns. The Message Channel is an internal implementation detail of the Endpoint interface and all interactions with the Message Channel are via the Endpoint interfaces.
For more details see Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. MessageCamel supports the Message from the EIP patterns using the Message interface.
To support various message exchange patterns like one way Event Message and Request Reply messages Camel uses an Exchange interface which has a pattern property which can be set to InOnly for an Event Message which has a single inbound Message, or InOut for a Request Reply where there is an inbound and outbound message. Here is a basic example of sending a Message to a route in InOnly and InOut modes Requestor Code //InOnly getContext().createProducerTemplate().sendBody("direct:startInOnly", "Hello World"); //InOut String result = (String) getContext().createProducerTemplate().requestBody("direct:startInOut", "Hello World"); Route Using the Fluent Builders from("direct:startInOnly").inOnly("bean:process"); from("direct:startInOut").inOut("bean:process"); Route Using the Spring XML Extensions <route> <from uri="direct:startInOnly"/> <inOnly uri="bean:process"/> </route> <route> <from uri="direct:startInOut"/> <inOut uri="bean:process"/> </route> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Pipes and FiltersCamel supports the Pipes and Filters from the EIP patterns in various ways.
With Camel you can split your processing across multiple independent Endpoint instances which can then be chained together. Using Routing LogicYou can create pipelines of logic using multiple Endpoint or Message Translator instances as follows from("direct:a").pipeline("direct:x", "direct:y", "direct:z", "mock:result"); Though pipeline is the default mode of operation when you specify multiple outputs in Camel. The opposite to pipeline is multicast; which fires the same message into each of its outputs. (See the example below). In Spring XML you can use the <pipeline/> element as of 1.4.0 onwards <route> <from uri="activemq:SomeQueue"/> <pipeline> <bean ref="foo"/> <bean ref="bar"/> <to uri="activemq:OutputQueue"/> </pipeline> </route> In the above the pipeline element is actually unnecessary, you could use this... <route> <from uri="activemq:SomeQueue"/> <bean ref="foo"/> <bean ref="bar"/> <to uri="activemq:OutputQueue"/> </route> Its just a bit more explicit. However if you wish to use <multicast/> to avoid a pipeline - to send the same message into multiple pipelines - then the <pipeline/> element comes into its own. <route> <from uri="activemq:SomeQueue"/> <multicast> <pipeline> <bean ref="something"/> <to uri="log:Something"/> </pipeline> <pipeline> <bean ref="foo"/> <bean ref="bar"/> <to uri="activemq:OutputQueue"/> </pipeline> </multicast> </route> In the above example we are routing from a single Endpoint to a list of different endpoints specified using URIs. If you find the above a bit confusing, try reading about the Architecture or try the Examples Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message RouterThe Message Router from the EIP patterns allows you to consume from an input destination, evaluate some predicate then choose the right output destination.
The following example shows how to route a request from an input queue:a endpoint to either queue:b, queue:c or queue:d depending on the evaluation of various Predicate expressions Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .choice() .when(header("foo").isEqualTo("bar")) .to("seda:b") .when(header("foo").isEqualTo("cheese")) .to("seda:c") .otherwise() .to("seda:d"); } }; Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <choice> <when> <xpath>$foo = 'bar'</xpath> <to uri="seda:b"/> </when> <when> <xpath>$foo = 'cheese'</xpath> <to uri="seda:c"/> </when> <otherwise> <to uri="seda:d"/> </otherwise> </choice> </route> </camelContext> Choice without otherwiseIf you use a choice without adding an otherwise, any unmatched exchanges will be dropped by default. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message TranslatorCamel supports the Message Translator from the EIP patterns by using an arbitrary Processor in the routing logic, by using a bean to perform the transformation, or by using transform() in the DSL. You can also use a Data Format to marshal and unmarshal messages in different encodings.
Using the Fluent Builders You can transform a message using Camel's Bean Integration to call any method on a bean in your Registry such as your Spring XML configuration file as follows from("activemq:SomeQueue"). beanRef("myTransformerBean", "myMethodName"). to("mqseries:AnotherQueue"); Where the "myTransformerBean" would be defined in a Spring XML file or defined in JNDI etc. You can omit the method name parameter from beanRef() and the Bean Integration will try to deduce the method to invoke from the message exchange. or you can add your own explicit Processor to do the transformation from("direct:start").process(new Processor() { public void process(Exchange exchange) { Message in = exchange.getIn(); in.setBody(in.getBody(String.class) + " World!"); } }).to("mock:result"); or you can use the DSL to explicitly configure the transformation from("direct:start").transform(body().append(" World!")).to("mock:result"); Use Spring XML You can also use Spring XML Extensions to do a transformation. Basically any Expression language can be substituted inside the transform element as shown below <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <transform> <simple>${in.body} extra data!</simple> </transform> <to uri="mock:end"/> </route> </camelContext> Or you can use the Bean Integration to invoke a bean <route> <from uri="activemq:Input"/> <bean ref="myBeanName" method="doTransform"/> <to uri="activemq:Output"/> </route> You can also use Templating to consume a message from one destination, transform it with something like Velocity or XQuery and then send it on to another destination. For example using InOnly (one way messaging) from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"). to("activemq:Another.Queue"); If you want to use InOut (request-reply) semantics to process requests on the My.Queue queue on ActiveMQ with a template generated response, then sending responses back to the JMSReplyTo Destination you could use this. from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"); Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message EndpointCamel supports the Message Endpoint from the EIP patterns using the Endpoint interface.
When using the DSL to create Routes you typically refer to Message Endpoints by their URIs rather than directly using the Endpoint interface. Its then a responsibility of the CamelContext to create and activate the necessary Endpoint instances using the available Component implementations. For more details see Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Messaging ChannelsPoint to Point ChannelCamel supports the Point to Point Channel from the EIP patterns using the following components
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Publish Subscribe ChannelCamel supports the Publish Subscribe Channel from the EIP patterns using for example the following components:
Using Routing LogicAnother option is to explicitly list the publish-subscribe relationship in your routing logic; this keeps the producer and consumer decoupled but lets you control the fine grained routing configuration using the DSL or Xml Configuration. Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .multicast().to("seda:b", "seda:c", "seda:d"); } }; Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <multicast> <to uri="seda:b"/> <to uri="seda:c"/> <to uri="seda:d"/> </multicast> </route> </camelContext> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Dead Letter ChannelCamel supports the Dead Letter Channel from the EIP patterns using the DeadLetterChannel processor which is an Error Handler.
RedeliveryIt is common for a temporary outage or database deadlock to cause a message to fail to process; but the chances are if its tried a few more times with some time delay then it will complete fine. So we typically wish to use some kind of redelivery policy to decide how many times to try redeliver a message and how long to wait before redelivery attempts. The RedeliveryPolicy defines how the message is to be redelivered. You can customize things like
Once all attempts at redelivering the message fails then the message is forwarded to the dead letter queue. About moving Exchange to dead letter queue and using handledHandled on Dead Letter Channel was introduced in Camel 2.0, this feature does not exist in Camel 1.x When all attempts of redelivery have failed the Exchange is moved to the dead letter queue (the dead letter endpoint). The exchange is then complete and from the client point of view it was processed. As such the Dead Letter Channel have handled the Exchange. For instance configuring the dead letter channel as: Using the Fluent Builders
errorHandler(deadLetterChannel("jms:queue:dead")
.maximumRedeliveries(3).redeliveryDelay(5000));
Using the Spring XML Extensions <route errorHandlerRef="myDeadLetterErrorHandler"> ... </route> <bean id="myDeadLetterErrorHandler" class="org.apache.camel.builder.DeadLetterChannelBuilder"> <property name="deadLetterUri" value="jms:queue:dead"/> <property name="redeliveryPolicy" ref="myRedeliveryPolicyConfig"/> </bean> <bean id="myRedeliveryPolicyConfig" class="org.apache.camel.processor.RedeliveryPolicy"> <property name="maximumRedeliveries" value="3"/> <property name="redeliveryDelay" value="5000"/> </bean> The Dead Letter Channel above will clear the caused exception (setException(null)), by moving the caused exception to a property on the Exchange, with the key Exchange.EXCEPTION_CAUGHT. Then the Exchange is moved to the "jms:queue:dead" destination and the client will not notice the failure. About moving Exchange to dead letter queue and using the original messageAvailable as of Camel 2.0 For instance if you have this route: from("jms:queue:order:input") .to("bean:validateOrder") .to("bean:transformOrder") .to("bean:handleOrder"); The route listen for JMS messages and validates, transforms and handle it. During this the Exchange payload is transformed/modified. So in case something goes wrong and we want to move the message to another JMS destination, then we can configure our Dead Letter Channel with the useOriginalBody option. But when we move the Exchange to this destination we do not know in which state the message is in. Did the error happen in before the transformOrder or after? So to be sure we want to move the original input message we received from jms:queue:order:input. So we can do this by enabling the useOriginalMessage option as shown below:
// will use original body
errorHandler(deadLetterChannel("jms:queue:dead")
.useOriginalMessage().mamimumRedeliveries(5).redeliverDelay(5000);
Then the messages routed to the jms:queue:dead is the original input. If we want to manually retry we can move the JMS message from the failed to the input queue, with no problem as the message is the same as the original we received. OnRedeliveryAvailable in Camel 1.6.0 onwards When Dead Letter Channel is doing redeliver its possible to configure a Processor that is executed just before every redelivery attempt. This can be used for the situations where you need to alter the message before its redelivered. See below for sample.
Redelivery default valuesIn Camel 2.0 redelivery is disabled by default, as opposed to Camel 1.x in which Dead Letter Channel is configured with maximumRedeliveries=5. The default redeliver policy will use the following values:
The maximum redeliver delay ensures that a delay is never longer than the value, default 1 minute. This can happen if you turn on the exponential backoff. The maximum redeliveries is the number of re delivery attempts. By default Camel will try to process the exchange 1 + 5 times. 1 time for the normal attempt and then 5 attempts as redeliveries. Camel will log delivery failures at the DEBUG logging level by default. You can change this by specifying retriesExhaustedLogLevel and/or retryAttemptedLogLevel. See ExceptionBuilderWithRetryLoggingLevelSetTest for an example. In Camel 2.0 you can turn logging of stack traces on/off. If turned off Camel will still log the redelivery attempt. Its just much less verbose. Redeliver Delay PatternAvailable as of Camel 2.0 The idea is to set groups of ranges using the following syntax: limit:delay;limit 2:delay 2;limit 3:delay 3;...;limit N:delay N Each group has two values separated with colon
Lets clarify this with an example: That gives us 3 groups:
Resulting in these delays for redelivery attempt:
Note: The first redelivery attempt is 1, so the first group should start with 1 or higher. You can start a group with limit 1 to eg have a starting delay: delayPattern=1:1000;5:5000
There is no requirement that the next delay should be higher than the previous. You can use any delay value you like. For example with delayPattern=1:5000;3:1000 we start with 5 sec delay and then later reduce that to 1 second. Redelivery headerWhen a message is redelivered the DeadLetterChannel will append a customizable header to the message to indicate how many times its been redelivered. And a boolean flag whether it is being redelivered or not (first attempt) Dynamically calculated delay from the exchange Which endpoint failedAvailable as of Camel 2.1 When Camel routes messages it will decorate the Exchange with a property that contains the last endpoint Camel send the Exchange to: String lastEndpointUri = exchange.getProperty(Exchange.TO_ENDPOINT, String.class); The Exchange.TO_ENDPOINT have the constant value CamelToEndpoint. This information is updated when Camel sends a message to any endpoint. So if it exists its the last endpoint which Camel send the Exchange to. When for example processing the Exchange at a given Endpoint and the message is to be moved into the dead letter queue, then Camel also decorates the Exchange with another property that contains that last endpoint: String failedEndpointUri = exchange.getProperty(Exchange.FAILURE_ENDPOINT, String.class); The Exchange.FAILURE_ENDPOINT have the constant value CamelFailureEndpoint. This allows for example you to fetch this information in your dead letter queue and use that for error reporting. Notice: These information is kept on the Exchange even if the message was successfully processed by a given endpoint, and then later fails for example in a local Bean processing instead. So beware that this is a hint that helps pinpoint errors. from("activemq:queue:foo") .to("http://someserver/somepath") .beanRef("foo"); Now suppose the route above and a failure happens in the foo bean. Then the Exchange.TO_ENDPOINT and Exchange.FAILURE_ENDPOINT will still contain the value of http://someserver/somepath. SamplesThe following example shows how to configure the Dead Letter Channel configuration using the DSL RouteBuilder builder = new RouteBuilder() { public void configure() { // using dead letter channel with a seda queue for errors errorHandler(deadLetterChannel("seda:errors")); // here is our route from("seda:a").to("seda:b"); } }; You can also configure the RedeliveryPolicy as this example shows RouteBuilder builder = new RouteBuilder() { public void configure() { // configures dead letter channel to use seda queue for errors and use at most 2 redelveries // and exponential backoff errorHandler(deadLetterChannel("seda:errors").maximumRedeliveries(2).useExponentialBackOff()); // here is our route from("seda:a").to("seda:b"); } }; How can I modify the Exchange before redelivery?In Camel 1.6.0 we added support directly in Dead Letter Channel to set a Processor that is executed before each redelivery attempt. When Dead Letter Channel is doing redeliver its possible to configure a Processor that is executed just before every redelivery attempt. This can be used for the situations where you need to alter the message before its redelivered. Here we configure the Dead Letter Channel to use our processor MyRedeliveryProcessor to be executed before each redelivery. // we configure our Dead Letter Channel to invoke // MyRedeliveryProcessor before a redelivery is // attempted. This allows us to alter the message before errorHandler(deadLetterChannel("mock:error").maximumRedeliveries(5) .onRedelivery(new MyRedeliverProcessor()) // setting delay to zero is just to make unit testing faster .redeliveryDelay(0L)); And this is the processor MyRedeliveryProcessor where we alter the message. // This is our processor that is executed before every redelivery attempt // here we can do what we want in the java code, such as altering the message public class MyRedeliverProcessor implements Processor { public void process(Exchange exchange) throws Exception { // the message is being redelivered so we can alter it // we just append the redelivery counter to the body // you can of course do all kind of stuff instead String body = exchange.getIn().getBody(String.class); int count = exchange.getIn().getHeader(Exchange.REDELIVERY_COUNTER, Integer.class); exchange.getIn().setBody(body + count); // the maximum redelivery was set to 5 int max = exchange.getIn().getHeader(Exchange.REDELIVERY_MAX_COUNTER, Integer.class); assertEquals(5, max); } } Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Guaranteed DeliveryCamel supports the Guaranteed Delivery from the EIP patterns using among others the following components:
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message BusCamel supports the Message Bus from the EIP patterns. You could view Camel as a Message Bus itself as it allows producers and consumers to be decoupled.
Folks often assume that a Message Bus is a JMS though so you may wish to refer to the JMS component for traditional MOM support. Of course there are also ESB products such as Apache ServiceMix which serve as full fledged message busses. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message ConstructionEvent MessageCamel supports the Event Message from the EIP patterns by supporting the Exchange Pattern on a Message which can be set to InOnly to indicate a oneway event message. Camel Components then implement this pattern using the underlying transport or protocols.
The default behaviour of many Components is InOnly such as for JMS, File or SEDA
Explicitly specifying InOnlyIf you are using a component which defaults to InOut you can override the Exchange Pattern for an endpoint using the pattern property. foo:bar?exchangePattern=InOnly From 2.0 onwards on Camel you can specify the Exchange Pattern using the dsl. Using the Fluent Builders
from("mq:someQueue").
inOnly().
bean(Foo.class);
or you can invoke an endpoint with an explicit pattern from("mq:someQueue"). inOnly("mq:anotherQueue"); Using the Spring XML Extensions
<route>
<from uri="mq:someQueue"/>
<inOnly uri="bean:foo"/>
</route>
<route>
<from uri="mq:someQueue"/>
<inOnly uri="mq:anotherQueue"/>
</route>
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Request ReplyCamel supports the Request Reply from the EIP patterns by supporting the Exchange Pattern on a Message which can be set to InOut to indicate a request/reply. Camel Components then implement this pattern using the underlying transport or protocols.
For example when using JMS with InOut the component will by default perform these actions
Explicitly specifying InOutWhen consuming messages from JMS a Request-Reply is indicated by the presence of the JMSReplyTo header. You can explicitly force an endpoint to be in Request Reply mode by setting the exchange pattern on the URI. e.g. jms:MyQueue?exchangePattern=InOut You can specify the exchange pattern in DSL rule or Spring configuration. // Send to an endpoint using InOut from("direct:testInOut").inOut("mock:result"); // Send to an endpoint using InOut from("direct:testInOnly").inOnly("mock:result"); // Set the exchange pattern to InOut, then send it from direct:inOnly to mock:result endpoint from("direct:testSetToInOnlyThenTo") .setExchangePattern(ExchangePattern.InOnly) .to("mock:result"); from("direct:testSetToInOutThenTo") .setExchangePattern(ExchangePattern.InOut) .to("mock:result"); // Or we can pass the pattern as a parameter to the to() method from("direct:testToWithInOnlyParam").to(ExchangePattern.InOnly, "mock:result"); from("direct:testToWithInOutParam").to(ExchangePattern.InOut, "mock:result"); from("direct:testToWithRobustInOnlyParam").to(ExchangePattern.RobustInOnly, "mock:result"); // Set the exchange pattern to InOut, then send it on from("direct:testSetExchangePatternInOnly") .setExchangePattern(ExchangePattern.InOnly).to("mock:result"); <camelContext xmlns="http://camel.apache.org/schema/spring"> <!-- Send the exchange as InOnly --> <route> <from uri="direct:testInOut"/> <inOut uri="mock:result"/> </route> <!-- Send the exchange as InOnly --> <route> <from uri="direct:testInOnly"/> <inOnly uri="mock:result"/> </route> <!-- lets set the exchange pattern then send it on --> <route> <from uri="direct:testSetToInOnlyThenTo"/> <setExchangePattern pattern="InOnly"/> <to uri="mock:result"/> </route> <route> <from uri="direct:testSetToInOutThenTo"/> <setExchangePattern pattern="InOut"/> <to uri="mock:result"/> </route> <route> <from uri="direct:testSetExchangePatternInOnly"/> <setExchangePattern pattern="InOnly"/> <to uri="mock:result"/> </route> <!-- Lets pass the pattern as an argument in the to element --> <route> <from uri="direct:testToWithInOnlyParam"/> <to uri="mock:result" pattern="InOnly"/> </route> <route> <from uri="direct:testToWithInOutParam"/> <to uri="mock:result" pattern="InOut"/> </route> <route> <from uri="direct:testToWithRobustInOnlyParam"/> <to uri="mock:result" pattern="RobustInOnly"/> </route> </camelContext> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Correlation IdentifierCamel supports the Correlation Identifier from the EIP patterns by getting or setting a header on a Message. When working with the ActiveMQ or JMS components the correlation identifier header is called JMSCorrelationID. You can add your own correlation identifier to any message exchange to help correlate messages together to a single conversation (or business process).
The use of a Correlation Identifier is key to working with the Camel Business Activity Monitoring Framework and can also be highly useful when testing with simulation or canned data such as with the Mock testing framework Some EIP patterns will spin off a sub message, and in those cases, Camel will add a correlation id on the Exchange as a property with they key Exchange.CORRELATION_ID, which links back to the source Exchange. For example the Splitter, Multicast, Recipient List, and Wire Tap EIP does this. See AlsoReturn AddressCamel supports the Return Address from the EIP patterns by using the JMSReplyTo header.
For example when using JMS with InOut the component will by default return to the address given in JMSReplyTo. Requestor Code getMockEndpoint("mock:bar").expectedBodiesReceived("Bye World"); template.sendBodyAndHeader("direct:start", "World", "JMSReplyTo", "queue:bar"); Route Using the Fluent Builders from("direct:start").to("activemq:queue:foo?preserveMessageQos=true"); from("activemq:queue:foo").transform(body().prepend("Bye ")); from("activemq:queue:bar?disableReplyTo=true").to("mock:bar"); Route Using the Spring XML Extensions <route> <from uri="direct:start"/> <to uri="activemq:queue:foo?preserveMessageQos=true"/> </route> <route> <from uri="activemq:queue:foo"/> <transform> <simple>Bye ${in.body}</simple> </transform> </route> <route> <from uri="activemq:queue:bar?disableReplyTo=true"/> <to uri="mock:bar"/> </route> For a complete example of this pattern, see this junit test case Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message RoutingContent Based RouterThe Content Based Router from the EIP patterns allows you to route messages to the correct destination based on the contents of the message exchanges.
The following example shows how to route a request from an input seda:a endpoint to either seda:b, seda:c or seda:d depending on the evaluation of various Predicate expressions Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .choice() .when(header("foo").isEqualTo("bar")) .to("seda:b") .when(header("foo").isEqualTo("cheese")) .to("seda:c") .otherwise() .to("seda:d"); } }; Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <choice> <when> <xpath>$foo = 'bar'</xpath> <to uri="seda:b"/> </when> <when> <xpath>$foo = 'cheese'</xpath> <to uri="seda:c"/> </when> <otherwise> <to uri="seda:d"/> </otherwise> </choice> </route> </camelContext> For further examples of this pattern in use you could look at the junit test case Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message FilterThe Message Filter from the EIP patterns allows you to filter messages
The following example shows how to create a Message Filter route consuming messages from an endpoint called queue:a which if the Predicate is true will be dispatched to queue:b Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .filter(header("foo").isEqualTo("bar")) .to("seda:b"); } }; You can of course use many different Predicate languages such as XPath, XQuery, SQL or various Scripting Languages. Here is an XPath example from("direct:start"). filter().xpath("/person[@name='James']"). to("mock:result"); Here is another example of using a bean to define the filter behavior from("direct:start") .filter().method(MyBean.class, "isGoldCustomer").to("mock:result").end() .to("mock:end"); public static class MyBean { public boolean isGoldCustomer(@Header("level") String level) { return level.equals("gold"); } } Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <filter> <xpath>$foo = 'bar'</xpath> <to uri="seda:b"/> </filter> </route> </camelContext>
For further examples of this pattern in use you could look at the junit test case Using stopAvailable as of Camel 2.0 Stop is a bit different than a message filter as it will filter out all messages and end the route entirely (filter only applies to its child processor). Stop is convenient to use in a Content Based Router when you for example need to stop further processing in one of the predicates. In the example below we do not want to route messages any further that has the word Bye in the message body. Notice how we prevent this in the when predicate by using the .stop(). from("direct:start") .choice() .when(body().contains("Hello")).to("mock:hello") .when(body().contains("Bye")).to("mock:bye").stop() .otherwise().to("mock:other") .end() .to("mock:result"); Knowing if Exchange was filtered or notAvailable as of Camel 2.5 The Message Filter EIP will add a property on the Exchange which states if it was filtered or not. The property has the key Exchannge.FILTER_MATCHED which has the String value of CamelFilterMatched. Its value is a boolean indicating true or false. If the value is true then the Exchange was routed in the filter block. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Dynamic RouterThe Dynamic Router from the EIP patterns allows you to route messages while avoiding the dependency of the router on all possible destinations while maintaining its efficiency.
In Camel 2.5 we introduced a dynamicRouter in the DSL which is like a dynamic Routing Slip which evaluates the slip on-the-fly.
Options
Dynamic Router in Camel 2.5 onwardsFrom Camel 2.5 the Dynamic Router will set a property (Exchange.SLIP_ENDPOINT) on the Exchange which contains the current endpoint as it advanced though the slip. This allows you to know how far we have processed in the slip. (It's a slip because the Dynamic Router implementation is based on top of Routing Slip). Java DSLIn Java DSL you can use the dynamicRouter as shown below: from("direct:start") // use a bean as the dynamic router .dynamicRouter(bean(DynamicRouterTest.class, "slip")); Which will leverage a Bean to compute the slip on-the-fly, which could be implemented as follows: /** * Use this method to compute dynamic where we should route next. * * @param body the message body * @return endpoints to go, or <tt>null</tt> to indicate the end */ public String slip(String body) { bodies.add(body); invoked++; if (invoked == 1) { return "mock:a"; } else if (invoked == 2) { return "mock:b,mock:c"; } else if (invoked == 3) { return "direct:foo"; } else if (invoked == 4) { return "mock:result"; } // no more so return null return null; } Mind that this example is only for show and tell. The current implementation is not thread safe. You would have to store the state on the Exchange, to ensure thread safety. Spring XMLThe same example in Spring XML would be: <bean id="mySlip" class="org.apache.camel.processor.DynamicRouterTest"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <dynamicRouter> <!-- use a method call on a bean as dynamic router --> <method ref="mySlip" method="slip"/> </dynamicRouter> </route> <route> <from uri="direct:foo"/> <transform><constant>Bye World</constant></transform> <to uri="mock:foo"/> </route> </camelContext> @DynamicRouter annotationYou can also use the @DynamicRouter annotation, for example the Camel 2.4 example below could be written as follows. The route method would then be invoked repeatedly as the message is processed dynamically. The idea is to return the next endpoint uri where to go. Return null to indicate the end. You can return multiple endpoints if you like, just as the Routing Slip, where each endpoint is separated by a delimiter. public class MyDynamicRouter { @Consume(uri = "activemq:foo") @DynamicRouter public String route(@XPath("/customer/id") String customerId, @Header("Location") String location, Document body) { // query a database to find the best match of the endpoint based on the input parameteres // return the next endpoint uri, where to go. Return null to indicate the end. } } Dynamic Router in Camel 2.4 or olderThe simplest way to implement this is to use the RecipientList Annotation on a Bean method to determine where to route the message. public class MyDynamicRouter { @Consume(uri = "activemq:foo") @RecipientList public List<String> route(@XPath("/customer/id") String customerId, @Header("Location") String location, Document body) { // query a database to find the best match of the endpoint based on the input parameteres ... } } In the above we can use the Parameter Binding Annotations to bind different parts of the Message to method parameters or use an Expression such as using XPath or XQuery. The method can be invoked in a number of ways as described in the Bean Integration such as
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Recipient ListThe Recipient List from the EIP patterns allows you to route messages to a number of dynamically specified recipients.
The recipients will receive a copy of the same Exchange and Camel will execute them sequentially. Options
Static Recipient ListThe following example shows how to route a request from an input queue:a endpoint to a static list of destinations Using Annotations Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .multicast().to("seda:b", "seda:c", "seda:d"); } }; Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <multicast> <to uri="seda:b"/> <to uri="seda:c"/> <to uri="seda:d"/> </multicast> </route> </camelContext> Dynamic Recipient ListUsually one of the main reasons for using the Recipient List pattern is that the list of recipients is dynamic and calculated at runtime. The following example demonstrates how to create a dynamic recipient list using an Expression (which in this case it extracts a named header value dynamically) to calculate the list of endpoints which are either of type Endpoint or are converted to a String and then resolved using the endpoint URIs. Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .recipientList(header("foo")); } }; The above assumes that the header contains a list of endpoint URIs. The following takes a single string header and tokenizes it from("direct:a").recipientList( header("recipientListHeader").tokenize(",")); Iteratable valueThe dynamic list of recipients that are defined in the header must be iteratable such as:
Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <recipientList> <xpath>$foo</xpath> </recipientList> </route> </camelContext> For further examples of this pattern in use you could look at one of the junit test case Using delimiter in Spring XMLAvailable as of Camel 1.6.0 <route> <from uri="direct:a" /> <!-- use comma as a delimiter for String based values --> <recipientList delimiter=","> <header>myHeader</header> </recipientList> </route> So if myHeader contains a String with the value "activemq:queue:foo, activemq:topic:hello , log:bar" then Camel will split the String using the delimiter given in the XML that was comma, resulting into 3 endpoints to send to. You can use spaces between the endpoints as Camel will trim the value when it lookup the endpoint to send to. Note: In Java DSL you use the tokenizer to archive the same. The route above in Java DSL:
from("direct:a").recipientList(header("myHeader").tokenize(","));
In Camel 2.1 its a bit easier as you can pass in the delimiter as 2nd parameter:
from("direct:a").recipientList(header("myHeader"), "#");
Sending to multiple recipients in parallelAvailable as of Camel 2.2 The Recipient List now supports parallelProcessing that for example Splitter also supports. You can use it to use a thread pool to have concurrent tasks sending the Exchange to multiple recipients concurrently.
from("direct:a").recipientList(header("myHeader")).parallelProcessing();
And in Spring XML its an attribute on the recipient list tag.
<route>
<from uri="direct:a"/>
<recipientList parallelProcessing="true">
<header>myHeader</header>
</recipientList>
</route>
Stop continuing in case one recipient failedAvailable as of Camel 2.2 The Recipient List now supports stopOnException that for example Splitter also supports. You can use it to stop sending to any further recipients in case any recipient failed.
from("direct:a").recipientList(header("myHeader")).stopOnException();
And in Spring XML its an attribute on the recipient list tag.
<route>
<from uri="direct:a"/>
<recipientList stopOnException="true">
<header>myHeader</header>
</recipientList>
</route>
Note: You can combine parallelProcessing and stopOnException and have them both true. Ignore invalid endpointsAvailable as of Camel 2.3 The Recipient List now supports ignoreInvalidEndpoints which the Routing Slip also supports. You can use it to skip endpoints which is invalid.
from("direct:a").recipientList(header("myHeader")).ignoreInvalidEndpoints();
And in Spring XML its an attribute on the recipient list tag.
<route>
<from uri="direct:a"/>
<recipientList ignoreInvalidEndpoints="true">
<header>myHeader</header>
</recipientList>
</route>
Then lets say the myHeader contains the following two endpoints direct:foo,xxx:bar. The first endpoint is valid and works. However the 2nd is invalid and will just be ignored. Camel logs at INFO level about, so you can see why the endpoint was invalid. Using custom AggregationStrategyAvailable as of Camel 2.2 You can now use you own AggregationStrategy with the Recipient List. However its not that often you need that. What its good for is that in case you are using Request Reply messaging then the replies from the recipient can be aggregated. By default Camel uses UseLatestAggregationStrategy which just keeps that last received reply. What if you must remember all the bodies that all the recipients send back, then you can use your own custom aggregator that keeps those. Its the same principle as with the Aggregator EIP so check it out for details.
from("direct:a")
.recipientList(header("myHeader")).aggregationStrategy(new MyOwnAggregationStrategy())
.to("direct:b");
And in Spring XML its an attribute on the recipient list tag.
<route>
<from uri="direct:a"/>
<recipientList strategyRef="myStrategy">
<header>myHeader</header>
</recipientList>
<to uri="direct:b"/>
</route>
<bean id="myStrategy" class="com.mycompany.MyOwnAggregationStrategy"/>
Using custom thread poolAvailable as of Camel 2.2 A thread pool is only used for parallelProcessing. You supply your own custom thread pool via the ExecutorServiceStrategy (see Camel's Threading Model), the same way you would do it for the aggregationStrategy. By default Camel uses a thread pool with 10 threads (subject to change in a future version). Using method call as recipient listYou can use a Bean to provide the recipients, for example: from("activemq:queue:test").recipientList().method(MessageRouter.class, "routeTo"); And then MessageRouter: public class MessageRouter { public String routeTo() { String queueName = "activemq:queue:test2"; return queueName; } } When you use a Bean then do not also use the @RecipientList annotation as this will in fact add yet another recipient list, so you end up having two. Do not do like this. public class MessageRouter { @RecipientList public String routeTo() { String queueName = "activemq:queue:test2"; return queueName; } } Well you should only do like that above (using @RecipientList) if you route just route to a Bean which you then want to act as a recipient list. from("activemq:queue:test").bean(MessageRouter.class, "routeTo"); Which then would invoke the routeTo method and detect its annotated with @RecipientList and then act accordingly as if it was a recipient list EIP. Using timeoutAvailable as of Camel 2.5 If you use parallelProcessing then you can configure a total timeout value in millis. Camel will then process the messages in parallel until the timeout is hit. This allows you to continue processing if one message is slow. For example you can set a timeout value of 20 sec. For example in the unit test below you can see we multicast the message to 3 destinations. We have a timeout of 2 seconds, which means only the last two messages can be completed within the timeframe. This means we will only aggregate the last two which yields a result aggregation which outputs "BC". from("direct:start") .multicast(new AggregationStrategy() { public Exchange aggregate(Exchange oldExchange, Exchange newExchange) { if (oldExchange == null) { return newExchange; } String body = oldExchange.getIn().getBody(String.class); oldExchange.getIn().setBody(body + newExchange.getIn().getBody(String.class)); return oldExchange; } }) .parallelProcessing().timeout(250).to("direct:a", "direct:b", "direct:c") // use end to indicate end of multicast route .end() .to("mock:result"); from("direct:a").delay(1000).to("mock:A").setBody(constant("A")); from("direct:b").to("mock:B").setBody(constant("B")); from("direct:c").to("mock:C").setBody(constant("C"));
By default if a timeout occurs the AggregationStrategy is not invoked. However you can implement a specialized version public interface TimeoutAwareAggregationStrategy extends AggregationStrategy { /** * A timeout occurred * * @param oldExchange the oldest exchange (is <tt>null</tt> on first aggregation as we only have the new exchange) * @param index the index * @param total the total * @param timeout the timeout value in millis */ void timeout(Exchange oldExchange, int index, int total, long timeout); This allows you to deal with the timeout in the AggregationStrategy if you really need to.
Using onPrepare to execute custom logic when preparing messagesAvailable as of Camel 2.8 See details at Multicast Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. SplitterThe Splitter from the EIP patterns allows you split a message into a number of pieces and process them individually
As of Camel 2.0, you need to specify a Splitter as split(). In earlier versions of Camel, you need to use splitter(). Options
Exchange propertiesThe following properties are set on each Exchange that are split:
ExamplesThe following example shows how to take a request from the queue:a endpoint the split it into pieces using an Expression, then forward each piece to queue:b Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .split(body(String.class).tokenize("\n")) .to("seda:b"); } }; The splitter can use any Expression language so you could use any of the Languages Supported such as XPath, XQuery, SQL or one of the Scripting Languages to perform the split. e.g. from("activemq:my.queue").split(xpath("//foo/bar")).convertBodyTo(String.class).to("file://some/directory") Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <split> <xpath>/invoice/lineItems</xpath> <to uri="seda:b"/> </split> </route> </camelContext> For further examples of this pattern in use you could look at one of the junit test case Using Tokenizer from Spring XML Extensions*Avaiaible as of Camel 2.0 You can use the tokenizer expression in the Spring DSL to split bodies or headers using a token. This is a common use-case, so we provided a special tokenizer tag for this. <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <split> <tokenize token="@"/> <to uri="mock:result"/> </split> </route> </camelContext> Splitting the body in Spring XML is a bit harder as you need to use the Simple language to dictate this <split> <simple>${body}</simple> <to uri="mock:result"/> </split> What the Splitter returnsCamel 2.2 or older: Camel 2.3 and newer For all versions Parallel execution of distinct 'parts'If you want to execute all parts in parallel you can use special notation of split() with two arguments, where the second one is a boolean flag if processing should be parallel. e.g. XPathBuilder xPathBuilder = new XPathBuilder("//foo/bar"); from("activemq:my.queue").split(xPathBuilder, true).to("activemq:my.parts"); In Camel 2.0 the boolean option has been refactored into a builder method parallelProcessing so its easier to understand what the route does when we use a method instead of true|false. XPathBuilder xPathBuilder = new XPathBuilder("//foo/bar"); from("activemq:my.queue").split(xPathBuilder).parallelProcessing().to("activemq:my.parts"); Stream based
You can split streams by enabling the streaming mode using the streaming builder method.
from("direct:streaming").split(body().tokenize(",")).streaming().to("activemq:my.parts");
You can also supply your custom splitter to use with streaming like this: import static org.apache.camel.builder.ExpressionBuilder.beanExpression; from("direct:streaming") .split(beanExpression(new MyCustomIteratorFactory(), "iterator")) .streaming().to("activemq:my.parts") Streaming big XML payloads using Tokenizer languageAvailable as of Camel 2.9
For example you may have a XML payload structured as follows <orders> <order> <!-- order stuff here --> </order> <order> <!-- order stuff here --> </order> ... <order> <!-- order stuff here --> </order> </orders> Now to split this big file using XPath would cause the entire content to be loaded into memory. So instead we can use the Tokenizer language to do this as follows: from("file:inbox") .split().tokenizeXML("order").streaming() .to("activemq:queue:order"); In XML DSL the route would be as follows: <route> <from uri="file:inbox"/> <split streaming="true"> <tokenize token="order" xml="true"/> <to uri="activemq:queue:order"/> </split> </route> Notice the tokenizeXML method which will split the file using the tag name of the child node, which mean it will grab the content between the <order> and </order> tags (incl. the tokens). So for example a splitted message would be as follows: <order> <!-- order stuff here --> </order> If you want to inherit namespaces from a root/parent tag, then you can do this as well by providing the name of the root/parent tag: <route> <from uri="file:inbox"/> <split streaming="true"> <tokenize token="order" inheritNamespaceTagName="orders" xml="true"/> <to uri="activemq:queue:order"/> </split> </route> And in Java DSL its as follows: from("file:inbox") .split().tokenizeXML("order", "orders").streaming() .to("activemq:queue:order"); Specifying a custom aggregation strategyAvailable as of Camel 2.0 This is specified similar to the Aggregator. Specifying a custom ThreadPoolExecutorYou can customize the underlying ThreadPoolExecutor used in the parallel splitter. In the Java DSL try something like this: XPathBuilder xPathBuilder = new XPathBuilder("//foo/bar"); ExecutorService pool = ... from("activemq:my.queue") .split(xPathBuilder).parallelProcessing().executorService(pool) .to("activemq:my.parts"); Using a Pojo to do the splittingAs the Splitter can use any Expression to do the actual splitting we leverage this fact and use a method expression to invoke a Bean to get the splitted parts.
In the route we define the Expression as a method call to invoke our Bean that we have registered with the id mySplitterBean in the Registry. from("direct:body") // here we use a POJO bean mySplitterBean to do the split of the payload .split().method("mySplitterBean", "splitBody") .to("mock:result"); from("direct:message") // here we use a POJO bean mySplitterBean to do the split of the message // with a certain header value .split().method("mySplitterBean", "splitMessage") .to("mock:result"); And the logic for our Bean is as simple as. Notice we use Camel Bean Binding to pass in the message body as a String object. public class MySplitterBean { /** * The split body method returns something that is iteratable such as a java.util.List. * * @param body the payload of the incoming message * @return a list containing each part splitted */ public List<String> splitBody(String body) { // since this is based on an unit test you can of cause // use different logic for splitting as Camel have out // of the box support for splitting a String based on comma // but this is for show and tell, since this is java code // you have the full power how you like to split your messages List<String> answer = new ArrayList<String>(); String[] parts = body.split(","); for (String part : parts) { answer.add(part); } return answer; } /** * The split message method returns something that is iteratable such as a java.util.List. * * @param header the header of the incoming message with the name user * @param body the payload of the incoming message * @return a list containing each part splitted */ public List<Message> splitMessage(@Header(value = "user") String header, @Body String body) { // we can leverage the Parameter Binding Annotations // http://camel.apache.org/parameter-binding-annotations.html // to access the message header and body at same time, // then create the message that we want, splitter will // take care rest of them. // *NOTE* this feature requires Camel version >= 1.6.1 List<Message> answer = new ArrayList<Message>(); String[] parts = header.split(","); for (String part : parts) { DefaultMessage message = new DefaultMessage(); message.setHeader("user", part); message.setBody(body); answer.add(message); } return answer; } } Split aggregate request/reply sampleThis sample shows how you can split an Exchange, process each splitted message, aggregate and return a combined response to the original caller using request/reply. The route below illustrates this and how the split supports a aggregationStrategy to hold the in progress processed messages: // this routes starts from the direct:start endpoint // the body is then splitted based on @ separator // the splitter in Camel supports InOut as well and for that we need // to be able to aggregate what response we need to send back, so we provide our // own strategy with the class MyOrderStrategy. from("direct:start") .split(body().tokenize("@"), new MyOrderStrategy()) // each splitted message is then send to this bean where we can process it .to("bean:MyOrderService?method=handleOrder") // this is important to end the splitter route as we do not want to do more routing // on each splitted message .end() // after we have splitted and handled each message we want to send a single combined // response back to the original caller, so we let this bean build it for us // this bean will receive the result of the aggregate strategy: MyOrderStrategy .to("bean:MyOrderService?method=buildCombinedResponse") And the OrderService bean is as follows: public static class MyOrderService { private static int counter; /** * We just handle the order by returning a id line for the order */ public String handleOrder(String line) { LOG.debug("HandleOrder: " + line); return "(id=" + ++counter + ",item=" + line + ")"; } /** * We use the same bean for building the combined response to send * back to the original caller */ public String buildCombinedResponse(String line) { LOG.debug("BuildCombinedResponse: " + line); return "Response[" + line + "]"; } } And our custom aggregationStrategy that is responsible for holding the in progress aggregated message that after the splitter is ended will be sent to the buildCombinedResponse method for final processing before the combined response can be returned to the waiting caller. /** * This is our own order aggregation strategy where we can control * how each splitted message should be combined. As we do not want to * loos any message we copy from the new to the old to preserve the * order lines as long we process them */ public static class MyOrderStrategy implements AggregationStrategy { public Exchange aggregate(Exchange oldExchange, Exchange newExchange) { // put order together in old exchange by adding the order from new exchange if (oldExchange == null) { // the first time we aggregate we only have the new exchange, // so we just return it return newExchange; } String orders = oldExchange.getIn().getBody(String.class); String newLine = newExchange.getIn().getBody(String.class); LOG.debug("Aggregate old orders: " + orders); LOG.debug("Aggregate new order: " + newLine); // put orders together separating by semi colon orders = orders + ";" + newLine; // put combined order back on old to preserve it oldExchange.getIn().setBody(orders); // return old as this is the one that has all the orders gathered until now return oldExchange; } } So lets run the sample and see how it works. HandleOrder: A HandleOrder: B Aggregate old orders: (id=1,item=A) Aggregate new order: (id=2,item=B) HandleOrder: C Aggregate old orders: (id=1,item=A);(id=2,item=B) Aggregate new order: (id=3,item=C) BuildCombinedResponse: (id=1,item=A);(id=2,item=B);(id=3,item=C) Response to caller: Response[(id=1,item=A);(id=2,item=B);(id=3,item=C)] Stop processing in case of exceptionAvailable as of Camel 2.1 The Splitter will by default continue to process the entire Exchange even in case of one of the splitted message will thrown an exception during routing. But sometimes you just want Camel to stop and let the exception be propagated back, and let the Camel error handler handle it. You can do this in Camel 2.1 by specifying that it should stop in case of an exception occurred. This is done by the stopOnException option as shown below:
from("direct:start")
.split(body().tokenize(",")).stopOnException()
.process(new MyProcessor())
.to("mock:split");
And using XML DSL you specify it as follows:
<route>
<from uri="direct:start"/>
<split stopOnException="true">
<tokenize token=","/>
<process ref="myProcessor"/>
<to uri="mock:split"/>
</split>
</route>
Using onPrepare to execute custom logic when preparing messagesAvailable as of Camel 2.8 See details at Multicast Sharing unit of workAvailable as of Camel 2.8 The Splitter will by default not share unit of work between the parent exchange and each splitted exchange. This means each sub exchange has its own individual unit of work. For example you may have an use case, where you want to split a big message. And you want to regard that process as an atomic isolated operation that either is a success or failure. In case of a failure you want that big message to be moved into a dead letter queue. To support this use case, you would have to share the unit of work on the Splitter. Here is an example in Java DSL errorHandler(deadLetterChannel("mock:dead").useOriginalMessage() .maximumRedeliveries(3).redeliveryDelay(0)); from("direct:start") .to("mock:a") // share unit of work in the splitter, which tells Camel to propagate failures from // processing the splitted messages back to the result of the splitter, which allows // it to act as a combined unit of work .split(body().tokenize(",")).shareUnitOfWork() .to("mock:b") .to("direct:line") .end() .to("mock:result"); from("direct:line") .to("log:line") .process(new MyProcessor()) .to("mock:line"); Now in this example what would happen is that in case there is a problem processing each sub message, the error handler will kick in (yes error handling still applies for the sub messages). But what doesn't happen is that if a sub message fails all redelivery attempts (its exhausted), then its not moved into that dead letter queue. The reason is that we have shared the unit of work, so the sub message will report the error on the shared unit of work. When the Splitter is done, it checks the state of the shared unit of work and checks if any errors occurred. And if an error occurred it will set the exception on the Exchange and mark it for rollback. The error handler will yet again kick in, as the Exchange has been marked as rollback and it had an exception as well. No redelivery attempts is performed (as it was marked for rollback) and the Exchange will be moved into the dead letter queue. Using this from XML DSL is just as easy as you just have to set the shareUnitOfWork attribute to true: <camelContext errorHandlerRef="dlc" xmlns="http://camel.apache.org/schema/spring"> <!-- define error handler as DLC, with use original message enabled --> <errorHandler id="dlc" type="DeadLetterChannel" deadLetterUri="mock:dead" useOriginalMessage="true"> <redeliveryPolicy maximumRedeliveries="3" redeliveryDelay="0"/> </errorHandler> <route> <from uri="direct:start"/> <to uri="mock:a"/> <!-- share unit of work in the splitter, which tells Camel to propagate failures from processing the splitted messages back to the result of the splitter, which allows it to act as a combined unit of work --> <split shareUnitOfWork="true"> <tokenize token=","/> <to uri="mock:b"/> <to uri="direct:line"/> </split> <to uri="mock:result"/> </route> <!-- route for processing each splitted line --> <route> <from uri="direct:line"/> <to uri="log:line"/> <process ref="myProcessor"/> <to uri="mock:line"/> </route> </camelContext>
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. AggregatorThis applies for Camel version 2.3 or newer. If you use an older version then use this Aggregator link instead. The Aggregator from the EIP patterns allows you to combine a number of messages together into a single message.
A correlation Expression is used to determine the messages which should be aggregated together. If you want to aggregate all messages into a single message, just use a constant expression. An AggregationStrategy is used to combine all the message exchanges for a single correlation key into a single message exchange. Aggregator optionsThe aggregator supports the following options:
Exchange PropertiesThe following properties are set on each aggregated Exchange:
About AggregationStrategyThe AggregationStrategy is used for aggregating the old (lookup by its correlation id) and the new exchanges together into a single exchange. Possible implementations include performing some kind of combining or delta processing, such as adding line items together into an invoice or just using the newest exchange and removing old exchanges such as for state tracking or market data prices; where old values are of little use. Notice the aggregation strategy is a mandatory option and must be provided to the aggregator. Here are a few example AggregationStrategy implementations that should help you create your own custom strategy. //simply combines Exchange String body values using '+' as a delimiter class StringAggregationStrategy implements AggregationStrategy { public Exchange aggregate(Exchange oldExchange, Exchange newExchange) { if (oldExchange == null) { return newExchange; } String oldBody = oldExchange.getIn().getBody(String.class); String newBody = newExchange.getIn().getBody(String.class); oldExchange.getIn().setBody(oldBody + "+" + newBody); return oldExchange; } } //simply combines Exchange body values into an ArrayList<Object> class ArrayListAggregationStrategy implements AggregationStrategy { public Exchange aggregate(Exchange oldExchange, Exchange newExchange) { Object newBody = newExchange.getIn().getBody(); ArrayList<Object> list = null; if (oldExchange == null) { list = new ArrayList<Object>(); list.add(newBody); newExchange.getIn().setBody(list); return newExchange; } else { list = oldExchange.getIn().getBody(ArrayList.class); list.add(newBody); return oldExchange; } } } About completionWhen aggregation Exchanges at some point you need to indicate that the aggregated exchanges is complete, so they can be send out of the aggregator. Camel allows you to indicate completion in various ways as follows:
Notice that all the completion ways are per correlation key. And you can combine them in any way you like. It's basically the first which triggers that wins. So you can use a completion size together with a completion timeout. Only completionTimeout and completionInterval cannot be used at the same time. Notice the completion is a mandatory option and must be provided to the aggregator. If not provided Camel will thrown an Exception on startup. Persistent AggregationRepositoryThe aggregator provides a pluggable repository which you can implement your own org.apache.camel.spi.AggregationRepository. ExamplesSee some examples from the old Aggregator which is somewhat similar to this new aggregator.
Using completionTimeoutIn this example we want to aggregate all incoming messages and after 3 seconds of inactivity we want the aggregation to complete. This is done using the completionTimeout option as shown: from("direct:start") // aggregate all exchanges correlated by the id header. // Aggregate them using the BodyInAggregatingStrategy strategy which // and after 3 seconds of inactivity them timeout and complete the aggregation // and send it to mock:aggregated .aggregate(header("id"), new BodyInAggregatingStrategy()).completionTimeout(3000) .to("mock:aggregated"); And the same example using Spring XML: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <aggregate strategyRef="aggregatorStrategy" completionTimeout="3000"> <correlationExpression> <simple>header.id</simple> </correlationExpression> <to uri="mock:aggregated"/> </aggregate> </route> </camelContext> <bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/> Using completionSizeIn this example we want to aggregate all incoming messages and when we have 3 messages aggregated (in the same correlation group) we want the aggregation to complete. This is done using the completionSize option as shown: from("direct:start") // aggregate all exchanges correlated by the id header. // Aggregate them using the BodyInAggregatingStrategy strategy which // and after 3 messages has been aggregated then complete the aggregation // and send it to mock:aggregated .aggregate(header("id"), new BodyInAggregatingStrategy()).completionSize(3) .to("mock:aggregated"); And the same example using Spring XML: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <aggregate strategyRef="aggregatorStrategy" completionSize="3"> <correlationExpression> <simple>header.id</simple> </correlationExpression> <to uri="mock:aggregated"/> </aggregate> </route> </camelContext> <bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/> Using completionPredicateIn this example we want to aggregate all incoming messages and use a Predicate to determine when we are complete. The Predicate can be evaluated using either the aggregated exchange (default) or the incoming exchange. We will so both situations as examples. We start with the default situation as shown: from("direct:start") // aggregate all exchanges correlated by the id header. // Aggregate them using the BodyInAggregatingStrategy strategy which // and when the aggregated body contains A+B+C then complete the aggregation // and send it to mock:aggregated .aggregate(header("id"), new BodyInAggregatingStrategy()).completionPredicate(body().contains("A+B+C")) .to("mock:aggregated"); And the same example using Spring XML: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <aggregate strategyRef="aggregatorStrategy"> <correlationExpression> <simple>header.id</simple> </correlationExpression> <completionPredicate> <simple>${body} contains 'A+B+C'</simple> </completionPredicate> <to uri="mock:aggregated"/> </aggregate> </route> </camelContext> <bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/> And the other situation where we use the eagerCheckCompletion option to tell Camel to use the incoming Exchange. Notice how we can just test in the completion predicate that the incoming message is the END message: from("direct:start") // aggregate all exchanges correlated by the id header. // Aggregate them using the BodyInAggregatingStrategy strategy // do eager checking which means the completion predicate will use the incoming exchange // which allows us to trigger completion when a certain exchange arrived which is the // END message .aggregate(header("id"), new BodyInAggregatingStrategy()) .eagerCheckCompletion().completionPredicate(body().isEqualTo("END")) .to("mock:aggregated"); And the same example using Spring XML: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <aggregate strategyRef="aggregatorStrategy" eagerCheckCompletion="true"> <correlationExpression> <simple>header.id</simple> </correlationExpression> <completionPredicate> <simple>${body} == 'END'</simple> </completionPredicate> <to uri="mock:aggregated"/> </aggregate> </route> </camelContext> <bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/> Using dynamic completionTimeoutIn this example we want to aggregate all incoming messages and after a period of inactivity we want the aggregation to complete. The period should be computed at runtime based on the timeout header in the incoming messages. This is done using the completionTimeout option as shown: from("direct:start") // aggregate all exchanges correlated by the id header. // Aggregate them using the BodyInAggregatingStrategy strategy which // and the timeout header contains the timeout in millis of inactivity them timeout and complete the aggregation // and send it to mock:aggregated .aggregate(header("id"), new BodyInAggregatingStrategy()).completionTimeout(header("timeout")) .to("mock:aggregated"); And the same example using Spring XML: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <aggregate strategyRef="aggregatorStrategy"> <correlationExpression> <simple>header.id</simple> </correlationExpression> <completionTimeout> <header>timeout</header> </completionTimeout> <to uri="mock:aggregated"/> </aggregate> </route> </camelContext> <bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/> Note: You can also add a fixed timeout value and Camel will fallback to use this value if the dynamic value was null or 0. Using dynamic completionSizeIn this example we want to aggregate all incoming messages based on a dynamic size per correlation key. The size is computed at runtime based on the mySize header in the incoming messages. This is done using the completionSize option as shown: from("direct:start") // aggregate all exchanges correlated by the id header. // Aggregate them using the BodyInAggregatingStrategy strategy which // and the header mySize determines the number of aggregated messages should trigger the completion // and send it to mock:aggregated .aggregate(header("id"), new BodyInAggregatingStrategy()).completionSize(header("mySize")) .to("mock:aggregated"); And the same example using Spring XML: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <aggregate strategyRef="aggregatorStrategy"> <correlationExpression> <simple>header.id</simple> </correlationExpression> <completionSize> <header>mySize</header> </completionSize> <to uri="mock:aggregated"/> </aggregate> </route> </camelContext> <bean id="aggregatorStrategy" class="org.apache.camel.processor.BodyInAggregatingStrategy"/> Note: You can also add a fixed size value and Camel will fallback to use this value if the dynamic value was null or 0. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Manually Force the Completion of All Aggregated Exchanges ImmediatelyAvailable as of Camel 2.9 See also
ResequencerThe Resequencer from the EIP patterns allows you to reorganise messages based on some comparator. By default in Camel we use an Expression to create the comparator; so that you can compare by a message header or the body or a piece of a message etc.
Camel supports two resequencing algorithms:
By default the Resequencer does not support duplicate messages and will only keep the last message, in case a message arrives with the same message expression. However in the batch mode you can enable it to allow duplicates. Batch ResequencingThe following example shows how to use the batch-processing resequencer so that messages are sorted in order of the body() expression. That is messages are collected into a batch (either by a maximum number of messages per batch or using a timeout) then they are sorted in order and then sent out to their output. Using the Fluent Builders from("direct:start") .resequence().body() .to("mock:result"); This is equvalent to from("direct:start") .resequence(body()).batch() .to("mock:result"); The batch-processing resequencer can be further configured via the size() and timeout() methods. from("direct:start") .resequence(body()).batch().size(300).timeout(4000L) .to("mock:result") This sets the batch size to 300 and the batch timeout to 4000 ms (by default, the batch size is 100 and the timeout is 1000 ms). Alternatively, you can provide a configuration object. from("direct:start") .resequence(body()).batch(new BatchResequencerConfig(300, 4000L)) .to("mock:result") So the above example will reorder messages from endpoint direct:a in order of their bodies, to the endpoint mock:result.
resequencer(header("mySeqNo"))
for example to reorder messages using a custom sequence number in the header mySeqNo. You can of course use many different Expression languages such as XPath, XQuery, SQL or various Scripting Languages. Using the Spring XML Extensions <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start" /> <resequence> <simple>body</simple> <to uri="mock:result" /> <!-- batch-config can be ommitted for default (batch) resequencer settings --> <batch-config batchSize="300" batchTimeout="4000" /> </resequence> </route> </camelContext> Allow DuplicatesAvailable as of Camel 2.4 In the batch mode, you can now allow duplicates. In Java DSL there is a allowDuplicates() method and in Spring XML there is an allowDuplicates=true attribute on the <batch-config/> you can use to enable it. ReverseAvailable as of Camel 2.4 In the batch mode, you can now reverse the expression ordering. By default the order is based on 0..9,A..Z, which would let messages with low numbers be ordered first, and thus also also outgoing first. In some cases you want to reverse order, which is now possible. In Java DSL there is a reverse() method and in Spring XML there is an reverse=true attribute on the <batch-config/> you can use to enable it. Resequence JMS messages based on JMSPriorityAvailable as of Camel 2.4 It's now much easier to use the Resequencer to resequence messages from JMS queues based on JMSPriority. For that to work you need to use the two new options allowDuplicates and reverse. from("jms:queue:foo") // sort by JMSPriority by allowing duplicates (message can have same JMSPriority) // and use reverse ordering so 9 is first output (most important), and 0 is last // use batch mode and fire every 3th second .resequence(header("JMSPriority")).batch().timeout(3000).allowDuplicates().reverse() .to("mock:result"); Notice this is only possible in the batch mode of the Resequencer. Ignore invalid exchangesAvailable as of Camel 2.9 The Resequencer EIP will from Camel 2.9 onwards throw a CamelExchangeException if the incoming Exchange is not valid for the resequencer - ie. the expression cannot be evaluated, such as a missing header. You can use the option ignoreInvalidExchanges to ignore these exceptions which means the Resequencer will then skip the invalid Exchange. from("direct:start") .resequence(header("seqno")).batch().timeout(1000) // ignore invalid exchanges (they are discarded) .ignoreInvalidExchanges() .to("mock:result"); This option is available for both batch and stream resequencer. Stream ResequencingThe next example shows how to use the stream-processing resequencer. Messages are re-ordered based on their sequence numbers given by a seqnum header using gap detection and timeouts on the level of individual messages. Using the Fluent Builders from("direct:start").resequence(header("seqnum")).stream().to("mock:result"); The stream-processing resequencer can be further configured via the capacity() and timeout() methods. from("direct:start") .resequence(header("seqnum")).stream().capacity(5000).timeout(4000L) .to("mock:result") This sets the resequencer's capacity to 5000 and the timeout to 4000 ms (by default, the capacity is 100 and the timeout is 1000 ms). Alternatively, you can provide a configuration object. from("direct:start") .resequence(header("seqnum")).stream(new StreamResequencerConfig(5000, 4000L)) .to("mock:result") The stream-processing resequencer algorithm is based on the detection of gaps in a message stream rather than on a fixed batch size. Gap detection in combination with timeouts removes the constraint of having to know the number of messages of a sequence (i.e. the batch size) in advance. Messages must contain a unique sequence number for which a predecessor and a successor is known. For example a message with the sequence number 3 has a predecessor message with the sequence number 2 and a successor message with the sequence number 4. The message sequence 2,3,5 has a gap because the sucessor of 3 is missing. The resequencer therefore has to retain message 5 until message 4 arrives (or a timeout occurs). If the maximum time difference between messages (with successor/predecessor relationship with respect to the sequence number) in a message stream is known, then the resequencer's timeout parameter should be set to this value. In this case it is guaranteed that all messages of a stream are delivered in correct order to the next processor. The lower the timeout value is compared to the out-of-sequence time difference the higher is the probability for out-of-sequence messages delivered by this resequencer. Large timeout values should be supported by sufficiently high capacity values. The capacity parameter is used to prevent the resequencer from running out of memory. By default, the stream resequencer expects long sequence numbers but other sequence numbers types can be supported as well by providing a custom expression. public class MyFileNameExpression implements Expression { public String getFileName(Exchange exchange) { return exchange.getIn().getBody(String.class); } public Object evaluate(Exchange exchange) { // parser the file name with YYYYMMDD-DNNN pattern String fileName = getFileName(exchange); String[] files = fileName.split("-D"); Long answer = Long.parseLong(files[0]) * 1000 + Long.parseLong(files[1]); return answer; } public <T> T evaluate(Exchange exchange, Class<T> type) { Object result = evaluate(exchange); return exchange.getContext().getTypeConverter().convertTo(type, result); } } from("direct:start").resequence(new MyFileNameExpression()).stream().timeout(100).to("mock:result"); or custom comparator via the comparator() method ExpressionResultComparator<Exchange> comparator = new MyComparator(); from("direct:start") .resequence(header("seqnum")).stream().comparator(comparator) .to("mock:result"); or via a StreamResequencerConfig object. ExpressionResultComparator<Exchange> comparator = new MyComparator(); StreamResequencerConfig config = new StreamResequencerConfig(100, 1000L, comparator); from("direct:start") .resequence(header("seqnum")).stream(config) .to("mock:result"); Using the Spring XML Extensions <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <resequence> <simple>in.header.seqnum</simple> <to uri="mock:result" /> <stream-config capacity="5000" timeout="4000"/> </resequence> </route> </camelContext> Further ExamplesFor further examples of this pattern in use you could look at the batch-processing resequencer junit test case and the stream-processing resequencer junit test case Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Composed Message ProcessorThe Composed Message Processor from the EIP patterns allows you to process a composite message by splitting it up, routing the sub-messages to appropriate destinations and the re-aggregating the responses back into a single message.
Available in Camel 1.5. ExampleIn this example we want to check that a multipart order can be filled. Each part of the order requires a check at a different inventory. // split up the order so individual OrderItems can be validated by the appropriate bean from("direct:start") .split().body() .choice() .when().method("orderItemHelper", "isWidget") .to("bean:widgetInventory") .otherwise() .to("bean:gadgetInventory") .end() .to("seda:aggregate"); // collect and re-assemble the validated OrderItems into an order again from("seda:aggregate") .aggregate(new MyOrderAggregationStrategy()).header("orderId").completionTimeout(1000L) .to("mock:result"); Using the Spring XML Extensions <route> <from uri="direct:start"/> <split> <simple>body</simple> <choice> <when> <method bean="orderItemHelper" method="isWidget"/> <to uri="bean:widgetInventory"/> </when> <otherwise> <to uri="bean:gadgetInventory"/> </otherwise> </choice> <to uri="seda:aggregate"/> </split> </route> <route> <from uri="seda:aggregate"/> <aggregate strategyRef="myOrderAggregatorStrategy" completionTimeout="1000"> <correlationExpression> <simple>header.orderId</simple> </correlationExpression> <to uri="mock:result"/> </aggregate> </route> To do this we split up the order using a Splitter. The Splitter then sends individual OrderItems to a Content Based Router which checks the item type. Widget items get sent for checking in the widgetInventory bean and gadgets get sent to the gadgetInventory bean. Once these OrderItems have been validated by the appropriate bean, they are sent on to the Aggregator which collects and re-assembles the validated OrderItems into an order again. When an order is sent it contains a header with the order id. We use this fact when we aggregate, as we configure this .header("orderId") on the aggregate DSL to instruct Camel to use the header with the key orderId as correlation expression. For full details, check the example source here: camel-core/src/test/java/org/apache/camel/processor/ComposedMessageProcessorTest.java Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Scatter-GatherThe Scatter-Gather from the EIP patterns allows you to route messages to a number of dynamically specified recipients and re-aggregate the responses back into a single message.
Available in Camel 1.5. Dynamic Scatter-Gather ExampleIn this example we want to get the best quote for beer from several different vendors. We use a dynamic Recipient List to get the request for a quote to all vendors and an Aggregator to pick the best quote out of all the responses. The routes for this are defined as: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <recipientList> <header>listOfVendors</header> </recipientList> </route> <route> <from uri="seda:quoteAggregator"/> <aggregate strategyRef="aggregatorStrategy" completionTimeout="1000"> <correlationExpression> <header>quoteRequestId</header> </correlationExpression> <to uri="mock:result"/> </aggregate> </route> </camelContext> So in the first route you see that the Recipient List is looking at the listOfVendors header for the list of recipients. So, we need to send a message like Map<String, Object> headers = new HashMap<String, Object>(); headers.put("listOfVendors", "bean:vendor1, bean:vendor2, bean:vendor3"); headers.put("quoteRequestId", "quoteRequest-1"); template.sendBodyAndHeaders("direct:start", "<quote_request item=\"beer\"/>", headers); This message will be distributed to the following Endpoints: bean:vendor1, bean:vendor2, and bean:vendor3. These are all beans which look like public class MyVendor { private int beerPrice; @Produce(uri = "seda:quoteAggregator") private ProducerTemplate quoteAggregator; public MyVendor(int beerPrice) { this.beerPrice = beerPrice; } public void getQuote(@XPath("/quote_request/@item") String item, Exchange exchange) throws Exception { if ("beer".equals(item)) { exchange.getIn().setBody(beerPrice); quoteAggregator.send(exchange); } else { throw new Exception("No quote available for " + item); } } } and are loaded up in Spring like <bean id="aggregatorStrategy" class="org.apache.camel.spring.processor.scattergather.LowestQuoteAggregationStrategy"/> <bean id="vendor1" class="org.apache.camel.spring.processor.scattergather.MyVendor"> <constructor-arg> <value>1</value> </constructor-arg> </bean> <bean id="vendor2" class="org.apache.camel.spring.processor.scattergather.MyVendor"> <constructor-arg> <value>2</value> </constructor-arg> </bean> <bean id="vendor3" class="org.apache.camel.spring.processor.scattergather.MyVendor"> <constructor-arg> <value>3</value> </constructor-arg> </bean> Each bean is loaded with a different price for beer. When the message is sent to each bean endpoint, it will arrive at the MyVendor.getQuote method. This method does a simple check whether this quote request is for beer and then sets the price of beer on the exchange for retrieval at a later step. The message is forwarded on to the next step using POJO Producing (see the @Produce annotation). At the next step we want to take the beer quotes from all vendors and find out which one was the best (i.e. the lowest!). To do this we use an Aggregator with a custom aggregation strategy. The Aggregator needs to be able to compare only the messages from this particular quote; this is easily done by specifying a correlationExpression equal to the value of the quoteRequestId header. As shown above in the message sending snippet, we set this header to quoteRequest-1. This correlation value should be unique or you may include responses that are not part of this quote. To pick the lowest quote out of the set, we use a custom aggregation strategy like public class LowestQuoteAggregationStrategy implements AggregationStrategy { public Exchange aggregate(Exchange oldExchange, Exchange newExchange) { // the first time we only have the new exchange if (oldExchange == null) { return newExchange; } if (oldExchange.getIn().getBody(int.class) < newExchange.getIn().getBody(int.class)) { return oldExchange; } else { return newExchange; } } } Finally, we expect to get the lowest quote of $1 out of $1, $2, and $3. result.expectedBodiesReceived(1); // expect the lowest quote
You can find the full example source here: camel-spring/src/test/java/org/apache/camel/spring/processor/scattergather/ Static Scatter-Gather ExampleYou can lock down which recipients are used in the Scatter-Gather by using a static Recipient List. It looks something like this from("direct:start").multicast().to("seda:vendor1", "seda:vendor2", "seda:vendor3"); from("seda:vendor1").to("bean:vendor1").to("seda:quoteAggregator"); from("seda:vendor2").to("bean:vendor2").to("seda:quoteAggregator"); from("seda:vendor3").to("bean:vendor3").to("seda:quoteAggregator"); from("seda:quoteAggregator") .aggregate(header("quoteRequestId"), new LowestQuoteAggregationStrategy()).to("mock:result") A full example of the static Scatter-Gather configuration can be found in the Loan Broker Example. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Routing SlipThe Routing Slip from the EIP patterns allows you to route a message consecutively through a series of processing steps where the sequence of steps is not known at design time and can vary for each message.
Options
ExampleThe following route will take any messages sent to the Apache ActiveMQ queue SomeQueue and pass them into the Routing Slip pattern. from("activemq:SomeQueue").routingSlip("headerName"); Messages will be checked for the existance of the "headerName" header. The value of this header should be a comma-delimited list of endpoint URIs you wish the message to be routed to. The Message will be routed in a pipeline fashion (i.e. one after the other). Note: In Camel 1.x the default header name routingSlipHeader has been @deprecated and is removed in Camel 2.0. We feel that the DSL needed to express, the header it uses to locate the destinations, directly in the DSL to not confuse readers. So the header name must be provided. From Camel 2.5 the Routing Slip will set a property (Exchange.SLIP_ENDPOINT) on the Exchange which contains the current endpoint as it advanced though the slip. This allows you to know how far we have processed in the slip. The Routing Slip will compute the slip beforehand which means, the slip is only computed once. If you need to compute the slip on-the-fly then use the Dynamic Router pattern instead. Configuration optionsHere we set the header name and the URI delimiter to something different. Using the Fluent Builders from("direct:c").routingSlip(header("aRoutingSlipHeader"), "#"); Using the Spring XML Extensions <camelContext id="buildRoutingSlip" xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:c"/> <routingSlip headerName="aRoutingSlipHeader" uriDelimiter="#"/> </route> </camelContext> Ignore invalid endpointsAvailable as of Camel 2.3 The Routing Slip now supports ignoreInvalidEndpoints which the Recipient List also supports. You can use it to skip endpoints which is invalid.
from("direct:a").routingSlip("myHeader").ignoreInvalidEndpoints();
And in Spring XML its an attribute on the recipient list tag.
<route>
<from uri="direct:a"/>
<routingSlip headerName="myHeader" ignoreInvalidEndpoints="true"/>
</route>
Then lets say the myHeader contains the following two endpoints direct:foo,xxx:bar. The first endpoint is valid and works. However the 2nd is invalid and will just be ignored. Camel logs at INFO level about, so you can see why the endpoint was invalid. Expression supportingAvailable as of Camel 2.4 The Routing Slip now supports to take the expression parameter as the Recipient List does. You can tell the camel the expression that you want to use to get the routing slip.
from("direct:a").routingSlip(header("myHeader")).ignoreInvalidEndpoints();
And in Spring XML its an attribute on the recipient list tag.
<route>
<from uri="direct:a"/>
<!--NOTE from Camel 2.4.0, you need to specify the expression element inside of the routingSlip element -->
<routingSlip ignoreInvalidEndpoints="true">
<header>myHeader</header>
</routingSlip>
</route>
Further ExamplesFor further examples of this pattern in use you could look at the routing slip test cases. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. ThrottlerThe Throttler Pattern allows you to ensure that a specific endpoint does not get overloaded, or that we don't exceed an agreed SLA with some external service. Options
ExamplesUsing the Fluent Builders from("seda:a").throttle(3).timePeriodMillis(10000).to("log:result", "mock:result"); So the above example will throttle messages all messages received on seda:a before being sent to mock:result ensuring that a maximum of 3 messages are sent in any 10 second window. Note that typically you would often use the default time period of a second. So to throttle requests at 100 requests per second between two endpoints it would look more like this... from("seda:a").throttle(100).to("seda:b"); For further examples of this pattern in use you could look at the junit test case Using the Spring XML Extensions Camel 2.7.x or older<route> <from uri="seda:a" /> <throttle maximumRequestsPerPeriod="3" timePeriodMillis="10000"> <to uri="mock:result" /> </throttle> </route> Camel 2.8 onwardsIn Camel 2.8 onwards you must set the maximum period as an Expression as shown below where we use a Constant expression: <route> <from uri="seda:a"/> <!-- throttle 3 messages per 10 sec --> <throttle timePeriodMillis="10000"> <constant>3</constant> <to uri="mock:result"/> </throttle> </route> Dynamically changing maximum requests per periodAvailable os of Camel 2.8 <route> <from uri="direct:expressionHeader"/> <throttle timePeriodMillis="500"> <!-- use a header to determine how many messages to throttle per 0.5 sec --> <header>throttleValue</header> <to uri="mock:result"/> </throttle> </route> Asynchronous delayingAvailable as of Camel 2.4 You can let the Throttler use non blocking asynchronous delaying, which means Camel will use a scheduler to schedule a task to be executed in the future. The task will then continue routing. This allows the caller thread to not block and be able to service other messages etc. from("seda:a").throttle(100).asyncDelayed().to("seda:b"); Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Sampling ThrottlerAvailable as of Camel 2.1 A sampling throttler allows you to extract a sample of the exchanges from the traffic through a route. Will by default use a sample period of 1 seconds. Options
SamplesYou use this EIP with the sample DSL as show in these samples. Using the Fluent Builders from("direct:sample") .sample() .to("mock:result"); from("direct:sample-configured") .sample(1, TimeUnit.SECONDS) .to("mock:result"); from("direct:sample-configured-via-dsl") .sample().samplePeriod(1).timeUnits(TimeUnit.SECONDS) .to("mock:result"); from("direct:sample-messageFrequency") .sample(10) .to("mock:result"); from("direct:sample-messageFrequency-via-dsl") .sample().sampleMessageFrequency(5) .to("mock:result"); Using the Spring XML Extensions <route> <from uri="direct:sample"/> <sample samplePeriod="1" units="seconds"> <to uri="mock:result"/> </sample> </route> <route> <from uri="direct:sample-messageFrequency"/> <sample messageFrequency="10"> <to uri="mock:result"/> </sample> </route> <route> <from uri="direct:sample-messageFrequency-via-dsl"/> <sample messageFrequency="5"> <to uri="mock:result"/> </sample> </route> And since it uses a default of 1 second you can omit this configuration in case you also want to use 1 second <route> <from uri="direct:sample"/> <!-- will by default use 1 second period --> <sample> <to uri="mock:result"/> </sample> </route> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. See AlsoDelayerThe Delayer Pattern allows you to delay the delivery of messages to some destination.
Options
Using the Fluent Builders from("seda:b").delay(1000).to("mock:result"); So the above example will delay all messages received on seda:b 1 second before sending them to mock:result. You can of course use many different Expression languages such as XPath, XQuery, SQL or various Scripting Languages. You can just delay things a fixed amount of time from the point at which the delayer receives the message. For example to delay things 2 seconds delayer(2000) The above assume that the delivery order is maintained and that the messages are delivered in delay order. If you want to reorder the messages based on delivery time, you can use the Resequencer with this pattern. For example from("activemq:someQueue").resequencer(header("MyDeliveryTime")).delay("MyRedeliveryTime").to("activemq:aDelayedQueue"); Camel 2.0 - Spring DSLThe sample below demonstrates the delay in Spring DSL: <bean id="myDelayBean" class="org.apache.camel.processor.MyDelayCalcBean"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <delay> <header>MyDelay</header> </delay> <to uri="mock:result"/> </route> <route> <from uri="seda:b"/> <delay> <constant>1000</constant> </delay> <to uri="mock:result"/> </route> <route> <from uri="seda:c"/> <delay> <method ref="myDelayBean" method="delayMe"/> </delay> <to uri="mock:result"/> </route> </camelContext> Camel 1.x - Spring DSLThe delayer is using slightly different names in Camel 1.x: <delayer> <delayTime>3000</delayTime> </expression> </delayer> The empty tag </expression> is needed to fulfill the XSD validation as its an optional element and we use JAXB annotations to generated the XSD in Camel and some combinations is hard to auto generate with optional elements. For further examples of this pattern in use you could look at the junit test case Asynchronous delayingAvailable as of Camel 2.4 You can let the Delayer use non blocking asynchronous delaying, which means Camel will use a scheduler to schedule a task to be executed in the future. The task will then continue routing. This allows the caller thread to not block and be able to service other messages etc. From Java DSLYou use the asyncDelayed() to enable the async behavior. from("activemq:queue:foo").delay(1000).asyncDelayed().to("activemq:aDelayedQueue"); From Spring XMLYou use the asyncDelayed="true" attribute to enable the async behavior. <route> <from uri="activemq:queue:foo"/> <delay asyncDelayed="true"> <constant>1000</constant> </delay> <to uri="activemq:aDealyedQueue"/> </route> Creating a custom delayYou can use an expression to determine when to send a message using something like this from("activemq:foo"). delay().method("someBean", "computeDelay"). to("activemq:bar"); then the bean would look like this... public class SomeBean { public long computeDelay() { long delay = 0; // use java code to compute a delay value in millis return delay; } } Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. See AlsoLoad BalancerThe Load Balancer Pattern allows you to delegate to one of a number of endpoints using a variety of different load balancing policies. Built-in load balancing policiesCamel provides the following policies out-of-the-box:
Round RobinThe round robin load balancer is not meant to work with failover, for that you should use the dedicated failover load balancer. The round robin load balancer will only change to next endpoint per message. The round robin load balancer is stateful as it keeps state of which endpoint to use next time. Using the Fluent Builders from("direct:start").loadBalance(). roundRobin().to("mock:x", "mock:y", "mock:z"); Using the Spring configuration <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <loadBalance> <roundRobin/> <to uri="mock:x"/> <to uri="mock:y"/> <to uri="mock:z"/> </loadBalance> </route> </camelContext> The above example loads balance requests from direct:start to one of the available mock endpoint instances, in this case using a round robin policy. FailoverAvailable as of Camel 2.0
Failover offers the following options:
Camel 2.2 or older behavior Camel 2.3 onwards behavior
Here is a sample to failover only if a IOException related exception was thrown: from("direct:start") // here we will load balance if IOException was thrown // any other kind of exception will result in the Exchange as failed // to failover over any kind of exception we can just omit the exception // in the failOver DSL .loadBalance().failover(IOException.class) .to("direct:x", "direct:y", "direct:z"); You can specify multiple exceptions to failover as the option is varargs, for instance: // enable redelivery so failover can react errorHandler(defaultErrorHandler().maximumRedeliveries(5)); from("direct:foo"). loadBalance().failover(IOException.class, MyOtherException.class) .to("direct:a", "direct:b"); Using failover in Spring DSLFailover can also be used from Spring DSL and you configure it as: <route errorHandlerRef="myErrorHandler"> <from uri="direct:foo"/> <loadBalance> <failover> <exception>java.io.IOException</exception> <exception>com.mycompany.MyOtherException</exception> </failover> <to uri="direct:a"/> <to uri="direct:b"/> </loadBalance> </route> Using failover in round robin modeAn example using Java DSL: from("direct:start") // Use failover load balancer in stateful round robin mode // which mean it will failover immediately in case of an exception // as it does NOT inherit error handler. It will also keep retrying as // its configured to newer exhaust. .loadBalance().failover(-1, false, true). to("direct:bad", "direct:bad2", "direct:good", "direct:good2"); And the same example using Spring XML: <route> <from uri="direct:start"/> <loadBalance> <!-- failover using stateful round robin, which will keep retrying forever those 4 endpoints until success. You can set the maximumFailoverAttempt to break out after X attempts --> <failover roundRobin="true"/> <to uri="direct:bad"/> <to uri="direct:bad2"/> <to uri="direct:good"/> <to uri="direct:good2"/> </loadBalance> </route>
Weighted Round-Robin and Random Load BalancingAvailable as of Camel 2.5 In many enterprise environments where server nodes of unequal processing power & performance characteristics are utilized to host services and processing endpoints, it is frequently necessary to distribute processing load based on their individual server capabilities so that some endpoints are not unfairly burdened with requests. Obviously simple round-robin or random load balancing do not alleviate problems of this nature. A Weighted Round-Robin and/or Weighted Random load balancer can be used to address this problem. The weighted load balancing policy allows you to specify a processing load distribution ratio for each server with respect to others. You can specify this as a positive processing weight for each server. A larger number indicates that the server can handle a larger load. The weight is utilized to determine the payload distribution ratio to different processing endpoints with respect to others.
The parameters that can be used are In Camel 2.5
Available In Camel 2.6
Using Weighted round-robin & random load balancingIn Camel 2.5 An example using Java DSL: ArrayList<integer> distributionRatio = new ArrayList<integer>(); distributionRatio.add(4); distributionRatio.add(2); distributionRatio.add(1); // round-robin from("direct:start") .loadBalance().weighted(true, distributionRatio) .to("mock:x", "mock:y", "mock:z"); //random from("direct:start") .loadBalance().weighted(false, distributionRatio) .to("mock:x", "mock:y", "mock:z"); And the same example using Spring XML:
<route>
<from uri="direct:start"/>
<loadBalance>
<weighted roundRobin="false" distributionRatio="4 2 1"/>
<to uri="mock:x"/>
<to uri="mock:y"/>
<to uri="mock:z"/>
</loadBalance>
</route>
Available In Camel 2.6 An example using Java DSL: // round-robin from("direct:start") .loadBalance().weighted(true, "4:2:1" distributionRatioDelimiter=":") .to("mock:x", "mock:y", "mock:z"); //random from("direct:start") .loadBalance().weighted(false, "4,2,1") .to("mock:x", "mock:y", "mock:z"); And the same example using Spring XML:
<route>
<from uri="direct:start"/>
<loadBalance>
<weighted roundRobin="false" distributionRatio="4-2-1" distributionRatioDelimiter="-" />
<to uri="mock:x"/>
<to uri="mock:y"/>
<to uri="mock:z"/>
</loadBalance>
</route>
Custom Load BalancerYou can use a custom load balancer (eg your own implementation) also. An example using Java DSL: from("direct:start") // using our custom load balancer .loadBalance(new MyLoadBalancer()) .to("mock:x", "mock:y", "mock:z"); And the same example using XML DSL: <!-- this is the implementation of our custom load balancer --> <bean id="myBalancer" class="org.apache.camel.processor.CustomLoadBalanceTest$MyLoadBalancer"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <loadBalance> <!-- refer to my custom load balancer --> <custom ref="myBalancer"/> <!-- these are the endpoints to balancer --> <to uri="mock:x"/> <to uri="mock:y"/> <to uri="mock:z"/> </loadBalance> </route> </camelContext> Notice in the XML DSL above we use <custom> which is only available in Camel 2.8 onwards. In older releases you would have to do as follows instead:
<loadBalance ref="myBalancer">
<!-- these are the endpoints to balancer -->
<to uri="mock:x"/>
<to uri="mock:y"/>
<to uri="mock:z"/>
</loadBalance>
To implement a custom load balancer you can extend some support classes such as LoadBalancerSupport and SimpleLoadBalancerSupport. The former supports the asynchronous routing engine, and the latter does not. Here is an example: Custom load balancer implementation public static class MyLoadBalancer extends LoadBalancerSupport { public boolean process(Exchange exchange, AsyncCallback callback) { String body = exchange.getIn().getBody(String.class); try { if ("x".equals(body)) { getProcessors().get(0).process(exchange); } else if ("y".equals(body)) { getProcessors().get(1).process(exchange); } else { getProcessors().get(2).process(exchange); } } catch (Throwable e) { exchange.setException(e); } callback.done(true); return true; } } Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. MulticastThe Multicast allows to route the same message to a number of endpoints and process them in a different way. The main difference between the Multicast and Splitter is that Splitter will split the message into several pieces but the Multicast will not modify the request message. Options
ExampleThe following example shows how to take a request from the direct:a endpoint , then multicast these request to direct:x, direct:y, direct:z. Using the Fluent Builders from("direct:a").multicast().to("direct:x", "direct:y", "direct:z"); By default Multicast invokes each endpoint sequentially. If parallel processing is desired, simply use from("direct:a").multicast().parallelProcessing().to("direct:x", "direct:y", "direct:z"); In case of using InOut MEP, an AggregationStrategy is used for aggregating all reply messages. The default is to only use the latest reply message and discard any earlier replies. The aggregation strategy is configurable: from("direct:start") .multicast(new MyAggregationStrategy()) .parallelProcessing().timeout(500).to("direct:a", "direct:b", "direct:c") .end() .to("mock:result"); Stop processing in case of exceptionAvailable as of Camel 2.1 The Multicast will by default continue to process the entire Exchange even in case one of the multicasted messages will thrown an exception during routing. But sometimes you just want Camel to stop and let the exception be propagated back, and let the Camel error handler handle it. You can do this in Camel 2.1 by specifying that it should stop in case of an exception occurred. This is done by the stopOnException option as shown below:
from("direct:start")
.multicast()
.stopOnException().to("direct:foo", "direct:bar", "direct:baz")
.end()
.to("mock:result");
from("direct:foo").to("mock:foo");
from("direct:bar").process(new MyProcessor()).to("mock:bar");
from("direct:baz").to("mock:baz");
And using XML DSL you specify it as follows:
<route>
<from uri="direct:start"/>
<multicast stopOnException="true">
<to uri="direct:foo"/>
<to uri="direct:bar"/>
<to uri="direct:baz"/>
</multicast>
<to uri="mock:result"/>
</route>
<route>
<from uri="direct:foo"/>
<to uri="mock:foo"/>
</route>
<route>
<from uri="direct:bar"/>
<process ref="myProcessor"/>
<to uri="mock:bar"/>
</route>
<route>
<from uri="direct:baz"/>
<to uri="mock:baz"/>
</route>
Using onPrepare to execute custom logic when preparing messagesAvailable as of Camel 2.8 The Multicast will copy the source Exchange and multicast each copy. However the copy is a shallow copy, so in case you have mutateable message bodies, then any changes will be visible by the other copied messages. If you want to use a deep clone copy then you need to use a custom onPrepare which allows you to do this using the Processor interface. Notice the onPrepare can be used for any kind of custom logic which you would like to execute before the Exchange is being multicasted.
For example if you have a mutable message body as this Animal class: Animal public class Animal implements Serializable { private static final long serialVersionUID = 1L; private int id; private String name; public Animal() { } public Animal(int id, String name) { this.id = id; this.name = name; } public Animal deepClone() { Animal clone = new Animal(); clone.setId(getId()); clone.setName(getName()); return clone; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public String toString() { return id + " " + name; } } Then we can create a deep clone processor which clones the message body: AnimalDeepClonePrepare public class AnimalDeepClonePrepare implements Processor { public void process(Exchange exchange) throws Exception { Animal body = exchange.getIn().getBody(Animal.class); // do a deep clone of the body which wont affect when doing multicasting Animal clone = body.deepClone(); exchange.getIn().setBody(clone); } } Then we can use the AnimalDeepClonePrepare class in the Multicast route using the onPrepare option as shown: Multicast using onPrepare from("direct:start") .multicast().onPrepare(new AnimalDeepClonePrepare()).to("direct:a").to("direct:b"); And the same example in XML DSL Multicast using onPrepare <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <!-- use on prepare with multicast --> <multicast onPrepareRef="animalDeepClonePrepare"> <to uri="direct:a"/> <to uri="direct:b"/> </multicast> </route> <route> <from uri="direct:a"/> <process ref="processorA"/> <to uri="mock:a"/> </route> <route> <from uri="direct:b"/> <process ref="processorB"/> <to uri="mock:b"/> </route> </camelContext> <!-- the on prepare Processor which performs the deep cloning --> <bean id="animalDeepClonePrepare" class="org.apache.camel.processor.AnimalDeepClonePrepare"/> <!-- processors used for the last two routes, as part of unit test --> <bean id="processorA" class="org.apache.camel.processor.MulticastOnPrepareTest$ProcessorA"/> <bean id="processorB" class="org.apache.camel.processor.MulticastOnPrepareTest$ProcessorB"/> Notice the onPrepare option is also available on other EIPs such as Splitter, Recipient List, and Wire Tap. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. LoopThe Loop allows for processing a message a number of times, possibly in a different way for each iteration. Useful mostly during testing.
Options
Exchange propertiesFor each iteration two properties are set on the Exchange. Processors can rely on these properties to process the Message in different ways.
ExamplesThe following example shows how to take a request from the direct:x endpoint, then send the message repetitively to mock:result. The number of times the message is sent is either passed as an argument to loop(), or determined at runtime by evaluating an expression. The expression must evaluate to an int, otherwise a RuntimeCamelException is thrown. Using the Fluent Builders Pass loop count as an argument from("direct:a").loop(8).to("mock:result"); Use expression to determine loop count from("direct:b").loop(header("loop")).to("mock:result"); Use expression to determine loop count from("direct:c").loop().xpath("/hello/@times").to("mock:result"); Using the Spring XML Extensions Pass loop count as an argument <route> <from uri="direct:a"/> <loop> <constant>8</constant> <to uri="mock:result"/> </loop> </route> Use expression to determine loop count <route> <from uri="direct:b"/> <loop> <header>loop</header> <to uri="mock:result"/> </loop> </route> For further examples of this pattern in use you could look at one of the junit test case Using copy modeAvailable as of Camel 2.8 Now suppose we send a message to "direct:start" endpoint containing the letter A. from("direct:start") // instruct loop to use copy mode, which mean it will use a copy of the input exchange // for each loop iteration, instead of keep using the same exchange all over .loop(3).copy() .transform(body().append("B")) .to("mock:loop") .end() .to("mock:result"); However if we do not enable copy mode then "mock:loop" will receive "AB", "ABB", "ABBB", etc. messages. from("direct:start") // by default loop will keep using the same exchange so on the 2nd and 3rd iteration its // the same exchange that was previous used that are being looped all over .loop(3) .transform(body().append("B")) .to("mock:loop") .end() .to("mock:result"); The equivalent example in XML DSL in copy mode is as follows: <route> <from uri="direct:start"/> <!-- enable copy mode for loop eip --> <loop copy="true"> <constant>3</constant> <transform> <simple>${body}B</simple> </transform> <to uri="mock:loop"/> </loop> <to uri="mock:result"/> </route> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message TransformationContent EnricherCamel supports the Content Enricher from the EIP patterns using a Message Translator, an arbitrary Processor in the routing logic or using the enrich DSL element to enrich the message.
Content enrichment using a Message Translator or a ProcessorUsing the Fluent Builders You can use Templating to consume a message from one destination, transform it with something like Velocity or XQuery and then send it on to another destination. For example using InOnly (one way messaging) from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"). to("activemq:Another.Queue"); If you want to use InOut (request-reply) semantics to process requests on the My.Queue queue on ActiveMQ with a template generated response, then sending responses back to the JMSReplyTo Destination you could use this: from("activemq:My.Queue"). to("velocity:com/acme/MyResponse.vm"); Here is a simple example using the DSL directly to transform the message body from("direct:start").setBody(body().append(" World!")).to("mock:result"); In this example we add our own Processor using explicit Java code from("direct:start").process(new Processor() { public void process(Exchange exchange) { Message in = exchange.getIn(); in.setBody(in.getBody(String.class) + " World!"); } }).to("mock:result"); Finally we can use Bean Integration to use any Java method on any bean to act as the transformer from("activemq:My.Queue"). beanRef("myBeanName", "myMethodName"). to("activemq:Another.Queue"); For further examples of this pattern in use you could look at one of the JUnit tests Using Spring XML <route> <from uri="activemq:Input"/> <bean ref="myBeanName" method="doTransform"/> <to uri="activemq:Output"/> </route> Content enrichment using the enrich DSL elementCamel comes with two flavors of content enricher in the DSL
enrich is using a Producer to obtain the additional data. It is usually used for Request Reply messaging, for instance to invoke an external web service. Enrich Options
Using the Fluent Builders AggregationStrategy aggregationStrategy = ... from("direct:start") .enrich("direct:resource", aggregationStrategy) .to("direct:result"); from("direct:resource") ... The content enricher (enrich) retrieves additional data from a resource endpoint in order to enrich an incoming message (contained in the original exchange). An aggregation strategy is used to combine the original exchange and the resource exchange. The first parameter of the AggregationStrategy.aggregate(Exchange, Exchange) method corresponds to the the original exchange, the second parameter the resource exchange. The results from the resource endpoint are stored in the resource exchange's out-message. Here's an example template for implementing an aggregation strategy: public class ExampleAggregationStrategy implements AggregationStrategy { public Exchange aggregate(Exchange original, Exchange resource) { Object originalBody = original.getIn().getBody(); Object resourceResponse = resource.getOut().getBody(); Object mergeResult = ... // combine original body and resource response if (original.getPattern().isOutCapable()) { original.getOut().setBody(mergeResult); } else { original.getIn().setBody(mergeResult); } return original; } } Using this template the original exchange can be of any pattern. The resource exchange created by the enricher is always an in-out exchange. Using Spring XML The same example in the Spring DSL <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <enrich uri="direct:resource" strategyRef="aggregationStrategy"/> <to uri="direct:result"/> </route> <route> <from uri="direct:resource"/> ... </route> </camelContext> <bean id="aggregationStrategy" class="..." /> Aggregation strategy is optionalThe aggregation strategy is optional. If you do not provide it Camel will by default just use the body obtained from the resource. from("direct:start") .enrich("direct:resource") .to("direct:result"); In the route above the message sent to the direct:result endpoint will contain the output from the direct:resource as we do not use any custom aggregation. And for Spring DSL just omit the strategyRef attribute: <route> <from uri="direct:start"/> <enrich uri="direct:resource"/> <to uri="direct:result"/> </route> Content enrichment using pollEnrichThe pollEnrich works just as the enrich however as it uses a Polling Consumer we have 3 methods when polling
PollEnrich Options
By default Camel will use the receiveNoWait. You can pass in a timeout value that determines which method to use
The timeout values is in millis.
ExampleIn this example we enrich the message by loading the content from the file named inbox/data.txt. from("direct:start") .pollEnrich("file:inbox?fileName=data.txt") .to("direct:result"); And in XML DSL you do: <route> <from uri="direct:start"/> <pollEnrich uri="file:inbox?fileName=data.txt"/> <to uri="direct:result"/> </route> If there is no file then the message is empty. We can use a timeout to either wait (potentially forever) until a file exists, or use a timeout to wait a certain period. For example to wait up to 5 seconds you can do: <route> <from uri="direct:start"/> <pollEnrich uri="file:inbox?fileName=data.txt" timeout="5000"/> <to uri="direct:result"/> </route> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Content FilterCamel supports the Content Filter from the EIP patterns using one of the following mechanisms in the routing logic to transform content from the inbound message.
A common way to filter messages is to use an Expression in the DSL like XQuery, SQL or one of the supported Scripting Languages. Using the Fluent Builders Here is a simple example using the DSL directly from("direct:start").setBody(body().append(" World!")).to("mock:result"); In this example we add our own Processor from("direct:start").process(new Processor() { public void process(Exchange exchange) { Message in = exchange.getIn(); in.setBody(in.getBody(String.class) + " World!"); } }).to("mock:result"); For further examples of this pattern in use you could look at one of the JUnit tests Using Spring XML <route> <from uri="activemq:Input"/> <bean ref="myBeanName" method="doTransform"/> <to uri="activemq:Output"/> </route> You can also use XPath to filter out part of the message you are interested in: <route> <from uri="activemq:Input"/> <setBody><xpath resultType="org.w3c.dom.Document">//foo:bar</xpath></setBody> <to uri="activemq:Output"/> </route> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Claim CheckThe Claim Check from the EIP patterns allows you to replace message content with a claim check (a unique key), which can be used to retrieve the message content at a later time. The message content is stored temporarily in a persistent store like a database or file system. This pattern is very useful when message content is very large (thus it would be expensive to send around) and not all components require all information. It can also be useful in situations where you cannot trust the information with an outside party; in this case, you can use the Claim Check to hide the sensitive portions of data.
Available in Camel 1.5. ExampleIn this example we want to replace a message body with a claim check, and restore the body at a later step. Using the Fluent Builders from("direct:start").to("bean:checkLuggage", "mock:testCheckpoint", "bean:dataEnricher", "mock:result"); Using the Spring XML Extensions <route> <from uri="direct:start"/> <pipeline> <to uri="bean:checkLuggage"/> <to uri="mock:testCheckpoint"/> <to uri="bean:dataEnricher"/> <to uri="mock:result"/> </pipeline> </route> The example route is pretty simple - its just a Pipeline. In a real application you would have some other steps where the mock:testCheckpoint endpoint is in the example. The message is first sent to the checkLuggage bean which looks like public static final class CheckLuggageBean { public void checkLuggage(Exchange exchange, @Body String body, @XPath("/order/@custId") String custId) { // store the message body into the data store, using the custId as the claim check dataStore.put(custId, body); // add the claim check as a header exchange.getIn().setHeader("claimCheck", custId); // remove the body from the message exchange.getIn().setBody(null); } } This bean stores the message body into the data store, using the custId as the claim check. In this example, we're just using a HashMap to store the message body; in a real application you would use a database or file system, etc. Next the claim check is added as a message header for use later. Finally we remove the body from the message and pass it down the pipeline. The next step in the pipeline is the mock:testCheckpoint endpoint which is just used to check that the message body is removed, claim check added, etc. To add the message body back into the message, we use the dataEnricher bean which looks like public static final class DataEnricherBean { public void addDataBackIn(Exchange exchange, @Header("claimCheck") String claimCheck) { // query the data store using the claim check as the key and add the data // back into the message body exchange.getIn().setBody(dataStore.get(claimCheck)); // remove the message data from the data store dataStore.remove(claimCheck); // remove the claim check header exchange.getIn().removeHeader("claimCheck"); } } This bean queries the data store using the claim check as the key and then adds the data back into the message. The message body is then removed from the data store and finally the claim check is removed. Now the message is back to what we started with! For full details, check the example source here: camel-core/src/test/java/org/apache/camel/processor/ClaimCheckTest.java Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. NormalizerCamel supports the Normalizer from the EIP patterns by using a Message Router in front of a number of Message Translator instances.
ExampleThis example shows a Message Normalizer that converts two types of XML messages into a common format. Messages in this common format are then filtered. Using the Fluent Builders // we need to normalize two types of incoming messages from("direct:start") .choice() .when().xpath("/employee").to("bean:normalizer?method=employeeToPerson") .when().xpath("/customer").to("bean:normalizer?method=customerToPerson") .end() .to("mock:result"); In this case we're using a Java bean as the normalizer. The class looks like this public class MyNormalizer { public void employeeToPerson(Exchange exchange, @XPath("/employee/name/text()") String name) { exchange.getOut().setBody(createPerson(name)); } public void customerToPerson(Exchange exchange, @XPath("/customer/@name") String name) { exchange.getOut().setBody(createPerson(name)); } private String createPerson(String name) { return "<person name=\"" + name + "\"/>"; } } Using the Spring XML Extensions The same example in the Spring DSL <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <choice> <when> <xpath>/employee</xpath> <to uri="bean:normalizer?method=employeeToPerson"/> </when> <when> <xpath>/customer</xpath> <to uri="bean:normalizer?method=customerToPerson"/> </when> </choice> <to uri="mock:result"/> </route> </camelContext> <bean id="normalizer" class="org.apache.camel.processor.MyNormalizer"/> See AlsoUsing This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. SortAvailable as of Camel 2.0 Sort can be used to sort a message. Imagine you consume text files and before processing each file you want to be sure the content is sorted. Sort will by default sort the body using a default comparator that handles numeric values or uses the string representation. You can provide your own comparator, and even an expression to return the value to be sorted. Sort requires the value returned from the expression evaluation is convertible to java.util.List as this is required by the JDK sort operation. Options
Using from Java DSLIn the route below it will read the file content and tokenize by line breaks so each line can be sorted.
from("file://inbox").sort(body().tokenize("\n")).to("bean:MyServiceBean.processLine");
You can pass in your own comparator as a 2nd argument:
from("file://inbox").sort(body().tokenize("\n"), new MyReverseComparator()).to("bean:MyServiceBean.processLine");
Using from Spring DSLIn the route below it will read the file content and tokenize by line breaks so each line can be sorted. Camel 2.7 or better <route> <from uri="file://inbox"/> <sort> <simple>body</simple> </sort> <beanRef ref="myServiceBean" method="processLine"/> </route> Camel 2.6 or older <route> <from uri="file://inbox"/> <sort> <expression> <simple>body</simple> </expression> </sort> <beanRef ref="myServiceBean" method="processLine"/> </route> And to use our own comparator we can refer to it as a spring bean: Camel 2.7 or better <route> <from uri="file://inbox"/> <sort comparatorRef="myReverseComparator"> <simple>body</simple> </sort> <beanRef ref="MyServiceBean" method="processLine"/> </route> <bean id="myReverseComparator" class="com.mycompany.MyReverseComparator"/> Camel 2.6 or older <route> <from uri="file://inbox"/> <sort comparatorRef="myReverseComparator"> <expression> <simple>body</simple> </expression> </sort> <beanRef ref="MyServiceBean" method="processLine"/> </route> <bean id="myReverseComparator" class="com.mycompany.MyReverseComparator"/> Besides <simple>, you can supply an expression using any language you like, so long as it returns a list. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Messaging EndpointsMessaging MapperCamel supports the Messaging Mapper from the EIP patterns by using either Message Translator pattern or the Type Converter module.
See also
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Event Driven ConsumerCamel supports the Event Driven Consumer from the EIP patterns. The default consumer model is event based (i.e. asynchronous) as this means that the Camel container can then manage pooling, threading and concurrency for you in a declarative manner.
The Event Driven Consumer is implemented by consumers implementing the Processor interface which is invoked by the Message Endpoint when a Message is available for processing. For more details see Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Polling ConsumerCamel supports implementing the Polling Consumer from the EIP patterns using the PollingConsumer interface which can be created via the Endpoint.createPollingConsumer() method.
So in your Java code you can do
Endpoint endpoint = context.getEndpoint("activemq:my.queue");
PollingConsumer consumer = endpoint.createPollingConsumer();
Exchange exchange = consumer.receive();
The ConsumerTemplate (discussed below) is also available. There are 3 main polling methods on PollingConsumer
ConsumerTemplateThe ConsumerTemplate is a template much like Spring's JmsTemplate or JdbcTemplate supporting the Polling Consumer EIP. With the template you can consume Exchanges from an Endpoint. The template supports the 3 operations above, but also including convenient methods for returning the body, etc consumeBody.
Exchange exchange = consumerTemplate.receive("activemq:my.queue");
Or to extract and get the body you can do: Object body = consumerTemplate.receiveBody("activemq:my.queue"); And you can provide the body type as a parameter and have it returned as the type: String body = consumerTemplate.receiveBody("activemq:my.queue", String.class); You get hold of a ConsumerTemplate from the CamelContext with the createConsumerTemplate operation: ConsumerTemplate consumer = context.createConsumerTemplate(); Using ConsumerTemplate with Spring DSLWith the Spring DSL we can declare the consumer in the CamelContext with the consumerTemplate tag, just like the ProducerTemplate. The example below illustrates this: <camelContext xmlns="http://camel.apache.org/schema/spring"> <!-- define a producer template --> <template id="producer"/> <!-- define a consumer template --> <consumerTemplate id="consumer"/> <route> <from uri="seda:foo"/> <to id="result" uri="mock:result"/> </route> </camelContext> Then we can get leverage Spring to inject the ConsumerTemplate in our java class. The code below is part of an unit test but it shows how the consumer and producer can work together. @ContextConfiguration public class SpringConsumerTemplateTest extends AbstractJUnit38SpringContextTests { @Autowired private ProducerTemplate producer; @Autowired private ConsumerTemplate consumer; @EndpointInject(ref = "result") private MockEndpoint mock; public void testConsumeTemplate() throws Exception { // we expect Hello World received in our mock endpoint mock.expectedBodiesReceived("Hello World"); // we use the producer template to send a message to the seda:start endpoint producer.sendBody("seda:start", "Hello World"); // we consume the body from seda:start String body = consumer.receiveBody("seda:start", String.class); assertEquals("Hello World", body); // and then we send the body again to seda:foo so it will be routed to the mock // endpoint so our unit test can complete producer.sendBody("seda:foo", body); // assert mock received the body mock.assertIsSatisfied(); } } Timer based polling consumerIn this sample we use a Timer to schedule a route to be started every 5th second and invoke our bean MyCoolBean where we implement the business logic for the Polling Consumer. Here we want to consume all messages from a JMS queue, process the message and send them to the next queue. First we setup our route as: MyCoolBean cool = new MyCoolBean(); cool.setProducer(template); cool.setConsumer(consumer); from("timer://foo?period=5000").bean(cool, "someBusinessLogic"); from("activemq:queue.foo").to("mock:result"); And then we have out logic in our bean: public static class MyCoolBean { private int count; private ConsumerTemplate consumer; private ProducerTemplate producer; public void setConsumer(ConsumerTemplate consumer) { this.consumer = consumer; } public void setProducer(ProducerTemplate producer) { this.producer = producer; } public void someBusinessLogic() { // loop to empty queue while (true) { // receive the message from the queue, wait at most 3 sec String msg = consumer.receiveBody("activemq:queue.inbox", 3000, String.class); if (msg == null) { // no more messages in queue break; } // do something with body msg = "Hello " + msg; // send it to the next queue producer.sendBodyAndHeader("activemq:queue.foo", msg, "number", count++); } } } Scheduled Poll ComponentsQuite a few inbound Camel endpoints use a scheduled poll pattern to receive messages and push them through the Camel processing routes. That is to say externally from the client the endpoint appears to use an Event Driven Consumer but internally a scheduled poll is used to monitor some kind of state or resource and then fire message exchanges. Since this a such a common pattern, polling components can extend the ScheduledPollConsumer base class which makes it simpler to implement this pattern. There is also the Quartz Component which provides scheduled delivery of messages using the Quartz enterprise scheduler. For more details see:
ScheduledPollConsumer OptionsThe ScheduledPollConsumer supports the following options:
About error handling and scheduled polling consumersScheduledPollConsumer is scheduled based and its run method is invoked periodically based on schedule settings. But errors can also occur when a poll is being executed. For instance if Camel should poll a file network, and this network resource is not available then a java.io.IOException could occur. As this error happens before any Exchange has been created and prepared for routing, then the regular Error handling in Camel does not apply. So what does the consumer do then? Well the exception is propagated back to the run method where its handled. Camel will by default log the exception at WARN level and then ignore it. At next schedule the error could have been resolved and thus being able to poll the endpoint successfully. Controlling the error handling using PollingConsumerPollStrategyorg.apache.camel.PollingConsumerPollStrategy is a pluggable strategy that you can configure on the ScheduledPollConsumer. The default implementation org.apache.camel.impl.DefaultPollingConsumerPollStrategy will log the caused exception at WARN level and then ignore this issue. The strategy interface provides the following 3 methods
In Camel 2.3 onwards the begin method returns a boolean which indicates whether or not to skipping polling. So you can implement your custom logic and return false if you do not want to poll this time. In Camel 2.6 onwards the commit method has an additional parameter containing the number of message that was actually polled. For example if there was no messages polled, the value would be zero, and you can react accordingly. The most interesting is the rollback as it allows you do handle the caused exception and decide what to do. For instance if we want to provide a retry feature to a scheduled consumer we can implement the PollingConsumerPollStrategy method and put the retry logic in the rollback method. Lets just retry up till 3 times:
public boolean rollback(Consumer consumer, Endpoint endpoint, int retryCounter, Exception e) throws Exception {
if (retryCounter < 3) {
// return true to tell Camel that it should retry the poll immediately
return true;
}
// okay we give up do not retry anymore
return false;
}
Notice that we are given the Consumer as a parameter. We could use this to restart the consumer as we can invoke stop and start:
// error occurred lets restart the consumer, that could maybe resolve the issue
consumer.stop();
consumer.start();
Notice: If you implement the begin operation make sure to avoid throwing exceptions as in such a case the poll operation is not invoked and Camel will invoke the rollback directly. Configuring an Endpoint to use PollingConsumerPollStrategyTo configure an Endpoint to use a custom PollingConsumerPollStrategy you use the option pollStrategy. For example in the file consumer below we want to use our custom strategy defined in the Registry with the bean id myPoll:
from("file://inbox/?pollStrategy=#myPoll").to("activemq:queue:inbox")
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. See AlsoCompeting ConsumersCamel supports the Competing Consumers from the EIP patterns using a few different components.
You can use the following components to implement competing consumers:-
Enabling Competing Consumers with JMSTo enable Competing Consumers you just need to set the concurrentConsumers property on the JMS endpoint. For example
from("jms:MyQueue?concurrentConsumers=5").bean(SomeBean.class);
or in Spring DSL <route> <from uri="jms:MyQueue?concurrentConsumers=5"/> <to uri="bean:someBean"/> </route> Or just run multiple JVMs of any ActiveMQ or JMS route Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Message DispatcherCamel supports the Message Dispatcher from the EIP patterns using various approaches.
You can use a component like JMS with selectors to implement a Selective Consumer as the Message Dispatcher implementation. Or you can use an Endpoint as the Message Dispatcher itself and then use a Content Based Router as the Message Dispatcher. See AlsoUsing This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Selective ConsumerThe Selective Consumer from the EIP patterns can be implemented in two ways
The first solution is to provide a Message Selector to the underlying URIs when creating your consumer. For example when using JMS you can specify a selector parameter so that the message broker will only deliver messages matching your criteria. The other approach is to use a Message Filter which is applied; then if the filter matches the message your consumer is invoked as shown in the following example Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .filter(header("foo").isEqualTo("bar")) .process(myProcessor); } }; Using the Spring XML Extensions <bean id="myProcessor" class="org.apache.camel.builder.MyProcessor"/> <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <filter> <xpath>$foo = 'bar'</xpath> <process ref="myProcessor"/> </filter> </route> </camelContext> Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Durable SubscriberCamel supports the Durable Subscriber from the EIP patterns using the JMS component which supports publish & subscribe using Topics with support for non-durable and durable subscribers.
Another alternative is to combine the Message Dispatcher or Content Based Router with File or JPA components for durable subscribers then something like SEDA for non-durable. Here is a simple example of creating durable subscribers to a JMS topic Using the Fluent Builders from("direct:start").to("activemq:topic:foo"); from("activemq:topic:foo?clientId=1&durableSubscriptionName=bar1").to("mock:result1"); from("activemq:topic:foo?clientId=2&durableSubscriptionName=bar2").to("mock:result2"); Using the Spring XML Extensions <route> <from uri="direct:start"/> <to uri="activemq:topic:foo"/> </route> <route> <from uri="activemq:topic:foo?clientId=1&durableSubscriptionName=bar1"/> <to uri="mock:result1"/> </route> <route> <from uri="activemq:topic:foo?clientId=2&durableSubscriptionName=bar2"/> <to uri="mock:result2"/> </route> Here is another example of JMS durable subscribers, but this time using virtual topics (recommended by AMQ over durable subscriptions) Using the Fluent Builders from("direct:start").to("activemq:topic:VirtualTopic.foo"); from("activemq:queue:Consumer.1.VirtualTopic.foo").to("mock:result1"); from("activemq:queue:Consumer.2.VirtualTopic.foo").to("mock:result2"); Using the Spring XML Extensions <route> <from uri="direct:start"/> <to uri="activemq:topic:VirtualTopic.foo"/> </route> <route> <from uri="activemq:queue:Consumer.1.VirtualTopic.foo"/> <to uri="mock:result1"/> </route> <route> <from uri="activemq:queue:Consumer.2.VirtualTopic.foo"/> <to uri="mock:result2"/> </route> See AlsoUsing This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Idempotent ConsumerThe Idempotent Consumer from the EIP patterns is used to filter out duplicate messages. This pattern is implemented using the IdempotentConsumer class. This uses an Expression to calculate a unique message ID string for a given message exchange; this ID can then be looked up in the IdempotentRepository to see if it has been seen before; if it has the message is consumed; if its not then the message is processed and the ID is added to the repository. The Idempotent Consumer essentially acts like a Message Filter to filter out duplicates. Camel will add the message id eagerly to the repository to detect duplication also for Exchanges currently in progress. Camel provides the following Idempotent Consumer implementations:
OptionsThe Idempotent Consumer has the following options:
Using the Fluent BuildersThe following example will use the header myMessageId to filter out duplicates RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .idempotentConsumer(header("myMessageId"), MemoryIdempotentRepository.memoryIdempotentRepository(200)) .to("seda:b"); } }; The above example will use an in-memory based MessageIdRepository which can easily run out of memory and doesn't work in a clustered environment. So you might prefer to use the JPA based implementation which uses a database to store the message IDs which have been processed from("direct:start").idempotentConsumer( header("messageId"), jpaMessageIdRepository(lookup(JpaTemplate.class), PROCESSOR_NAME) ).to("mock:result"); In the above example we are using the header messageId to filter out duplicates and using the collection myProcessorName to indicate the Message ID Repository to use. This name is important as you could process the same message by many different processors; so each may require its own logical Message ID Repository. For further examples of this pattern in use you could look at the junit test case Spring XML exampleThe following example will use the header myMessageId to filter out duplicates <!-- repository for the idempotent consumer --> <bean id="myRepo" class="org.apache.camel.processor.idempotent.MemoryIdempotentRepository"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <idempotentConsumer messageIdRepositoryRef="myRepo"> <!-- use the messageId header as key for identifying duplicate messages --> <header>messageId</header> <!-- if not a duplicate send it to this mock endpoint --> <to uri="mock:result"/> </idempotentConsumer> </route> </camelContext> How to handle duplicate messages in the routeAvailable as of Camel 2.8 You can now set the skipDuplicate option to false which instructs the idempotent consumer to route duplicate messages as well. However the duplicate message has been marked as duplicate by having a property on the Exchange set to true. We can leverage this fact by using a Content Based Router or Message Filter to detect this and handle duplicate messages. For example in the following example we use the Message Filter to send the message to a duplicate endpoint, and then stop continue routing that message. Filter duplicate messages from("direct:start") // instruct idempotent consumer to not skip duplicates as we will filter then our self .idempotentConsumer(header("messageId")).messageIdRepository(repo).skipDuplicate(false) .filter(property(Exchange.DUPLICATE_MESSAGE).isEqualTo(true)) // filter out duplicate messages by sending them to someplace else and then stop .to("mock:duplicate") .stop() .end() // and here we process only new messages (no duplicates) .to("mock:result"); The sample example in XML DSL would be: Filter duplicate messages <!-- idempotent repository, just use a memory based for testing --> <bean id="myRepo" class="org.apache.camel.processor.idempotent.MemoryIdempotentRepository"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <!-- we do not want to skip any duplicate messages --> <idempotentConsumer messageIdRepositoryRef="myRepo" skipDuplicate="false"> <!-- use the messageId header as key for identifying duplicate messages --> <header>messageId</header> <!-- we will to handle duplicate messages using a filter --> <filter> <!-- the filter will only react on duplicate messages, if this property is set on the Exchange --> <property>CamelDuplicateMessage</property> <!-- and send the message to this mock, due its part of an unit test --> <!-- but you can of course do anything as its part of the route --> <to uri="mock:duplicate"/> <!-- and then stop --> <stop/> </filter> <!-- here we route only new messages --> <to uri="mock:result"/> </idempotentConsumer> </route> </camelContext> How to handle duplicate message in a clustered environment with a data gridAvailable as of Camel 2.8 If you have running Camel in a clustered environment, a in memory idempotent repository doesn't work (see above). You can setup either a central database or use the idempotent consumer implementation based on the Hazelcast data grid. Hazelcast finds the nodes over multicast (which is default - configure Hazelcast for tcp-ip) and creates automatically a map based repository: HazelcastIdempotentRepository idempotentRepo = new HazelcastIdempotentRepository("myrepo"); from("direct:in").idempotentConsumer(header("messageId"), idempotentRepo).to("mock:out"); You have to define how long the repository should hold each message id (default is to delete it never). To avoid that you run out of memory you should create an eviction strategy based on the Hazelcast configuration. For additional information see camel-hazelcast. See this little tutorial, how setup such an idempotent repository on two cluster nodes using Apache Karaf. Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Transactional ClientCamel recommends supporting the Transactional Client from the EIP patterns using spring transactions.
Transaction Oriented Endpoints (Camel Toes) like JMS support using a transaction for both inbound and outbound message exchanges. Endpoints that support transactions will participate in the current transaction context that they are called from.
You should use the SpringRouteBuilder to setup the routes since you will need to setup the spring context with the TransactionTemplates that will define the transaction manager configuration and policies. For inbound endpoint to be transacted, they normally need to be configured to use a Spring PlatformTransactionManager. In the case of the JMS component, this can be done by looking it up in the spring context. You first define needed object in the spring configuration. <bean id="jmsTransactionManager" class="org.springframework.jms.connection.JmsTransactionManager"> <property name="connectionFactory" ref="jmsConnectionFactory" /> </bean> <bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="tcp://localhost:61616"/> </bean> Then you look them up and use them to create the JmsComponent. PlatformTransactionManager transactionManager = (PlatformTransactionManager) spring.getBean("jmsTransactionManager"); ConnectionFactory connectionFactory = (ConnectionFactory) spring.getBean("jmsConnectionFactory"); JmsComponent component = JmsComponent.jmsComponentTransacted(connectionFactory, transactionManager); component.getConfiguration().setConcurrentConsumers(1); ctx.addComponent("activemq", component); Transaction PoliciesOutbound endpoints will automatically enlist in the current transaction context. But what if you do not want your outbound endpoint to enlist in the same transaction as your inbound endpoint? The solution is to add a Transaction Policy to the processing route. You first have to define transaction policies that you will be using. The policies use a spring TransactionTemplate under the covers for declaring the transaction demarcation to use. So you will need to add something like the following to your spring xml: <bean id="PROPAGATION_REQUIRED" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="jmsTransactionManager"/> </bean> <bean id="PROPAGATION_REQUIRES_NEW" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="jmsTransactionManager"/> <property name="propagationBehaviorName" value="PROPAGATION_REQUIRES_NEW"/> </bean> Then in your SpringRouteBuilder, you just need to create new SpringTransactionPolicy objects for each of the templates. public void configure() { ... Policy requried = bean(SpringTransactionPolicy.class, "PROPAGATION_REQUIRED")); Policy requirenew = bean(SpringTransactionPolicy.class, "PROPAGATION_REQUIRES_NEW")); ... } Once created, you can use the Policy objects in your processing routes: // Send to bar in a new transaction from("activemq:queue:foo").policy(requirenew).to("activemq:queue:bar"); // Send to bar without a transaction. from("activemq:queue:foo").policy(notsupported ).to("activemq:queue:bar"); OSGi BlueprintIf you are using OSGi Blueprint then you most likely have to explicit declare a policy and refer to the policy from the transacted in the route. <bean id="required" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="jmsTransactionManager"/> <property name="propagationBehaviorName" value="PROPAGATION_REQUIRED"/> </bean> And then refer to "required" from the route: <route> <from uri="activemq:queue:foo"/> <transacted ref="required"/> <to uri="activemq:queue:bar"/> </route> Camel 1.x - Database SampleIn this sample we want to ensure that two endpoints is under transaction control. These two endpoints inserts data into a database. First of all we setup the usual spring stuff in its configuration file. Here we have defined a DataSource to the HSQLDB and a most importantly We use the required transaction policy that we define as the PROPOGATION_REQUIRED spring bean. And as last we have our book service bean that does the business logic <!-- datasource to the database --> <jdbc:embedded-database id="dataSource" type="DERBY"> <jdbc:script location="classpath:sql/init.sql" /> </jdbc:embedded-database> <!-- spring transaction manager --> <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- policy for required transaction used in our Camel routes --> <bean id="PROPAGATION_REQUIRED" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="txManager"/> <property name="propagationBehaviorName" value="PROPAGATION_REQUIRED"/> </bean> <!-- bean for book business logic --> <bean id="bookService" class="org.apache.camel.spring.interceptor.BookService"> <property name="dataSource" ref="dataSource"/> </bean> In our Camel route that is Java DSL based we setup the transactional policy, wrapped as a Policy. // Notice that we use the SpringRouteBuilder that has a few more features than // the standard RouteBuilder return new SpringRouteBuilder() { public void configure() throws Exception { // lookup the transaction policy SpringTransactionPolicy required = lookup("PROPAGATION_REQUIRED", SpringTransactionPolicy.class); // use this error handler instead of DeadLetterChannel that is the default // Notice: transactionErrorHandler is in SpringRouteBuilder if (isUseTransactionErrorHandler()) { // useTransactionErrorHandler is only used for unit testing to reuse code // for doing a 2nd test without this transaction error handler, so ignore // this. For spring based transaction, end users are encouraged to use the // transaction error handler instead of the default DeadLetterChannel. errorHandler(transactionErrorHandler(required)); } Then we are ready to define our Camel routes. We have two routes: 1 for success conditions, and 1 for a forced rollback condition. // set the required policy for this route from("direct:okay").policy(required). setBody(constant("Tiger in Action")).beanRef("bookService"). setBody(constant("Elephant in Action")).beanRef("bookService"); // set the required policy for this route from("direct:fail").policy(required). setBody(constant("Tiger in Action")).beanRef("bookService"). setBody(constant("Donkey in Action")).beanRef("bookService"); As its a unit test we need to setup the database and this is easily done with Spring JdbcTemplate Error formatting macro: snippet: java.lang.IndexOutOfBoundsException: Index: 20, Size: 20
And our core business service, the book service, will accept any books except the Donkeys. public class BookService { private SimpleJdbcTemplate jdbc; public BookService() { } public void setDataSource(DataSource ds) { jdbc = new SimpleJdbcTemplate(ds); } public void orderBook(String title) throws Exception { if (title.startsWith("Donkey")) { throw new IllegalArgumentException("We don't have Donkeys, only Camels"); } // create new local datasource to store in DB jdbc.update("insert into books (title) values (?)", title); } } Then we are ready to fire the tests. First to commit condition: public void testTransactionSuccess() throws Exception { template.sendBody("direct:okay", "Hello World"); int count = jdbc.queryForInt("select count(*) from books"); assertEquals("Number of books", 3, count); } And lastly the rollback condition since the 2nd book is a Donkey book: public void testTransactionRollback() throws Exception { try { template.sendBody("direct:fail", "Hello World"); } catch (RuntimeCamelException e) { // expected as we fail assertIsInstanceOf(RuntimeCamelException.class, e.getCause()); assertTrue(e.getCause().getCause() instanceof IllegalArgumentException); assertEquals("We don't have Donkeys, only Camels", e.getCause().getCause().getMessage()); } int count = jdbc.queryForInt("select count(*) from books"); assertEquals("Number of books", 1, count); } Camel 1.x - JMS SampleIn this sample we want to listen for messages on a queue and process the messages with our business logic java code and send them along. Since its based on a unit test the destination is a mock endpoint. This time we want to setup the camel context and routes using the Spring XML syntax. <!-- here we define our camel context --> <camel:camelContext id="myroutes"> <!-- and now our route using the XML syntax --> <camel:route errorHandlerRef="errorHandler"> <!-- 1: from the jms queue --> <camel:from uri="activemq:queue:okay"/> <!-- 2: setup the transactional boundaries to require a transaction --> <camel:transacted ref="PROPAGATION_REQUIRED"/> <!-- 3: call our business logic that is myProcessor --> <camel:process ref="myProcessor"/> <!-- 4: if success then send it to the mock --> <camel:to uri="mock:result"/> </camel:route> </camel:camelContext> <!-- this bean is our business logic --> <bean id="myProcessor" class="org.apache.camel.component.jms.tx.JMSTransactionalClientTest$MyProcessor"/> Since the rest is standard XML stuff its nothing fancy now for the reader: <!-- the transactional error handler --> <bean id="errorHandler" class="org.apache.camel.spring.spi.TransactionErrorHandlerBuilder"> <property name="springTransactionPolicy" ref="PROPAGATION_REQUIRED"/> </bean> <bean id="poolConnectionFactory" class="org.apache.activemq.pool.PooledConnectionFactory"> <property name="maxConnections" value="8"/> <property name="connectionFactory" ref="jmsConnectionFactory"/> </bean> <bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="vm://localhost?broker.persistent=false&broker.useJmx=false"/> </bean> <bean id="jmsTransactionManager" class="org.springframework.jms.connection.JmsTransactionManager"> <property name="connectionFactory" ref="poolConnectionFactory"/> </bean> <bean id="jmsConfig" class="org.apache.camel.component.jms.JmsConfiguration"> <property name="connectionFactory" ref="poolConnectionFactory"/> <property name="transactionManager" ref="jmsTransactionManager"/> <property name="transacted" value="true"/> <property name="concurrentConsumers" value="1"/> </bean> <bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="configuration" ref="jmsConfig"/> </bean> <bean id="PROPAGATION_REQUIRED" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="jmsTransactionManager"/> </bean> Our business logic is set to handle the incomming messages and fail the first two times. When its a success it responds with a Bye World message. public static class MyProcessor implements Processor { private int count; public void process(Exchange exchange) throws Exception { if (++count <= 2) { throw new IllegalArgumentException("Forced Exception number " + count + ", please retry"); } exchange.getIn().setBody("Bye World"); exchange.getIn().setHeader("count", count); } } And our unit test is tested with this java code. Notice that we expect the Bye World message to be delivered at the 3rd attempt. MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedMessageCount(1); mock.expectedBodiesReceived("Bye World"); // success at 3rd attempt mock.message(0).header("count").isEqualTo(3); template.sendBody("activemq:queue:okay", "Hello World"); mock.assertIsSatisfied(); Camel 1.x - Spring based configurationIn Camel 1.4 we have introduced the concept of configuration of the error handlers using spring XML configuration. The sample below demonstrates that you can configure transaction error handlers in Spring XML as spring beans. These can then be set as global, per route based or per policy based error handler. The latter has been demonstrated in the samples above. This sample is the database sample configured in Spring XML. Notice that we have defined two error handler, one per route. The first route uses the transaction error handler, and the 2nd uses no error handler at all. <!-- here we define our camel context --> <camel:camelContext id="myroutes"> <!-- first route with transaction error handler --> <!-- here we refer to our transaction error handler we define in this Spring XML file --> <!-- in this route the transactionErrorHandler is used --> <camel:route errorHandlerRef="transactionErrorHandler"> <!-- 1: from the jms queue --> <camel:from uri="activemq:queue:okay"/> <!-- 2: setup the transactional boundaries to require a transaction --> <camel:transacted ref="required"/> <!-- 3: call our business logic that is myProcessor --> <camel:process ref="myProcessor"/> <!-- 4: if success then send it to the mock --> <camel:to uri="mock:result"/> </camel:route> <!-- 2nd route with no error handling --> <!-- this route doens't use error handler, in fact the spring bean with id noErrorHandler --> <camel:route errorHandlerRef="noErrorHandler"> <camel:from uri="activemq:queue:bad"/> <camel:to uri="log:bad"/> </camel:route> </camel:camelContext> The following snippet is the Spring XML configuration to setup the error handlers in pure spring XML: <!-- camel policy we refer to in our route --> <bean id="required" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionTemplate" ref="PROPAGATION_REQUIRED"/> </bean> <!-- the standard spring transaction template for required --> <bean id="PROPAGATION_REQUIRED" class="org.springframework.transaction.support.TransactionTemplate"> <property name="transactionManager" ref="jmsTransactionManager"/> </bean> <!-- the transaction error handle we refer to from the route --> <bean id="transactionErrorHandler" class="org.apache.camel.spring.spi.TransactionErrorHandlerBuilder"> <property name="transactionTemplate" ref="PROPAGATION_REQUIRED"/> </bean> <!-- the no error handler --> <bean id="noErrorHandler" class="org.apache.camel.builder.NoErrorHandlerBuilder"/> DelayPolicy (@deprecated)DelayPolicy is a new policy introduced in Camel 1.5, to replaces the RedeliveryPolicy used in Camel 1.4. Notice the transactionErrorHandler can be configured with a DelayPolicy to set a fixed delay in millis between each redelivery attempt. Camel does this by sleeping the delay until transaction is marked for rollback and the caused exception is rethrown. This allows a simple redelivery interval that can be configured for development mode or light production to avoid a rapid redelivery strategy that can exhaust a system that constantly fails. The DelayPolicy is @deprecated and removed in Camel 2.0. All redelivery configuration should be configured on the back system. We strongly recommend that you configure the backing system for correct redelivery policy in your environment. Camel 2.0 - Database SampleIn this sample we want to ensure that two endpoints is under transaction control. These two endpoints inserts data into a database. First of all we setup the usual spring stuff in its configuration file. Here we have defined a DataSource to the HSQLDB and a most importantly As we use the new convention over configuration we do not need to configure a transaction policy bean, so we do not have any PROPAGATION_REQUIRED beans. <!-- this example uses JDBC so we define a data source --> <jdbc:embedded-database id="dataSource" type="DERBY"> <jdbc:script location="classpath:sql/init.sql" /> </jdbc:embedded-database> <!-- spring transaction manager --> <!-- this is the transaction manager Camel will use for transacted routes --> <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- bean for book business logic --> <bean id="bookService" class="org.apache.camel.spring.interceptor.BookService"> <property name="dataSource" ref="dataSource"/> </bean> Then we are ready to define our Camel routes. We have two routes: 1 for success conditions, and 1 for a forced rollback condition. <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:okay"/> <!-- we mark this route as transacted. Camel will lookup the spring transaction manager and use it by default. We can optimally pass in arguments to specify a policy to use that is configured with a spring transaction manager of choice. However Camel supports convention over configuration as we can just use the defaults out of the box and Camel that suites in most situations --> <transacted/> <setBody> <constant>Tiger in Action</constant> </setBody> <bean ref="bookService"/> <setBody> <constant>Elephant in Action</constant> </setBody> <bean ref="bookService"/> </route> <route> <from uri="direct:fail"/> <!-- we mark this route as transacted. See comments above. --> <transacted/> <setBody> <constant>Tiger in Action</constant> </setBody> <bean ref="bookService"/> <setBody> <constant>Donkey in Action</constant> </setBody> <bean ref="bookService"/> </route> </camelContext> That is all that is needed to configure a Camel route as being transacted. Just remember to use the transacted DSL. The rest is standard Spring XML to setup the transaction manager. Camel 2.0 - JMS SampleIn this sample we want to listen for messages on a queue and process the messages with our business logic java code and send them along. Since its based on a unit test the destination is a mock endpoint. First we configure the standard Spring XML to declare a JMS connection factory, a JMS transaction manager and our ActiveMQ component that we use in our routing. <!-- setup JMS connection factory --> <bean id="poolConnectionFactory" class="org.apache.activemq.pool.PooledConnectionFactory"> <property name="maxConnections" value="8"/> <property name="connectionFactory" ref="jmsConnectionFactory"/> </bean> <bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="vm://localhost?broker.persistent=false&broker.useJmx=false"/> </bean> <!-- setup spring jms TX manager --> <bean id="jmsTransactionManager" class="org.springframework.jms.connection.JmsTransactionManager"> <property name="connectionFactory" ref="poolConnectionFactory"/> </bean> <!-- define our activemq component --> <bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="connectionFactory" ref="poolConnectionFactory"/> <!-- define the jms consumer/producer as transacted --> <property name="transacted" value="true"/> <!-- setup the transaction manager to use --> <!-- if not provided then Camel will automatic use a JmsTransactionManager, however if you for instance use a JTA transaction manager then you must configure it --> <property name="transactionManager" ref="jmsTransactionManager"/> </bean> And then we configure our routes. Notice that all we have to do is mark the route as transacted using the transacted tag. <camelContext xmlns="http://camel.apache.org/schema/spring"> <!-- disable JMX during testing --> <jmxAgent id="agent" disabled="true"/> <route> <!-- 1: from the jms queue --> <from uri="activemq:queue:okay"/> <!-- 2: mark this route as transacted --> <transacted/> <!-- 3: call our business logic that is myProcessor --> <process ref="myProcessor"/> <!-- 4: if success then send it to the mock --> <to uri="mock:result"/> </route> </camelContext> <bean id="myProcessor" class="org.apache.camel.component.jms.tx.JMSTransactionalClientTest$MyProcessor"/>
Using multiple routes with different propagation behaviorsAvailable as of Camel 2.2
This is configured in the Spring XML file: <bean id="PROPAGATION_REQUIRED" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="txManager"/> <property name="propagationBehaviorName" value="PROPAGATION_REQUIRED"/> </bean> <bean id="PROPAGATION_REQUIRES_NEW" class="org.apache.camel.spring.spi.SpringTransactionPolicy"> <property name="transactionManager" ref="txManager"/> <property name="propagationBehaviorName" value="PROPAGATION_REQUIRES_NEW"/> </bean> Then in the routes you use transacted DSL to indicate which of these two propagations it uses. from("direct:mixed") // using required .transacted("PROPAGATION_REQUIRED") // all these steps will be okay .setBody(constant("Tiger in Action")).beanRef("bookService") .setBody(constant("Elephant in Action")).beanRef("bookService") // continue on route 2 .to("direct:mixed2"); from("direct:mixed2") // tell Camel that if this route fails then only rollback this last route // by using (rollback only *last*) .onException(Exception.class).markRollbackOnlyLast().end() // using a different propagation which is requires new .transacted("PROPAGATION_REQUIRES_NEW") // this step will be okay .setBody(constant("Lion in Action")).beanRef("bookService") // this step will fail with donkey .setBody(constant("Donkey in Action")).beanRef("bookService"); Notice how we have configured the onException in the 2nd route to indicate in case of any exceptions we should handle it and just rollback this transaction. See AlsoUsing This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Messaging GatewayCamel has several endpoint components that support the Messaging Gateway from the EIP patterns.
Components like Bean and CXF provide a a way to bind a Java interface to the message exchange. However you may want to read the Using CamelProxy documentation as a true Messaging Gateway EIP solution. See AlsoUsing This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Service ActivatorCamel has several endpoint components that support the Service Activator from the EIP patterns.
Components like Bean, CXF and Pojo provide a a way to bind the message exchange to a Java interface/service where the route defines the endpoints and wires it up to the bean. In addition you can use the Bean Integration to wire messages to a bean using annotation. Here is a simple example of using a Direct endpoint to create a messaging interface to a Pojo Bean service. Using the Fluent Builders from("direct:invokeMyService").to("bean:myService"); Using the Spring XML Extensions <route> <from uri="direct:invokeMyService"/> <to uri="bean:myService"/> </route> See AlsoUsing This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. System ManagementDetourThe Detour from the EIP patterns allows you to send messages through additional steps if a control condition is met. It can be useful for turning on extra validation, testing, debugging code when needed.
Available in Camel 1.5. ExampleIn this example we essentially have a route like from("direct:start").to("mock:result") with a conditional detour to the mock:detour endpoint in the middle of the route.. from("direct:start").choice() .when().method("controlBean", "isDetour").to("mock:detour").end() .to("mock:result"); Using the Spring XML Extensions <route> <from uri="direct:start"/> <choice> <when> <method bean="controlBean" method="isDetour"/> <to uri="mock:detour"/> </when> </choice> <to uri="mock:result"/> </split> </route> whether the detour is turned on or off is decided by the ControlBean. So, when the detour is on the message is routed to mock:detour and then mock:result. When the detour is off, the message is routed to mock:result. For full details, check the example source here: camel-core/src/test/java/org/apache/camel/processor/DetourTest.java Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Wire TapWire Tap (from the EIP patterns) allows you to route messages to a separate location while they are forwarded to the ultimate destination.
Options
WireTap thread poolThe Wire Tap uses a thread pool to process the tapped messages. This thread pool will by default use the settings detailed at Threading Model. In particular, when the pool is exhausted (with all threads utilized), further wiretaps will be executed synchronously by the calling thread. To remedy this, you can configure an explicit thread pool on the Wire Tap having either a different rejection policy, a larger worker queue, or more worker threads. WireTap nodeAvailable as of Camel 2.0 In Camel 2.0 we have introduced a new wireTap node to facilitate wiretaps. Camel will copy the original Exchange and set its Exchange Pattern to InOnly, as we want the tapped Exchange to be sent in a fire and forget style. The tapped Exchange is then sent in a separate thread so it can run in parallel with the original. We have extended wireTap to support two flavors when tapping an Exchange:
Sending a copy (traditional wiretap)Using the Fluent Builders from("direct:start") .to("log:foo") .wireTap("direct:tap") .to("mock:result"); Using the Spring XML Extensions <route> <from uri="direct:start"/> <to uri="log:foo"/> <wireTap uri="direct:tap"/> <to uri="mock:result"/> </route> Sending a new ExchangeUsing the Fluent Builders From Camel 2.3 onwards the Expression or Processor is pre-populated with a copy of the original Exchange, which allows you to access the original message when you prepare a new Exchange to be sent. You can use the copy option (enabled by default) to indicate whether you want this. If you set copy=false, then it works as in Camel 2.2 or older where the Exchange will be empty. Below is the processor variation. This example is from Camel 2.3, where we disable copy by passing in false to create a new, empty Exchange. from("direct:start") .wireTap("direct:foo", false, new Processor() { public void process(Exchange exchange) throws Exception { exchange.getIn().setBody("Bye World"); exchange.getIn().setHeader("foo", "bar"); } }).to("mock:result"); from("direct:foo").to("mock:foo"); Here is the Expression variation. This example is from Camel 2.3, where we disable copy by passing in false to create a new, empty Exchange. from("direct:start") .wireTap("direct:foo", false, constant("Bye World")) .to("mock:result"); from("direct:foo").to("mock:foo"); Using the Spring XML Extensions <route> <from uri="direct:start2"/> <wireTap uri="direct:foo" processorRef="myProcessor"/> <to uri="mock:result"/> </route> Here is the Expression variation, where the expression is defined in the body tag: <route> <from uri="direct:start"/> <wireTap uri="direct:foo"> <body><constant>Bye World</constant></body> </wireTap> <to uri="mock:result"/> </route> This variation accesses the body of the original message and creates a new Exchange based on the Expression. It will create a new Exchange and have the body contain "Bye ORIGINAL BODY MESSAGE HERE" <route> <from uri="direct:start"/> <wireTap uri="direct:foo"> <body><simple>Bye ${body}</simple></body> </wireTap> <to uri="mock:result"/> </route> Camel 1.xThe following example shows how to route a request from an input queue:a endpoint to the wire tap location queue:tap before it is received by queue:b Using the Fluent Builders RouteBuilder builder = new RouteBuilder() { public void configure() { errorHandler(deadLetterChannel("mock:error")); from("seda:a") .multicast().to("seda:tap", "seda:b"); } }; Using the Spring XML Extensions <camelContext errorHandlerRef="errorHandler" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="seda:a"/> <multicast> <to uri="seda:tap"/> <to uri="seda:b"/> </multicast> </route> </camelContext> Further ExampleFor another example of this pattern, refer to the wire tap test case. Sending a new Exchange and set headers in DSLAvailable as of Camel 2.8 If you send a new message using Wire Tap, then you could only set the message body using an Expression from the DSL. If you also need to set headers, you would have to use a Processor. In Camel 2.8 onwards, you can now set headers as well in the DSL. The following example sends a new message which has
Java DSLfrom("direct:start") // tap a new message and send it to direct:tap // the new message should be Bye World with 2 headers .wireTap("direct:tap") // create the new tap message body and headers .newExchangeBody(constant("Bye World")) .newExchangeHeader("id", constant(123)) .newExchangeHeader("date", simple("${date:now:yyyyMMdd}")) .end() // here we continue routing the original messages .to("mock:result"); // this is the tapped route from("direct:tap") .to("mock:tap"); XML DSLThe XML DSL is slightly different than Java DSL in how you configure the message body and headers using <body> and <setHeader>: <route> <from uri="direct:start"/> <!-- tap a new message and send it to direct:tap --> <!-- the new message should be Bye World with 2 headers --> <wireTap uri="direct:tap"> <!-- create the new tap message body and headers --> <body><constant>Bye World</constant></body> <setHeader headerName="id"><constant>123</constant></setHeader> <setHeader headerName="date"><simple>${date:now:yyyyMMdd}</simple></setHeader> </wireTap> <!-- here we continue routing the original message --> <to uri="mock:result"/> </route> Using onPrepare to execute custom logic when preparing messagesAvailable as of Camel 2.8 See details at Multicast Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. LogHow can I log processing a Message? Camel provides many ways to log processing a message. Here is just some examples:
Using log DSLAnd in Camel 2.2 you can use the log DSL which allows you to use Simple language to construct a dynamic message which gets logged. from("direct:start").log("Processing ${id}").to("bean:foo"); Which will construct a String message at runtime using the Simple language. The log message will by logged at INFO level using the route id as the log name. By default a route is named route-1, route-2 etc. But you can use the routeId("myCoolRoute") to set a route name of choice.
The log DSL have overloaded methods to set the logging level and/or name as well. from("direct:start").log(LoggingLevel.DEBUG, "Processing ${id}").to("bean:foo"); For example you can use this to log the file name being processed if you consume files.
from("file://target/files").log(LoggingLevel.DEBUG, "Processing file ${file:name}").to("bean:foo");
Using log DSL from SpringIn Spring DSL its also easy to use log DSL as shown below:
<route id="foo">
<from uri="direct:foo"/>
<log message="Got ${body}"/>
<to uri="mock:foo"/>
</route>
The log tag has attributes to set the message, loggingLevel and logName. For example:
<route id="baz">
<from uri="direct:baz"/>
<log message="Me Got ${body}" loggingLevel="FATAL" logName="cool"/>
<to uri="mock:baz"/>
</route>
Using slf4j MarkerAvailable as of Camel 2.9 You can specify a marker name in the DSL
<route id="baz">
<from uri="direct:baz"/>
<log message="Me Got ${body}" loggingLevel="FATAL" logName="cool" marker="myMarker"/>
<to uri="mock:baz"/>
</route>
Using This PatternIf you would like to use this EIP Pattern then please read the Getting Started, you may also find the Architecture useful particularly the description of Endpoint and URIs. Then you could try out some of the Examples first before trying this pattern out. Component AppendixThere now follows the documentation on each Camel component. ActiveMQ ComponentThe ActiveMQ component allows messages to be sent to a JMS Queue or Topic or messages to be consumed from a JMS Queue or Topic using Apache ActiveMQ. This component is based on JMS Component and uses Spring's JMS support for declarative transactions, using Spring's JmsTemplate for sending and a MessageListenerContainer for consuming. All the options from the JMS component also applies for this component. To use this component make sure you have the activemq.jar or activemq-core.jar on your classpath along with any Camel dependencies such as camel-core.jar, camel-spring.jar and camel-jms.jar.
URI formatactivemq:[queue:|topic:]destinationName Where destinationName is an ActiveMQ queue or topic name. By default, the destinationName is interpreted as a queue name. For example, to connect to the queue, FOO.BAR, use: activemq:FOO.BAR You can include the optional queue: prefix, if you prefer: activemq:queue:FOO.BAR To connect to a topic, you must include the topic: prefix. For example, to connect to the topic, Stocks.Prices, use: activemq:topic:Stocks.Prices OptionsSee Options on the JMS component as all these options also apply for this component. Configuring the Connection FactoryThis test case shows how to add an ActiveMQComponent to the CamelContext using the activeMQComponent() method while specifying the brokerURL used to connect to ActiveMQ. camelContext.addComponent("activemq", activeMQComponent("vm://localhost?broker.persistent=false")); Configuring the Connection Factory using Spring XMLYou can configure the ActiveMQ broker URL on the ActiveMQComponent as follows <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camelContext xmlns="http://camel.apache.org/schema/spring"> </camelContext> <bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="brokerURL" value="tcp://somehost:61616"/> </bean> </beans> Using connection poolingWhen sending to an ActiveMQ broker using Camel it's recommended to use a pooled connection factory to efficiently handle pooling of JMS connections, sessions and producers. This is documented on the ActiveMQ Spring Support page. You can grab ActiveMQ's org.apache.activemq.pool.PooledConnectionFactory with Maven: <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-pool</artifactId> <version>5.3.2</version> </dependency> And then setup the activemq Camel component as follows: <bean id="jmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="tcp://localhost:61616" /> </bean> <bean id="pooledConnectionFactory" class="org.apache.activemq.pool.PooledConnectionFactory"> <property name="maxConnections" value="8" /> <property name="maximumActive" value="500" /> <property name="connectionFactory" ref="jmsConnectionFactory" /> </bean> <bean id="jmsConfig" class="org.apache.camel.component.jms.JmsConfiguration"> <property name="connectionFactory" ref="pooledConnectionFactory"/> <property name="transacted" value="false"/> <property name="concurrentConsumers" value="10"/> </bean> <bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="configuration" ref="jmsConfig"/> </bean> Invoking MessageListener POJOs in a Camel routeThe ActiveMQ component also provides a helper Type Converter from a JMS MessageListener to a Processor. This means that the Bean component is capable of invoking any JMS MessageListener bean directly inside any route. So for example you can create a MessageListener in JMS like this: public class MyListener implements MessageListener { public void onMessage(Message jmsMessage) { // ... } } Then use it in your Camel route as follows
from("file://foo/bar").
bean(MyListener.class);
That is, you can reuse any of the Camel Components and easily integrate them into your JMS MessageListener POJO! Using ActiveMQ Destination OptionsAvailable as of ActiveMQ 5.6 You can configure the Destination Options in the endpoint uri, using the "destination." prefix. For example to mark a consumer as exclusive, and set its prefetch size to 50, you can do as follows: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="file://src/test/data?noop=true"/> <to uri="activemq:queue:foo"/> </route> <route> <!-- use consumer.exclusive ActiveMQ destination option, notice we have to prefix with destination. --> <from uri="activemq:foo?destination.consumer.exclusive=true&destination.consumer.prefetchSize=50"/> <to uri="mock:results"/> </route> </camelContext> Consuming Advisory MessagesActiveMQ can generate Advisory messages which are put in topics that you can consume. Such messages can help you send alerts in case you detect slow consumers or to build statistics (number of messages/produced per day, etc.) The following Spring DSL example shows you how to read messages from a topic. The below route starts by reading the topic ActiveMQ.Advisory.Connection. To watch another topic, simply change the name according to the name provided in ActiveMQ Advisory Messages documentation. The parameter mapJmsMessage=false allows for converting the org.apache.activemq.command.ActiveMqMessage object from the jms queue. Next, the body received is converted into a String for the purposes of this example and a carriage return is added. Finally, the string is added to a file <route> <from uri="activemq:topic:ActiveMQ.Advisory.Connection?mapJmsMessage=false" /> <convertBodyTo type="java.lang.String"/> <transform> <simple>${in.body} </simple> </transform> <to uri="file://data/activemq/?fileExist=Append&fileName=advisoryConnection-${date:now:yyyyMMdd}.txt" /> </route> If you consume a message on a queue, you should see the following files under the data/activemq folder : advisoryConnection-20100312.txt and containing string:
ActiveMQMessage {commandId = 0, responseRequired = false,
messageId = ID:dell-charles-3258-1268399815140
-1:0:0:0:221, originalDestination = null, originalTransactionId = null,
producerId = ID:dell-charles-3258-1268399815140-1:0:0:0,
destination = topic://ActiveMQ.Advisory.Connection, transactionId = null,
expiration = 0, timestamp = 0, arrival = 0, brokerInTime = 1268403383468,
brokerOutTime = 1268403383468, correlationId = null, replyTo = null,
persistent = false, type = Advisory, priority = 0, groupID = null, groupSequence = 0,
targetConsumerId = null, compressed = false, userID = null, content = null,
marshalledProperties = org.apache.activemq.util.ByteSequence@17e2705,
dataStructure = ConnectionInfo {commandId = 1, responseRequired = true,
connectionId = ID:dell-charles-3258-1268399815140-2:50,
clientId = ID:dell-charles-3258-1268399815140-14:0, userName = , password = *****,
brokerPath = null, brokerMasterConnector = false, manageable = true,
clientMaster = true}, redeliveryCounter = 0, size = 0, properties =
{originBrokerName=master, originBrokerId=ID:dell-charles-3258-1268399815140-0:0,
originBrokerURL=vm://master}, readOnlyProperties = true, readOnlyBody = true,
droppable = false}
Getting Component JARYou will need these dependencies
camel-jmsYou must have the camel-jms as dependency as ActiveMQ is an extension to the JMS component. <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jms</artifactId> <version>1.6.0</version> </dependency> The ActiveMQ Camel component is released with the ActiveMQ project itself. ActiveMQ 5.2 or later<dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-camel</artifactId> <version>5.2.0</version> </dependency> ActiveMQ 5.1.0For 5.1.0 its in the activemq-core library <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-core</artifactId> <version>5.1.0</version> </dependency> Alternatively you can download the component jar directly from the Maven repository: ActiveMQ 4.xFor this version you must use the JMS component instead. Please be careful to use a pooling connection factory as described in the JmsTemplate Gotchas See AlsoActiveMQ Journal ComponentThe ActiveMQ Journal Component allows messages to be stored in a rolling log file and then consumed from that log file. The journal aggregates and batches up concurrent writes so that the overhead of writing and waiting for the disk sync is relatively constant regardless of how many concurrent writes are being done. Therefore, this component supports and encourages you to use multiple concurrent producers to the same journal endpoint. Each journal endpoint uses a different log file and therefore write batching (and the associated performance boost) does not occur between multiple endpoints. This component only supports one active consumer on the endpoint. After the message is processed by the consumer's processor, the log file is marked and only subsequent messages in the log file will get delivered to consumers. URI formatactivemq.journal:directoryName[?options] So for example, to send to the journal located in the /tmp/data directory you would use the following URI: activemq.journal:/tmp/data Options
You can append query options to the URI in the following format, ?option=value&option=value&... Expected Exchange Data TypesThe consumer of a Journal endpoint generates DefaultExchange objects with the in message :
The producer to a Journal endpoint expects an Exchange with an In message where the body can be converted to a ByteSequence or a byte[]. See AlsoAMQPThe amqp: component supports the AMQP protocol using the Client API of the Qpid project. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-amqp</artifactId> <version>${camel.version}</version> <!-- use the same version as your Camel core version --> </dependency> URI formatamqp:[queue:|topic:]destinationName[?options] You can specify all of the various configuration options of the JMS component after the destination name. See AlsoSQS ComponentAvailable as of Camel 2.6 The sqs component supports sending and receiving messages to Amazon's SQS service.
URI Format
aws-sqs://queue-name[?options]
The queue will be created if they don't already exists. URI Options
Batch ConsumerThis component implements the Batch Consumer. This allows you for instance to know how many messages exists in this batch and for instance let the Aggregator aggregate this number of messages. UsageMessage headers set by the SQS producer
Message headers set by the SQS consumer
Advanced AmazonSQSClient configurationIf your Camel Application is running behind a firewall or if you need to have more control over the AmazonSQSClient configuration, you can create your own instance: AWSCredentials awsCredentials = new BasicAWSCredentials("myAccessKey", "mySecretKey"); ClientConfiguration clientConfiguration = new ClientConfiguration(); clientConfiguration.setProxyHost("http://myProxyHost"); clientConfiguration.setProxyPort(8080); AmazonSQSClient client = new AmazonSQSClient(awsCredentials, clientConfiguration); and refer to it in your Camel aws-sqs component configuration: from("aws-sqs://MyQueue?amazonSQSClient=#amazonSQSClient&delay=5000&maxMessagesPerPoll=5") .to("mock:result"); DependenciesMaven users will need to add the following dependency to their pom.xml. pom.xml <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-aws</artifactId> <version>${camel-version}</version> </dependency> where ${camel-version} must be replaced by the actual version of Camel (2.6 or higher). See AlsoAtom ComponentThe atom: component is used for polling Atom feeds. Camel will poll the feed every 60 seconds by default. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-atom</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
atom://atomUri[?options]
Where atomUri is the URI to the Atom feed to poll. Options
You can append query options to the URI in the following format, ?option=value&option=value&... Exchange data formatCamel will set the In body on the returned Exchange with the entries. Depending on the splitEntries flag Camel will either return one Entry or a List<Entry>.
Camel can set the Feed object on the In header (see feedHeader option to disable this): Message HeadersCamel atom uses these headers.
SamplesIn this sample we poll James Strachan's blog.
from("atom://http://macstrac.blogspot.com/feeds/posts/default").to("seda:feeds");
In this sample we want to filter only good blogs we like to a SEDA queue. The sample also shows how to setup Camel standalone, not running in any Container or using Spring. // This is the CamelContext that is the heart of Camel private CamelContext context; protected CamelContext createCamelContext() throws Exception { // First we register a blog service in our bean registry SimpleRegistry registry = new SimpleRegistry(); registry.put("blogService", new BlogService()); // Then we create the camel context with our bean registry context = new DefaultCamelContext(registry); // Then we add all the routes we need using the route builder DSL syntax context.addRoutes(createMyRoutes()); return context; } /** * This is the route builder where we create our routes using the Camel DSL */ protected RouteBuilder createMyRoutes() throws Exception { return new RouteBuilder() { public void configure() throws Exception { // We pool the atom feeds from the source for further processing in the seda queue // we set the delay to 1 second for each pool as this is a unit test also and we can // not wait the default poll interval of 60 seconds. // Using splitEntries=true will during polling only fetch one Atom Entry at any given time. // As the feed.atom file contains 7 entries, using this will require 7 polls to fetch the entire // content. When Camel have reach the end of entries it will refresh the atom feed from URI source // and restart - but as Camel by default uses the UpdatedDateFilter it will only deliver new // blog entries to "seda:feeds". So only when James Straham updates his blog with a new entry // Camel will create an exchange for the seda:feeds. from("atom:file:src/test/data/feed.atom?splitEntries=true&consumer.delay=1000").to("seda:feeds"); // From the feeds we filter each blot entry by using our blog service class from("seda:feeds").filter().method("blogService", "isGoodBlog").to("seda:goodBlogs"); // And the good blogs is moved to a mock queue as this sample is also used for unit testing // this is one of the strengths in Camel that you can also use the mock endpoint for your // unit tests from("seda:goodBlogs").to("mock:result"); } }; } /** * This is the actual junit test method that does the assertion that our routes is working as expected */ @Test public void testFiltering() throws Exception { // create and start Camel context = createCamelContext(); context.start(); // Get the mock endpoint MockEndpoint mock = context.getEndpoint("mock:result", MockEndpoint.class); // There should be at least two good blog entries from the feed mock.expectedMinimumMessageCount(2); // Asserts that the above expectations is true, will throw assertions exception if it failed // Camel will default wait max 20 seconds for the assertions to be true, if the conditions // is true sooner Camel will continue mock.assertIsSatisfied(); // stop Camel after use context.stop(); } /** * Services for blogs */ public class BlogService { /** * Tests the blogs if its a good blog entry or not */ public boolean isGoodBlog(Exchange exchange) { Entry entry = exchange.getIn().getBody(Entry.class); String title = entry.getTitle(); // We like blogs about Camel boolean good = title.toLowerCase().contains("camel"); return good; } } See AlsoBean ComponentThe bean: component binds beans to Camel message exchanges. URI formatbean:beanID[?options] Where beanID can be any string which is used to look up the bean in the Registry Options
You can append query options to the URI in the following format, ?option=value&option=value&... UsingThe object instance that is used to consume messages must be explicitly registered with the Registry. For example, if you are using Spring you must define the bean in the Spring configuration, spring.xml; or if you don't use Spring, by registering the bean in JNDI. // lets populate the context with the services we need // note that we could just use a spring.xml file to avoid this step JndiContext context = new JndiContext(); context.bind("bye", new SayService("Good Bye!")); CamelContext camelContext = new DefaultCamelContext(context); Once an endpoint has been registered, you can build Camel routes that use it to process exchanges. // lets add simple route camelContext.addRoutes(new RouteBuilder() { public void configure() { from("direct:hello").to("bean:bye"); } }); A bean: endpoint cannot be defined as the input to the route; i.e. you cannot consume from it, you can only route from some inbound message Endpoint to the bean endpoint as output. So consider using a direct: or queue: endpoint as the input. You can use the createProxy() methods on ProxyHelper to create a proxy that will generate BeanExchanges and send them to any endpoint: Endpoint endpoint = camelContext.getEndpoint("direct:hello"); ISay proxy = ProxyHelper.createProxy(endpoint, ISay.class); String rc = proxy.say(); assertEquals("Good Bye!", rc); And the same route using Spring DSL: <route> <from uri="direct:hello"> <to uri="bean:bye"/> </route> Bean as endpointCamel also supports invoking Bean as an Endpoint. In the route below: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <to uri="myBean"/> <to uri="mock:results"/> </route> </camelContext> <bean id="myBean" class="org.apache.camel.spring.bind.ExampleBean"/> What happens is that when the exchange is routed to the myBean Camel will use the Bean Binding to invoke the bean. public class ExampleBean { public String sayHello(String name) { return "Hello " + name + "!"; } } Camel will use Bean Binding to invoke the sayHello method, by converting the Exchange's In body to the String type and storing the output of the method on the Exchange Out body. Bean BindingHow bean methods to be invoked are chosen (if they are not specified explicitly through the method parameter) and how parameter values are constructed from the Message are all defined by the Bean Binding mechanism which is used throughout all of the various Bean Integration mechanisms in Camel. See Also
Bean Validation ComponentAvailable as of Camel 2.3 The Validation component performs bean validation of the message body using the Java Bean Validation API (JSR 303). Camel uses the reference implementation, which is Hibernate Validator. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-bean-validator</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatbean-validator:something[?options] or
bean-validator://something[?options]
Where something must be present to provide a valid url URI Options
ServiceMix4/OSGi Deployment.The bean-validator when deployed in an OSGi environment requires a little help to accommodate the resource loading specified in JSR303, this was fixed in Servicemix-Specs 1.6-SNAPSHOT. ExampleAssumed we have a java bean with the following annotations Car.java public class Car { @NotNull private String manufacturer; @NotNull @Size(min = 5, max = 14, groups = OptionalChecks.class) private String licensePlate; // getter and setter } and an interface definition for our custom validation group OptionalChecks.java public interface OptionalChecks { } with the following Camel route, only the @NotNull constraints on the attributes manufacturer and licensePlate will be validated (Camel uses the default group javax.validation.groups.Default). from("direct:start") .to("bean-validator://x") .to("mock:end") If you want to check the constraints from the group OptionalChecks, you have to define the route like this from("direct:start") .to("bean-validator://x?group=OptionalChecks") .to("mock:end") If you want to check the constraints from both groups, you have to define a new interface first AllChecks.java
@GroupSequence({Default.class, OptionalChecks.class})
public interface AllChecks {
}
and then your route definition should looks like this from("direct:start") .to("bean-validator://x?group=AllChecks") .to("mock:end") And if you have to provide your own message interpolator, traversable resolver and constraint validator factory, you have to write a route like this <bean id="myMessageInterpolator" class="my.ConstraintValidatorFactory" /> <bean id="myTraversableResolver" class="my.TraversableResolver" /> <bean id="myConstraintValidatorFactory" class="my.ConstraintValidatorFactory" /> from("direct:start") .to("bean-validator://x?group=AllChecks&messageInterpolator=#myMessageInterpolator &traversableResolver=#myTraversableResolver&constraintValidatorFactory=#myConstraintValidatorFactory") .to("mock:end") It's also possible to describe your constraints as XML and not as Java annotations. In this case, you have to provide the file META-INF/validation.xml which could looks like this validation.xml <?xml version="1.0" encoding="UTF-8"?> <validation-config xmlns="http://jboss.org/xml/ns/javax/validation/configuration" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jboss.org/xml/ns/javax/validation/configuration"> <default-provider>org.hibernate.validator.HibernateValidator</default-provider> <message-interpolator>org.hibernate.validator.engine.ResourceBundleMessageInterpolator</message-interpolator> <traversable-resolver>org.hibernate.validator.engine.resolver.DefaultTraversableResolver</traversable-resolver> <constraint-validator-factory>org.hibernate.validator.engine.ConstraintValidatorFactoryImpl</constraint-validator-factory> <constraint-mapping>/constraints-car.xml</constraint-mapping> </validation-config> and the constraints-car.xml file constraints-car.xml <?xml version="1.0" encoding="UTF-8"?> <constraint-mappings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jboss.org/xml/ns/javax/validation/mapping validation-mapping-1.0.xsd" xmlns="http://jboss.org/xml/ns/javax/validation/mapping"> <default-package>org.apache.camel.component.bean.validator</default-package> <bean class="CarWithoutAnnotations" ignore-annotations="true"> <field name="manufacturer"> <constraint annotation="javax.validation.constraints.NotNull" /> </field> <field name="licensePlate"> <constraint annotation="javax.validation.constraints.NotNull" /> <constraint annotation="javax.validation.constraints.Size"> <groups> <value>org.apache.camel.component.bean.validator.OptionalChecks</value> </groups> <element name="min">5</element> <element name="max">14</element> </constraint> </field> </bean> </constraint-mappings> See AlsoBrowse ComponentAvailable as of Camel 2.0 The Browse component provides a simple BrowsableEndpoint which can be useful for testing, visualisation tools or debugging. The exchanges sent to the endpoint are all available to be browsed. URI formatbrowse:someName Where someName can be any string to uniquely identify the endpoint. SampleIn the route below, we insert a browse: component to be able to browse the Exchanges that are passing through: from("activemq:order.in").to("browse:orderReceived").to("bean:processOrder"); We can now inspect the received exchanges from within the Java code:
private CamelContext context;
public void inspectRecievedOrders() {
BrowsableEndpoint browse = context.getEndpoint("browse:orderReceived", BrowsableEndpoint.class);
List<Exchange> exchanges = browse.getExchanges();
...
// then we can inspect the list of received exchanges from Java
for (Exchange exchange : exchanges) {
String payload = exchange.getIn().getBody();
...
}
}
See AlsoCache ComponentAvailable as of Camel 2.1 The cache component enables you to perform caching operations using EHCache as the Cache Implementation. The cache itself is created on demand or if a cache of that name already exists then it is simply utilized with its original settings. This component supports producer and event based consumer endpoints. The Cache consumer is an event based consumer and can be used to listen and respond to specific cache activities. If you need to perform selections from a pre-existing cache, used the processors defined for the cache component. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-cache</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
cache://cacheName[?options]
You can append query options to the URI in the following format, ?option=value&option=#beanRef&... Options
Sending/Receiving Messages to/from the cacheMessage Headers up to Camel 2.7
Message Headers Camel 2.8+
Cache ProducerSending data to the cache involves the ability to direct payloads in exchanges to be stored in a pre-existing or created-on-demand cache. The mechanics of doing this involve
Cache ConsumerReceiving data from the cache involves the ability of the CacheConsumer to listen on a pre-existing or created-on-demand Cache using an event Listener and receive automatic notifications when any cache activity take place (i.e CamelCacheGet/CamelCacheUpdate/CamelCacheDelete/CamelCacheDeleteAll). Upon such an activity taking place
Cache ProcessorsThere are a set of nice processors with the ability to perform cache lookups and selectively replace payload content at the
Cache Usage SamplesExample 1: Configuring the cachefrom("cache://MyApplicationCache" + "?maxElementsInMemory=1000" + "&memoryStoreEvictionPolicy=" + "MemoryStoreEvictionPolicy.LFU" + "&overflowToDisk=true" + "&eternal=true" + "&timeToLiveSeconds=300" + "&timeToIdleSeconds=true" + "&diskPersistent=true" + "&diskExpiryThreadIntervalSeconds=300") Example 2: Adding keys to the cacheRouteBuilder builder = new RouteBuilder() { public void configure() { from("direct:start") .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_ADD)) .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")) .to("cache://TestCache1") } }; Example 2: Updating existing keys in a cacheRouteBuilder builder = new RouteBuilder() { public void configure() { from("direct:start") .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_UPDATE)) .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")) .to("cache://TestCache1") } }; Example 3: Deleting existing keys in a cacheRouteBuilder builder = new RouteBuilder() { public void configure() { from("direct:start") .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_DELETE)) .setHeader(CacheConstants.CACHE_KEY", constant("Ralph_Waldo_Emerson")) .to("cache://TestCache1") } }; Example 4: Deleting all existing keys in a cacheRouteBuilder builder = new RouteBuilder() { public void configure() { from("direct:start") .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_DELETEALL)) .to("cache://TestCache1"); } }; Example 5: Notifying any changes registering in a Cache to Processors and other ProducersRouteBuilder builder = new RouteBuilder() { public void configure() { from("cache://TestCache1") .process(new Processor() { public void process(Exchange exchange) throws Exception { String operation = (String) exchange.getIn().getHeader(CacheConstants.CACHE_OPERATION); String key = (String) exchange.getIn().getHeader(CacheConstants.CACHE_KEY); Object body = exchange.getIn().getBody(); // Do something } }) } }; Example 6: Using Processors to selectively replace payload with cache valuesRouteBuilder builder = new RouteBuilder() { public void configure() { //Message Body Replacer from("cache://TestCache1") .filter(header(CacheConstants.CACHE_KEY).isEqualTo("greeting")) .process(new CacheBasedMessageBodyReplacer("cache://TestCache1","farewell")) .to("direct:next"); //Message Token replacer from("cache://TestCache1") .filter(header(CacheConstants.CACHE_KEY).isEqualTo("quote")) .process(new CacheBasedTokenReplacer("cache://TestCache1","novel","#novel#")) .process(new CacheBasedTokenReplacer("cache://TestCache1","author","#author#")) .process(new CacheBasedTokenReplacer("cache://TestCache1","number","#number#")) .to("direct:next"); //Message XPath replacer from("cache://TestCache1"). .filter(header(CacheConstants.CACHE_KEY).isEqualTo("XML_FRAGMENT")) .process(new CacheBasedXPathReplacer("cache://TestCache1","book1","/books/book1")) .process (new CacheBasedXPathReplacer("cache://TestCache1","book2","/books/book2")) .to("direct:next"); } }; Example 7: Getting an entry from the Cachefrom("direct:start") // Prepare headers .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_GET)) .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")). .to("cache://TestCache1"). // Check if entry was not found .choice().when(header(CacheConstants.CACHE_ELEMENT_WAS_FOUND).isNull()). // If not found, get the payload and put it to cache .to("cxf:bean:someHeavyweightOperation"). .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_ADD)) .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")) .to("cache://TestCache1") .end() .to("direct:nextPhase"); Example 8: Checking for an entry in the CacheNote: CHECK command tests existence of the entry in the cache but doesn't place message to the body. from("direct:start") // Prepare headers .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_CHECK)) .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")). .to("cache://TestCache1"). // Check if entry was not found .choice().when(header(CacheConstants.CACHE_ELEMENT_WAS_FOUND).isNull()). // If not found, get the payload and put it to cache .to("cxf:bean:someHeavyweightOperation"). .setHeader(CacheConstants.CACHE_OPERATION, constant(CacheConstants.CACHE_OPERATION_ADD)) .setHeader(CacheConstants.CACHE_KEY, constant("Ralph_Waldo_Emerson")) .to("cache://TestCache1") .end(); Management of EHCacheEHCache has its own statistics and management from JMX. Here's a snippet on how to expose them via JMX in a Spring application context: <bean id="ehCacheManagementService" class="net.sf.ehcache.management.ManagementService" init-method="init" lazy-init="false"> <constructor-arg> <bean class="net.sf.ehcache.CacheManager" factory-method="getInstance"/> </constructor-arg> <constructor-arg> <bean class="org.springframework.jmx.support.JmxUtils" factory-method="locateMBeanServer"/> </constructor-arg> <constructor-arg value="true"/> <constructor-arg value="true"/> <constructor-arg value="true"/> <constructor-arg value="true"/> </bean> Of course you can do the same thing in straight Java: ManagementService.registerMBeans(CacheManager.getInstance(), mbeanServer, true, true, true, true); You can get cache hits, misses, in-memory hits, disk hits, size stats this way. You can also change CacheConfiguration parameters on the fly. Cache replication Camel 2.8+Camel Cache component is able to distribute cache across server nodes using several different replication mechanisms like: RMI, JGroups, JMS and Cache Server. There are two different ways To make it work: 1. you need to configure ehcache.xml manually OR 2. you have to take care about these three options:
Configuring Camel Cache replication using 1st option- the ehcache.xml file is a bit hard work as you have to configure all caches separately. So in a situation when the all names of caches are not know, using ehcache.xml is not a good idea. The second option is much better when you want to use many different caches as you do not need to define options per cache. This is because replication options are set per CacheManager and per CacheEndpoint. Also it is the only way when cache names are not know at the development phase.
Example: JMS cache replicationJMS replication is the most powerful and secured way. Used altogether with Camel Cache replication options is also the most easy way. Class ComponentAvailable as of Camel 2.4 The class: component binds beans to Camel message exchanges. It works in the same way as the Bean component but instead of looking up beans from a Registry it creates the bean based on the class name. URI formatclass:className[?options] Where className is the fully qualified class name to create and use as bean. Options
You can append query options to the URI in the following format, ?option=value&option=value&... UsingYou simply use the class component just as the Bean component but by specifying the fully qualified classname instead.
from("direct:start").to("class:org.apache.camel.component.bean.MyFooBean").to("mock:result");
You can also specify which method to invoke on the MyFooBean, for example hello:
from("direct:start").to("class:org.apache.camel.component.bean.MyFooBean?method=hello").to("mock:result");
Setting properties on the created instanceIn the endpoint uri you can specify properties to set on the created instance, for example if it has a setPrefix method:
from("direct:start")
.to("class:org.apache.camel.component.bean.MyPrefixBean?prefix=Bye")
.to("mock:result");
And you can also use the # syntax to refer to properties to be looked up in the Registry.
from("direct:start")
.to("class:org.apache.camel.component.bean.MyPrefixBean?cool=#foo")
.to("mock:result");
Which will lookup a bean from the Registry with the id foo and invoke the setCool method on the created instance of the MyPrefixBean class.
See AlsoCometd ComponentThe cometd: component is a transport for working with the jetty implementation of the cometd/bayeux protocol. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-cometd</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
cometd://host:port/channelName[?options]
The channelName represents a topic that can be subscribed to by the Camel endpoints. Examplescometd://localhost:8080/service/mychannel cometds://localhost:8443/service/mychannel where cometds: represents an SSL configured endpoint. See this blog entry by David Greco who contributed this component to Apache Camel, for a full sample. Options
You can append query options to the URI in the following format, ?option=value&option=value&... Here is some examples on How to pass the parameters For file (for webapp resources located in the Web Application directory --> cometd://localhost:8080?resourceBase=file./webapp AuthenticationAvailable as of Camel 2.8 You can configure custom SecurityPolicy and Extension's to the CometdComponent which allows you to use authentication as documented here Setting up SSL for Cometd ComponentUsing the JSSE Configuration UtilityAs of Camel 2.9, the Cometd component supports SSL/TLS configuration through the Camel JSSE Configuration Utility. This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the Cometd component. Programmatic configuration of the componentKeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); TrustManagersParameters tmp = new TrustManagersParameters(); tmp.setKeyStore(ksp); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); scp.setTrustManagers(tmp); CometdComponent commetdComponent = getContext().getComponent("cometds", CometdComponent.class); commetdComponent.setSslContextParameters(scp); Spring DSL based configuration of endpoint
...
<camel:sslContextParameters
id="sslContextParameters">
<camel:keyManagers
keyPassword="keyPassword">
<camel:keyStore
resource="/users/home/server/keystore.jks"
password="keystorePassword"/>
</camel:keyManagers>
<camel:trustManagers>
<camel:keyStore
resource="/users/home/server/keystore.jks"
password="keystorePassword"/>
</camel:keyManagers>
</camel:sslContextParameters>...
...
<to uri="cometds://127.0.0.1:443/service/test?baseResource=file:./target/test-classes/webapp&timeout=240000&interval=0&maxInterval=30000&multiFrameInterval=1500&jsonCommented=true&logLevel=2&sslContextParameters=#sslContextParameters"/>...
See AlsoContext ComponentAvailable as of Camel 2.7 The context component allows you to create new Camel Components from a CamelContext with a number of routes which is then treated as a black box, allowing you to refer to the local endpoints within the component from other CamelContexts. It is similar to the Routebox component in idea, though the Context component tries to be really simple for end users; just a simple convention over configuration approach to refer to local endpoints inside the CamelContext Component. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-context</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatcontext:camelContextId:localEndpointName[?options] Or you can omit the "context:" prefix. camelContextId:localEndpointName[?options]
You can append query options to the URI in the following format, ?option=value&option=value&... ExampleIn this example we'll create a black box context, then we'll use it from another CamelContext. Defining the context componentFirst you need to create a CamelContext, add some routes in it, start it and then register the CamelContext into the Registry (JNDI, Spring, Guice or OSGi etc). This can be done in the usual Camel way from this test case (see the createRegistry() method); this example shows Java and JNDI being used... // lets create our black box as a camel context and a set of routes DefaultCamelContext blackBox = new DefaultCamelContext(registry); blackBox.setName("blackBox"); blackBox.addRoutes(new RouteBuilder() { @Override public void configure() throws Exception { // receive purchase orders, lets process it in some way then send an invoice // to our invoice endpoint from("direct:purchaseOrder"). setHeader("received").constant("true"). to("direct:invoice"); } }); blackBox.start(); registry.bind("accounts", blackBox); Notice in the above route we are using pure local endpoints (direct and seda). Also note we expose this CamelContext using the accounts ID. We can do the same thing in Spring via <camelContext id="accounts" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:purchaseOrder"/> ... <to uri="direct:invoice"/> </route> </camelContext> Using the context componentThen in another CamelContext we can then refer to this "accounts black box" by just sending to accounts:purchaseOrder and consuming from accounts:invoice. If you prefer to be more verbose and explicit you could use context:accounts:purchaseOrder or even context:accounts:direct://purchaseOrder if you prefer. But using logical endpoint URIs is preferred as it hides the implementation detail and provides a simple logical naming scheme. For example if we wish to then expose this accounts black box on some middleware (outside of the black box) we can do things like... <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <!-- consume from an ActiveMQ into the black box --> <from uri="activemq:Accounts.PurchaseOrders"/> <to uri="accounts:purchaseOrders"/> </route> <route> <!-- lets send invoices from the black box to a different ActiveMQ Queue --> <from uri="accounts:invoice"/> <to uri="activemq:UK.Accounts.Invoices"/> </route> </camelContext> Naming endpointsA context component instance can have many public input and output endpoints that can be accessed from outside it's CamelContext. When there are many it is recommended that you use logical names for them to hide the middleware as shown above. However when there is only one input, output or error/dead letter endpoint in a component we recommend using the common posix shell names in, out and err Crypto component for Digital SignaturesAvailable as of Camel 2.3 Using Camel cryptographic endpoints and Java's Cryptographic extension it is easy to create Digital Signatures for Exchanges. Camel provides a pair of flexible endpoints which get used in concert to create a signature for an exchange in one part of the exchange's workflow and then verify the signature in a later part of the workflow. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-crypto</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> IntroductionDigital signatures make use Asymmetric Cryptographic techniques to sign messages. From a (very) high level, the algorithms use pairs of complimentary keys with the special property that data encrypted with one key can only be decrypted with the other. One, the private key, is closely guarded and used to 'sign' the message while the other, public key, is shared around to anyone interested in verifying your messages. Messages are signed by encrypting a digest of the message with the private key. This encrypted digest is transmitted along with the message. On the other side the verifier recalculates the message digest and uses the public key to decrypt the the digest in the signature. If both digest match the verifier knows only the holder of the private key could have created the signature. Camel uses the Signature service from the Java Cryptographic Extension to do all the heavy cryptographic lifting required to create exchange signatures. The following are some excellent sources for explaining the mechanics of Cryptography, Message digests and Digital Signatures and how to leverage them with the JCE.
URI formatAs mentioned Camel provides a pair of crypto endpoints to create and verify signatures crypto:sign:name[?options] crypto:verify:name[?options]
In order to correctly function, sign and verify need to share a pair of keys, sign requiring a PrivateKey and verify a PublicKey (or a Certificate containing one). Using the JCE is is very simple to generate these key pairs but it is usually most secure to use a KeyStore to house and share your keys. The DSL is very flexible about how keys are supplied and provides a number of mechanisms. Note a crypto:sign endpoint is typically defined in one route and the complimentary crypto:verify in another, though for simplicity in the examples they appear one after the other. It goes without saying that both sign and verify should be configured identically. Options
Using1) Raw keysThe most basic way to way to sign an verify an exchange is with a KeyPair as follows. from("direct:keypair").to("crypto:sign://basic?privateKey=#myPrivateKey", "crypto:verify://basic?publicKey=#myPublicKey", "mock:result"); The same can be achieved with the Spring XML Extensions using references to keys <route> <from uri="direct:keypair"/> <to uri="crypto:sign://basic?privateKey=#myPrivateKey" /> <to uri="crypto:verify://basic?publicKey=#myPublicKey" /> <to uri="mock:result"/> </route> 2) KeyStores and Aliases.The JCE provides a very versatile KeyStore for housing pairs of PrivateKeys and Certificates keeping them encrypted and password protected. They can be retrieved from it by applying an alias to the retrieval apis. There are a number of ways to get keys and Certificates into a keystore most often this is done with the external 'keytool' application. This is a good example of using keytool to create a KeyStore with a self signed Cert and Private key. The examples use a Keystore with a key and cert aliased by 'bob'. The password for the keystore and the key is 'letmein' The following shows how to use a Keystore via the Fluent builders, it also shows how to load and initialize the keystore. from("direct:keystore").to("crypto:sign://keystore?keystore=#keystore&alias=bob&password=letmein", "crypto:verify://keystore?keystore=#keystore&alias=bob", "mock:result"); Again in Spring a ref is used to lookup an actual keystore instance. <route> <from uri="direct:keystore"/> <to uri="crypto:sign://keystore?keystore=#keystore&alias=bob&password=letmein" /> <to uri="crypto:verify://keystore?keystore=#keystore&alias=bob" /> <to uri="mock:result"/> </route> 3) Changing JCE Provider and AlgorithmChanging the Signature algorithm or the Security provider is a simple matter of specifying their names. You will need to also use Keys that are compatible with the algorithm you choose. KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA"); keyGen.initialize(512, new SecureRandom()); keyPair = keyGen.generateKeyPair(); PrivateKey privateKey = keyPair.getPrivate(); PublicKey publicKey = keyPair.getPublic(); // we can set the keys explicitly on the endpoint instances. context.getEndpoint("crypto:sign://rsa?algorithm=MD5withRSA", DigitalSignatureEndpoint.class).setPrivateKey(privateKey); context.getEndpoint("crypto:verify://rsa?algorithm=MD5withRSA", DigitalSignatureEndpoint.class).setPublicKey(publicKey); from("direct:algorithm").to("crypto:sign://rsa?algorithm=MD5withRSA", "crypto:verify://rsa?algorithm=MD5withRSA", "mock:result"); from("direct:provider").to("crypto:sign://provider?privateKey=#myPrivateKey&provider=SUN", "crypto:verify://provider?publicKey=#myPublicKey&provider=SUN", "mock:result"); or <route> <from uri="direct:algorithm"/> <to uri="crypto:sign://rsa?algorithm=MD5withRSA&privateKey=#rsaPrivateKey" /> <to uri="crypto:verify://rsa?algorithm=MD5withRSA&publicKey=#rsaPublicKey" /> <to uri="mock:result"/> </route> <route> <from uri="direct:provider"/> <to uri="crypto:sign://provider?privateKey=#myPrivateKey&provider=SUN" /> <to uri="crypto:verify://provider?publicKey=#myPublicKey&provider=SUN" /> <to uri="mock:result"/> </route> 4) Changing the Signature Mesasge HeaderIt may be desirable to change the message header used to store the signature. A different header name can be specified in the route definition as follows from("direct:signature-header").to("crypto:sign://another?privateKey=#myPrivateKey&signatureHeader=AnotherDigitalSignature", "crypto:verify://another?publicKey=#myPublicKey&signatureHeader=AnotherDigitalSignature", "mock:result"); or <route> <from uri="direct:signature-header"/> <to uri="crypto:sign://another?privateKey=#myPrivateKey&signatureHeader=AnotherDigitalSignature" /> <to uri="crypto:verify://another?publicKey=#myPublicKey&signatureHeader=AnotherDigitalSignature" /> <to uri="mock:result"/> </route> 5) Changing the buffersizeIn case you need to update the size of the buffer... from("direct:buffersize").to("crypto:sign://buffer?privateKey=#myPrivateKey&buffersize=1024", "crypto:verify://buffer?publicKey=#myPublicKey&buffersize=1024", "mock:result"); or <route> <from uri="direct:buffersize" /> <to uri="crypto:sign://buffer?privateKey=#myPrivateKey&buffersize=1024" /> <to uri="crypto:verify://buffer?publicKey=#myPublicKey&buffersize=1024" /> <to uri="mock:result"/> </route> 6) Supplying Keys dynamically.When using a Recipient list or similar EIP the recipient of an exchange can vary dynamically. Using the same key across all recipients may neither be feasible or desirable. It would be useful to be able to specify the signature keys dynamically on a per exchange basis. The exchange could then be dynamically enriched with the key of its target recipient prior to signing. To facilitate this the signature mechanisms allow for keys to be supplied dynamically via the message headers below
from("direct:headerkey-sign").to("crypto:sign://alias"); from("direct:headerkey-verify").to("crypto:verify://alias", "mock:result"); or <route> <from uri="direct:headerkey-sign"/> <to uri="crypto:sign://headerkey" /> </route> <route> <from uri="direct:headerkey-verify"/> <to uri="crypto:verify://headerkey" /> <to uri="mock:result"/> </route> Better again would be to dynamically supply a keystore alias. Again the alias can be supplied in a message header
from("direct:alias-sign").to("crypto:sign://alias?keystore=#keystore"); from("direct:alias-verify").to("crypto:verify://alias?keystore=#keystore", "mock:result"); or <route> <from uri="direct:alias-sign"/> <to uri="crypto:sign://alias?keystore=#keystore" /> </route> <route> <from uri="direct:alias-verify"/> <to uri="crypto:verify://alias?keystore=#keystore" /> <to uri="mock:result"/> </route> The header would be set as follows Exchange unsigned = getMandatoryEndpoint("direct:alias-sign").createExchange(); unsigned.getIn().setBody(payload); unsigned.getIn().setHeader(DigitalSignatureConstants.KEYSTORE_ALIAS, "bob"); unsigned.getIn().setHeader(DigitalSignatureConstants.KEYSTORE_PASSWORD, "letmein".toCharArray()); template.send("direct:alias-sign", unsigned); Exchange signed = getMandatoryEndpoint("direct:alias-sign").createExchange(); signed.getIn().copyFrom(unsigned.getOut()); signed.getIn().setHeader(KEYSTORE_ALIAS, "bob"); template.send("direct:alias-verify", signed); See Also
CXF Component
The cxf: component provides integration with Apache CXF for connecting to JAX-WS services hosted in CXF.
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-cxf</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
URI formatcxf:bean:cxfEndpoint[?options] Where cxfEndpoint represents a bean ID that references a bean in the Spring bean registry. With this URI format, most of the endpoint details are specified in the bean definition.
cxf://someAddress[?options]
Where someAddress specifies the CXF endpoint's address. With this URI format, most of the endpoint details are specified using options. For either style above, you can append options to the URI as follows: cxf:bean:cxfEndpoint?wsdlURL=wsdl/hello_world.wsdl&dataFormat=PAYLOAD Options
The serviceName and portName are QNames, so if you provide them be sure to prefix them with their {namespace} as shown in the examples above. NOTE From CAMEL 1.5.1 , the serviceClass for a CXF producer (that is, the to endpoint) should be a Java interface. The descriptions of the dataformats
You can determine the data format mode of an exchange by retrieving the exchange property, CamelCXFDataFormat. The exchange key constant is defined in org.apache.camel.component.cxf.CxfConstants.DATA_FORMAT_PROPERTY. How to enable CXF's LoggingOutInterceptor in MESSAGE modeCXF's LoggingOutInterceptor outputs outbound message that goes on the wire to logging system (Java Util Logging). Since the LoggingOutInterceptor is in PRE_STREAM phase (but PRE_STREAM phase is removed in MESSAGE mode), you have to configure LoggingOutInterceptor to be run during the WRITE phase. The following is an example. <bean id="loggingOutInterceptor" class="org.apache.cxf.interceptor.LoggingOutInterceptor"> <!-- it really should have been user-prestream but CXF does have such phase! --> <constructor-arg value="target/write"/> </bean> <cxf:cxfEndpoint id="serviceEndpoint" address="http://localhost:${CXFTestSupport.port2}/LoggingInterceptorInMessageModeTest/helloworld" serviceClass="org.apache.camel.component.cxf.HelloService"> <cxf:outInterceptors> <ref bean="loggingOutInterceptor"/> </cxf:outInterceptors> <cxf:properties> <entry key="dataFormat" value="MESSAGE"/> </cxf:properties> </cxf:cxfEndpoint> Description of relayHeaders optionThere are in-band and out-of-band on-the-wire headers from the perspective of a JAXWS WSDL-first developer. The in-band headers are headers that are explicitly defined as part of the WSDL binding contract for an endpoint such as SOAP headers. The out-of-band headers are headers that are serialized over the wire, but are not explicitly part of the WSDL binding contract. Headers relaying/filtering is bi-directional. When a route has a CXF endpoint and the developer needs to have on-the-wire headers, such as SOAP headers, be relayed along the route to be consumed say by another JAXWS endpoint, then relayHeaders should be set to true, which is the default value. Available in Release 1.6.1 and after (only in POJO mode)The relayHeaders=true express an intent to relay the headers. The actual decision on whether a given header is relayed is delegated to a pluggable instance that implements the MessageHeadersRelay interface. A concrete implementation of MessageHeadersRelay will be consulted to decide if a header needs to be relayed or not. There is already an implementation of SoapMessageHeadersRelay which binds itself to well-known SOAP name spaces. Currently only out-of-band headers are filtered, and in-band headers will always be relayed when relayHeaders=true. If there is a header on the wire, whose name space is unknown to the runtime, then a fall back DefaultMessageHeadersRelay will be used, which simply allows all headers to be relayed. The relayHeaders=false setting asserts that all headers in-band and out-of-band will be dropped. You can plugin your own MessageHeadersRelay implementations overriding or adding additional ones to the list of relays. In order to override a preloaded relay instance just make sure that your MessageHeadersRelay implementation services the same name spaces as the one you looking to override. Also note, that the overriding relay has to service all of the name spaces as the one you looking to override, or else a runtime exception on route start up will be thrown as this would introduce an ambiguity in name spaces to relay instance mappings. <cxf:cxfEndpoint ...> <cxf:properties> <entry key="org.apache.camel.cxf.message.headers.relays"> <list> <ref bean="customHeadersRelay"/> </list> </entry> </cxf:properties> </cxf:cxfEndpoint> <bean id="customHeadersRelay" class="org.apache.camel.component.cxf.soap.headers.CustomHeadersRelay"/> Take a look at the tests that show how you'd be able to relay/drop headers here: Changes since Release 2.0
You can find more advanced examples which show how to provide interceptors , properties and handlers here: NOTE <cxf:cxfEndpoint id="testEndpoint" address="http://localhost:9000/router" serviceClass="org.apache.camel.component.cxf.HelloService" endpointName="s:PortName" serviceName="s:ServiceName" xmlns:s="http://www.example.com/test"> <cxf:properties> <entry key="dataFormat" value="MESSAGE"/> <entry key="setDefaultBus" value="true"/> </cxf:properties> </cxf:cxfEndpoint> Configuring the CXF Endpoints with Apache Aries Blueprint.Since camel 2.8 there is support for utilizing aries blueprint dependency injection for your CXF endpoints. Example <blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0" xmlns:camel-cxf="http://camel.apache.org/schema/blueprint/cxf" xmlns:cxfcore="http://cxf.apache.org/blueprint/core" xsi:schemaLocation="http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd"> <camel-cxf:cxfEndpoint id="routerEndpoint" address="http://localhost:9001/router" serviceClass="org.apache.servicemix.examples.cxf.HelloWorld"> <camel-cxf:properties> <entry key="dataFormat" value="MESSAGE"/> </camel-cxf:properties> </camel-cxf:cxfEndpoint> <camel-cxf:cxfEndpoint id="serviceEndpoint" address="http://localhost:9000/SoapContext/SoapPort" serviceClass="org.apache.servicemix.examples.cxf.HelloWorld"> </camel-cxf:cxfEndpoint> <camelContext xmlns="http://camel.apache.org/schema/blueprint"> <route> <from uri="routerEndpoint"/> <to uri="log:request"/> </route> </camelContext> </blueprint> Currently the endpoint element is the first supported CXF namespacehandler. You can also use the bean references just as in spring <blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0" xmlns:jaxws="http://cxf.apache.org/blueprint/jaxws" xmlns:cxf="http://cxf.apache.org/blueprint/core" xmlns:camel="http://camel.apache.org/schema/blueprint" xmlns:camelcxf="http://camel.apache.org/schema/blueprint/cxf" xsi:schemaLocation=" http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd http://cxf.apache.org/blueprint/jaxws http://cxf.apache.org/schemas/blueprint/jaxws.xsd http://cxf.apache.org/blueprint/core http://cxf.apache.org/schemas/blueprint/core.xsd "> <camelcxf:cxfEndpoint id="reportIncident" address="/camel-example-cxf-blueprint/webservices/incident" wsdlURL="META-INF/wsdl/report_incident.wsdl" serviceClass="org.apache.camel.example.reportincident.ReportIncidentEndpoint"> </camelcxf:cxfEndpoint> <bean id="reportIncidentRoutes" class="org.apache.camel.example.reportincident.ReportIncidentRoutes" /> <camelContext xmlns="http://camel.apache.org/schema/blueprint"> <routeBuilder ref="reportIncidentRoutes"/> </camelContext> </blueprint> How to make the camel-cxf component use log4j instead of java.util.loggingCXF's default logger is java.util.logging. If you want to change it to log4j, proceed as follows. Create a file, in the classpath, named META-INF/cxf/org.apache.cxf.logger. This file should contain the fully-qualified name of the class, org.apache.cxf.common.logging.Log4jLogger, with no comments, on a single line. How to let camel-cxf response message with xml start documentIf you are using some soap client such as PHP, you will get this kind of error, because CXF doesn't add the XML start document "<?xml version="1.0" encoding="utf-8"?>" Error:sendSms: SoapFault exception: [Client] looks like we got no XML document in [...] To resolved this issue, you just need to tell StaxOutInterceptor to write the XML start document for you. public class WriteXmlDeclarationInterceptor extends AbstractPhaseInterceptor<SoapMessage> { public WriteXmlDeclarationInterceptor() { super(Phase.PRE_STREAM); addBefore(StaxOutInterceptor.class.getName()); } public void handleMessage(SoapMessage message) throws Fault { message.put("org.apache.cxf.stax.force-start-document", Boolean.TRUE); } } You can add a customer interceptor like this and configure it into you camel-cxf endpont <cxf:cxfEndpoint id="routerEndpoint" address="http://localhost:${CXFTestSupport.port2}/CXFGreeterRouterTest/CamelContext/RouterPort" serviceClass="org.apache.hello_world_soap_http.GreeterImpl"> <cxf:outInterceptors> <!-- This interceptor will force the CXF server send the XML start document to client --> <bean class="org.apache.camel.component.cxf.WriteXmlDeclarationInterceptor"/> </cxf:outInterceptors> <cxf:properties> <!-- Set the publishedEndpointUrl which could override the service address from generated WSDL as you want --> <entry key="publishedEndpointUrl" value="http://www.simple.com/services/test" /> </cxf:properties> </cxf:cxfEndpoint> Or adding a message header for it like this if you are using Camel 2.4. // set up the response context which force start document Map<String, Object> map = new HashMap<String, Object>(); map.put("org.apache.cxf.stax.force-start-document", Boolean.TRUE); exchange.getOut().setHeader(Client.RESPONSE_CONTEXT, map); How to consume a message from a camel-cxf endpoint in POJO data formatThe camel-cxf endpoint consumer POJO data format is based on the cxf invoker, so the message header has a property with the name of CxfConstants.OPERATION_NAME and the message body is a list of the SEI method parameters. public class PersonProcessor implements Processor { private static final transient Logger LOG = LoggerFactory.getLogger(PersonProcessor.class); @SuppressWarnings("unchecked") public void process(Exchange exchange) throws Exception { LOG.info("processing exchange in camel"); BindingOperationInfo boi = (BindingOperationInfo)exchange.getProperty(BindingOperationInfo.class.toString()); if (boi != null) { LOG.info("boi.isUnwrapped" + boi.isUnwrapped()); } // Get the parameters list which element is the holder. MessageContentsList msgList = (MessageContentsList)exchange.getIn().getBody(); Holder<String> personId = (Holder<String>)msgList.get(0); Holder<String> ssn = (Holder<String>)msgList.get(1); Holder<String> name = (Holder<String>)msgList.get(2); if (personId.value == null || personId.value.length() == 0) { LOG.info("person id 123, so throwing exception"); // Try to throw out the soap fault message org.apache.camel.wsdl_first.types.UnknownPersonFault personFault = new org.apache.camel.wsdl_first.types.UnknownPersonFault(); personFault.setPersonId(""); org.apache.camel.wsdl_first.UnknownPersonFault fault = new org.apache.camel.wsdl_first.UnknownPersonFault("Get the null value of person name", personFault); // Since camel has its own exception handler framework, we can't throw the exception to trigger it // We just set the fault message in the exchange for camel-cxf component handling and return exchange.getOut().setFault(true); exchange.getOut().setBody(fault); return; } name.value = "Bonjour"; ssn.value = "123"; LOG.info("setting Bonjour as the response"); // Set the response message, first element is the return value of the operation, // the others are the holders of method parameters exchange.getOut().setBody(new Object[] {null, personId, ssn, name}); } } How to prepare the message for the camel-cxf endpoint in POJO data formatThe camel-cxf endpoint producer is based on the cxf client API. First you need to specify the operation name in the message header, then add the method parameters to a list, and initialize the message with this parameter list. The response message's body is a messageContentsList, you can get the result from that list. NOTE After Camel 1.5 , we change the message body from object array to message content list. If you still want to get the object array from the message body, you can get the body using message.getbody(Object[].class), as follows: Exchange senderExchange = new DefaultExchange(context, ExchangePattern.InOut); final List<String> params = new ArrayList<String>(); // Prepare the request message for the camel-cxf procedure params.add(TEST_MESSAGE); senderExchange.getIn().setBody(params); senderExchange.getIn().setHeader(CxfConstants.OPERATION_NAME, ECHO_OPERATION); Exchange exchange = template.send("direct:EndpointA", senderExchange); org.apache.camel.Message out = exchange.getOut(); // The response message's body is an MessageContentsList which first element is the return value of the operation, // If there are some holder parameters, the holder parameter will be filled in the reset of List. // The result will be extract from the MessageContentsList with the String class type MessageContentsList result = (MessageContentsList)out.getBody(); LOG.info("Received output text: " + result.get(0)); Map<String, Object> responseContext = CastUtils.cast((Map<?, ?>)out.getHeader(Client.RESPONSE_CONTEXT)); assertNotNull(responseContext); assertEquals("We should get the response context here", "UTF-8", responseContext.get(org.apache.cxf.message.Message.ENCODING)); assertEquals("Reply body on Camel is wrong", "echo " + TEST_MESSAGE, result.get(0)); How to deal with the message for a camel-cxf endpoint in PAYLOAD data formatPAYLOAD means that you process the payload message from the SOAP envelope. You can use the Header.HEADER_LIST as the key to set or get the SOAP headers and use the List<Element> to set or get SOAP body elements. protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from(SIMPLE_ENDPOINT_URI + "&dataFormat=PAYLOAD").to("log:info").process(new Processor() { public void process(final Exchange exchange) throws Exception { Message inMessage = exchange.getIn(); if (inMessage instanceof CxfMessage) { CxfMessage cxfInMessage = (CxfMessage) inMessage; CxfMessage cxfOutMessage = (CxfMessage) exchange.getOut(); List<Element> inElements = cxfInMessage.getMessage().get(List.class); List<Element> outElements = new ArrayList<Element>(); XmlConverter converter = new XmlConverter(); String documentString = ECHO_RESPONSE; if (inElements.get(0).getLocalName().equals("echoBoolean")) { documentString = ECHO_BOOLEAN_RESPONSE; } org.apache.cxf.message.Exchange ex = ((CxfExchange)exchange).getExchange(); Endpoint ep = ex.get(Endpoint.class); org.apache.cxf.message.Message response = ep.getBinding().createMessage(); Document outDocument = converter.toDOMDocument(documentString); outElements.add(outDocument.getDocumentElement()); response.put(List.class, outElements); cxfOutMessage.setMessage(response); } } }); } }; } Change in 2.0, There is no more CxfMessage, we just use the common Camel DefaultMessageImpl under layer. Message.getBody() will return an org.apache.camel.component.cxf.CxfPayload object, which has getters for SOAP message headers and Body elements. This change enables decoupling the native CXF message from the Camel message. protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from(simpleEndpointURI + "&dataFormat=PAYLOAD").to("log:info").process(new Processor() { @SuppressWarnings("unchecked") public void process(final Exchange exchange) throws Exception { CxfPayload<SoapHeader> requestPayload = exchange.getIn().getBody(CxfPayload.class); List<Source> inElements = requestPayload.getBodySources(); List<Source> outElements = new ArrayList<Source>(); // You can use a customer toStringConverter to turn a CxfPayLoad message into String as you want String request = exchange.getIn().getBody(String.class); XmlConverter converter = new XmlConverter(); String documentString = ECHO_RESPONSE; Element in = new XmlConverter().toDOMElement(inElements.get(0)); // Just check the element namespace if (!in.getNamespaceURI().equals(ELEMENT_NAMESPACE)) { throw new IllegalArgumentException("Wrong element namespace"); } if (in.getLocalName().equals("echoBoolean")) { documentString = ECHO_BOOLEAN_RESPONSE; checkRequest("ECHO_BOOLEAN_REQUEST", request); } else { documentString = ECHO_RESPONSE; checkRequest("ECHO_REQUEST", request); } Document outDocument = converter.toDOMDocument(documentString); outElements.add(new DOMSource(outDocument.getDocumentElement())); // set the payload header with null CxfPayload<SoapHeader> responsePayload = new CxfPayload<SoapHeader>(null, outElements, null); exchange.getOut().setBody(responsePayload); } }); } }; } How to get and set SOAP headers in POJO modePOJO means that the data format is a "list of Java objects" when the Camel-cxf endpoint produces or consumes Camel exchanges. Even though Camel expose message body as POJOs in this mode, Camel-cxf still provides access to read and write SOAP headers. However, since CXF interceptors remove in-band SOAP headers from Header list after they have been processed, only out-of-band SOAP headers are available to Camel-cxf in POJO mode. The following example illustrate how to get/set SOAP headers. Suppose we have a route that forwards from one Camel-cxf endpoint to another. That is, SOAP Client -> Camel -> CXF service. We can attach two processors to obtain/insert SOAP headers at (1) before request goes out to the CXF service and (2) before response comes back to the SOAP Client. Processor (1) and (2) in this example are InsertRequestOutHeaderProcessor and InsertResponseOutHeaderProcessor. Our route looks like this: <route> <from uri="cxf:bean:routerRelayEndpointWithInsertion"/> <process ref="InsertRequestOutHeaderProcessor" /> <to uri="cxf:bean:serviceRelayEndpointWithInsertion"/> <process ref="InsertResponseOutHeaderProcessor" /> </route> In 2.x SOAP headers are propagated to and from Camel Message headers. The Camel message header name is "org.apache.cxf.headers.Header.list" which is a constant defined in CXF (org.apache.cxf.headers.Header.HEADER_LIST). The header value is a List of CXF SoapHeader objects (org.apache.cxf.binding.soap.SoapHeader). The following snippet is the InsertResponseOutHeaderProcessor (that insert a new SOAP header in the response message). The way to access SOAP headers in both InsertResponseOutHeaderProcessor and InsertRequestOutHeaderProcessor are actually the same. The only difference between the two processors is setting the direction of the inserted SOAP header. public static class InsertResponseOutHeaderProcessor implements Processor { public void process(Exchange exchange) throws Exception { List<SoapHeader> soapHeaders = CastUtils.cast((List<?>)exchange.getIn().getHeader(Header.HEADER_LIST)); // Insert a new header String xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?><outofbandHeader " + "xmlns=\"http://cxf.apache.org/outofband/Header\" hdrAttribute=\"testHdrAttribute\" " + "xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\" soap:mustUnderstand=\"1\">" + "<name>New_testOobHeader</name><value>New_testOobHeaderValue</value></outofbandHeader>"; SoapHeader newHeader = new SoapHeader(soapHeaders.get(0).getName(), DOMUtils.readXml(new StringReader(xml)).getDocumentElement()); // make sure direction is OUT since it is a response message. newHeader.setDirection(Direction.DIRECTION_OUT); //newHeader.setMustUnderstand(false); soapHeaders.add(newHeader); } } In 1.x SOAP headers are not propagated to and from Camel Message headers. Users have to go deeper into CXF APIs to access SOAP headers. Also, accessing the SOAP headers in a request message is slight different than in a response message. The InsertRequestOutHeaderProcessor and InsertResponseOutHeaderProcessor are as follow. public static class InsertRequestOutHeaderProcessor implements Processor { public void process(Exchange exchange) throws Exception { CxfMessage message = exchange.getIn().getBody(CxfMessage.class); Message cxf = message.getMessage(); List<SoapHeader> soapHeaders = (List)cxf.get(Header.HEADER_LIST); // Insert a new header String xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?><outofbandHeader " + "xmlns=\"http://cxf.apache.org/outofband/Header\" hdrAttribute=\"testHdrAttribute\" " + "xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\" soap:mustUnderstand=\"1\">" + "<name>New_testOobHeader</name><value>New_testOobHeaderValue</value></outofbandHeader>"; SoapHeader newHeader = new SoapHeader(soapHeaders.get(0).getName(), DOMUtils.readXml(new StringReader(xml)).getDocumentElement()); // make sure direction is IN since it is a request message. newHeader.setDirection(Direction.DIRECTION_IN); //newHeader.setMustUnderstand(false); soapHeaders.add(newHeader); } } public static class InsertResponseOutHeaderProcessor implements Processor { public void process(Exchange exchange) throws Exception { CxfMessage message = exchange.getIn().getBody(CxfMessage.class); Map responseContext = (Map)message.getMessage().get(Client.RESPONSE_CONTEXT); List<SoapHeader> soapHeaders = (List)responseContext.get(Header.HEADER_LIST); // Insert a new header String xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?><outofbandHeader " + "xmlns=\"http://cxf.apache.org/outofband/Header\" hdrAttribute=\"testHdrAttribute\" " + "xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\" soap:mustUnderstand=\"1\">" + "<name>New_testOobHeader</name><value>New_testOobHeaderValue</value></outofbandHeader>"; SoapHeader newHeader = new SoapHeader(soapHeaders.get(0).getName(), DOMUtils.readXml(new StringReader(xml)).getDocumentElement()); // make sure direction is OUT since it is a response message. newHeader.setDirection(Direction.DIRECTION_OUT); //newHeader.setMustUnderstand(false); soapHeaders.add(newHeader); } } How to get and set SOAP headers in PAYLOAD modeWe've already shown how to access SOAP message (CxfPayload object) in PAYLOAD mode (See "How to deal with the message for a camel-cxf endpoint in PAYLOAD data format"). In 2.x Once you obtain a CxfPayload object, you can invoke the CxfPayload.getHeaders() method that returns a List of DOM Elements (SOAP headers). from(getRouterEndpointURI()).process(new Processor() { @SuppressWarnings("unchecked") public void process(Exchange exchange) throws Exception { CxfPayload<SoapHeader> payload = exchange.getIn().getBody(CxfPayload.class); List<Source> elements = payload.getBodySources(); assertNotNull("We should get the elements here", elements); assertEquals("Get the wrong elements size", 1, elements.size()); Element el = new XmlConverter().toDOMElement(elements.get(0)); elements.set(0, new DOMSource(el)); assertEquals("Get the wrong namespace URI", "http://camel.apache.org/pizza/types", el.getNamespaceURI()); List<SoapHeader> headers = payload.getHeaders(); assertNotNull("We should get the headers here", headers); assertEquals("Get the wrong headers size", headers.size(), 1); assertEquals("Get the wrong namespace URI", ((Element)(headers.get(0).getObject())).getNamespaceURI(), "http://camel.apache.org/pizza/types"); } }) .to(getServiceEndpointURI()); *In 1.x" You can get/set to the CXF Message by the key "org.apache.cxf.headers.Header.list" which is a constant defined in CXF (org.apache.cxf.headers.Header.HEADER_LIST). from(routerEndpointURI).process(new Processor() { @SuppressWarnings("unchecked") public void process(Exchange exchange) throws Exception { Message inMessage = exchange.getIn(); CxfMessage message = (CxfMessage) inMessage; List<Element> elements = message.getMessage().get(List.class); assertNotNull("We should get the payload elements here" , elements); assertEquals("Get the wrong elements size" , elements.size(), 1); assertEquals("Get the wrong namespace URI" , elements.get(0).getNamespaceURI(), "http://camel.apache.org/pizza/types"); List<SoapHeader> headers = CastUtils.cast((List<?>)message.getMessage().get(Header.HEADER_LIST)); assertNotNull("We should get the headers here", headers); assertEquals("Get the wrong headers size", headers.size(), 1); assertEquals("Get the wrong namespace URI" , ((Element)(headers.get(0).getObject())).getNamespaceURI(), "http://camel.apache.org/pizza/types"); } }) .to(serviceEndpointURI); SOAP headers are not available in MESSAGE modeSOAP headers are not available in MESSAGE mode as SOAP processing is skipped. How to throw a SOAP Fault from CamelIf you are using a camel-cxf endpoint to consume the SOAP request, you may need to throw the SOAP Fault from the camel context. SOAP_FAULT = new SoapFault(EXCEPTION_MESSAGE, SoapFault.FAULT_CODE_CLIENT);
Element detail = SOAP_FAULT.getOrCreateDetail();
Document doc = detail.getOwnerDocument();
Text tn = doc.createTextNode(DETAIL_TEXT);
detail.appendChild(tn);
Then throw it as you like from(routerEndpointURI).setFaultBody(constant(SOAP_FAULT)); If your CXF endpoint is working in the MESSAGE data format, you could set the the SOAP Fault message in the message body and set the response code in the message header. from(routerEndpointURI).process(new Processor() { public void process(Exchange exchange) throws Exception { Message out = exchange.getOut(); // Set the message body with the out.setBody(this.getClass().getResourceAsStream("SoapFaultMessage.xml")); // Set the response code here out.setHeader(org.apache.cxf.message.Message.RESPONSE_CODE, new Integer(500)); } }); NOTE the response code setting only works in Camel's version >= 1.5.1 Same for using POJO data format. You can set the SOAPFault on the out body and also indicate it's a fault by calling Message.setFault(true): from("direct:start").onException(SoapFault.class).maximumRedeliveries(0).handled(true) .process(new Processor() { public void process(Exchange exchange) throws Exception { SoapFault fault = exchange .getProperty(Exchange.EXCEPTION_CAUGHT, SoapFault.class); exchange.getOut().setFault(true); exchange.getOut().setBody(fault); } }).end().to(serviceURI); How to propagate a camel-cxf endpoint's request and response contextcxf client API provides a way to invoke the operation with request and response context. If you are using a camel-cxf endpoint producer to invoke the outside web service, you can set the request context and get response context with the following code:
CxfExchange exchange = (CxfExchange)template.send(getJaxwsEndpointUri(), new Processor() {
public void process(final Exchange exchange) {
final List<String> params = new ArrayList<String>();
params.add(TEST_MESSAGE);
// Set the request context to the inMessage
Map<String, Object> requestContext = new HashMap<String, Object>();
requestContext.put(BindingProvider.ENDPOINT_ADDRESS_PROPERTY, JAXWS_SERVER_ADDRESS);
exchange.getIn().setBody(params);
exchange.getIn().setHeader(Client.REQUEST_CONTEXT , requestContext);
exchange.getIn().setHeader(CxfConstants.OPERATION_NAME, GREET_ME_OPERATION);
}
});
org.apache.camel.Message out = exchange.getOut();
// The output is an object array, the first element of the array is the return value
Object\[\] output = out.getBody(Object\[\].class);
LOG.info("Received output text: " + output\[0\]);
// Get the response context form outMessage
Map<String, Object> responseContext = CastUtils.cast((Map)out.getHeader(Client.RESPONSE_CONTEXT));
assertNotNull(responseContext);
assertEquals("Get the wrong wsdl opertion name", "{http://apache.org/hello_world_soap_http}greetMe",
responseContext.get("javax.xml.ws.wsdl.operation").toString());
Attachment SupportPOJO Mode: Both SOAP with Attachment and MTOM are supported (see example in Payload Mode for enabling MTOM). However, SOAP with Attachment is not tested. Since attachments are marshalled and unmarshalled into POJOs, users typically do not need to deal with the attachment themself. Attachments are propagated to Camel message's attachments since 2.1. So, it is possible to retreive attachments by Camel Message API DataHandler Message.getAttachment(String id)
. Payload Mode: MTOM is supported since 2.1. Attachments can be retrieved by Camel Message APIs mentioned above. SOAP with Attachment (SwA) is supported and attachments can be retrieved since 2.5. SwA is the default (same as setting the CXF endpoint property "mtom_enabled" to false). To enable MTOM, set the CXF endpoint property "mtom_enabled" to true. (I believe you can only do it with Spring.) <cxf:cxfEndpoint id="routerEndpoint" address="http://localhost:${CXFTestSupport.port1}/CxfMtomRouterPayloadModeTest/jaxws-mtom/hello" wsdlURL="mtom.wsdl" serviceName="ns:HelloService" endpointName="ns:HelloPort" xmlns:ns="http://apache.org/camel/cxf/mtom_feature"> <cxf:properties> <!-- enable mtom by setting this property to true --> <entry key="mtom-enabled" value="true"/> <!-- set the camel-cxf endpoint data fromat to PAYLOAD mode --> <entry key="dataFormat" value="PAYLOAD"/> </cxf:properties> You can produce a Camel message with attachment to send to a CXF endpoint in Payload mode. Exchange exchange = context.createProducerTemplate().send("direct:testEndpoint", new Processor() { public void process(Exchange exchange) throws Exception { exchange.setPattern(ExchangePattern.InOut); List<Source> elements = new ArrayList<Source>(); elements.add(new DOMSource(DOMUtils.readXml(new StringReader(MtomTestHelper.REQ_MESSAGE)).getDocumentElement())); CxfPayload<SoapHeader> body = new CxfPayload<SoapHeader>(new ArrayList<SoapHeader>(), elements, null); exchange.getIn().setBody(body); exchange.getIn().addAttachment(MtomTestHelper.REQ_PHOTO_CID, new DataHandler(new ByteArrayDataSource(MtomTestHelper.REQ_PHOTO_DATA, "application/octet-stream"))); exchange.getIn().addAttachment(MtomTestHelper.REQ_IMAGE_CID, new DataHandler(new ByteArrayDataSource(MtomTestHelper.requestJpeg, "image/jpeg"))); } }); // process response CxfPayload<SoapHeader> out = exchange.getOut().getBody(CxfPayload.class); Assert.assertEquals(1, out.getBody().size()); Map<String, String> ns = new HashMap<String, String>(); ns.put("ns", MtomTestHelper.SERVICE_TYPES_NS); ns.put("xop", MtomTestHelper.XOP_NS); XPathUtils xu = new XPathUtils(ns); Element oute = new XmlConverter().toDOMElement(out.getBody().get(0)); Element ele = (Element)xu.getValue("//ns:DetailResponse/ns:photo/xop:Include", oute, XPathConstants.NODE); String photoId = ele.getAttribute("href").substring(4); // skip "cid:" ele = (Element)xu.getValue("//ns:DetailResponse/ns:image/xop:Include", oute, XPathConstants.NODE); String imageId = ele.getAttribute("href").substring(4); // skip "cid:" DataHandler dr = exchange.getOut().getAttachment(photoId); Assert.assertEquals("application/octet-stream", dr.getContentType()); MtomTestHelper.assertEquals(MtomTestHelper.RESP_PHOTO_DATA, IOUtils.readBytesFromStream(dr.getInputStream())); dr = exchange.getOut().getAttachment(imageId); Assert.assertEquals("image/jpeg", dr.getContentType()); BufferedImage image = ImageIO.read(dr.getInputStream()); Assert.assertEquals(560, image.getWidth()); Assert.assertEquals(300, image.getHeight()); You can also consume a Camel message received from a CXF endpoint in Payload mode. public static class MyProcessor implements Processor { @SuppressWarnings("unchecked") public void process(Exchange exchange) throws Exception { CxfPayload<SoapHeader> in = exchange.getIn().getBody(CxfPayload.class); // verify request Assert.assertEquals(1, in.getBody().size()); Map<String, String> ns = new HashMap<String, String>(); ns.put("ns", MtomTestHelper.SERVICE_TYPES_NS); ns.put("xop", MtomTestHelper.XOP_NS); XPathUtils xu = new XPathUtils(ns); Element body = new XmlConverter().toDOMElement(in.getBody().get(0)); Element ele = (Element)xu.getValue("//ns:Detail/ns:photo/xop:Include", body, XPathConstants.NODE); String photoId = ele.getAttribute("href").substring(4); // skip "cid:" Assert.assertEquals(MtomTestHelper.REQ_PHOTO_CID, photoId); ele = (Element)xu.getValue("//ns:Detail/ns:image/xop:Include", body, XPathConstants.NODE); String imageId = ele.getAttribute("href").substring(4); // skip "cid:" Assert.assertEquals(MtomTestHelper.REQ_IMAGE_CID, imageId); DataHandler dr = exchange.getIn().getAttachment(photoId); Assert.assertEquals("application/octet-stream", dr.getContentType()); MtomTestHelper.assertEquals(MtomTestHelper.REQ_PHOTO_DATA, IOUtils.readBytesFromStream(dr.getInputStream())); dr = exchange.getIn().getAttachment(imageId); Assert.assertEquals("image/jpeg", dr.getContentType()); MtomTestHelper.assertEquals(MtomTestHelper.requestJpeg, IOUtils.readBytesFromStream(dr.getInputStream())); // create response List<Source> elements = new ArrayList<Source>(); elements.add(new DOMSource(DOMUtils.readXml(new StringReader(MtomTestHelper.RESP_MESSAGE)).getDocumentElement())); CxfPayload<SoapHeader> sbody = new CxfPayload<SoapHeader>(new ArrayList<SoapHeader>(), elements, null); exchange.getOut().setBody(sbody); exchange.getOut().addAttachment(MtomTestHelper.RESP_PHOTO_CID, new DataHandler(new ByteArrayDataSource(MtomTestHelper.RESP_PHOTO_DATA, "application/octet-stream"))); exchange.getOut().addAttachment(MtomTestHelper.RESP_IMAGE_CID, new DataHandler(new ByteArrayDataSource(MtomTestHelper.responseJpeg, "image/jpeg"))); } } Message Mode: Attachments are not supported as it does not process the message at all. Streaming Support in PAYLOAD modeIn 2.8.2, the camel-cxf component now supports streaming of incoming messages when using PAYLOAD mode. Previously, the incoming messages would have been completely DOM parsed. For large messages, this is time consuming and uses a significant amount of memory. Starting in 2.8.2, the incoming messages can remain as a javax.xml.transform.Source while being routed and, if nothing modifies the payload, can then be directly streamed out to the target destination. For common "simple proxy" use cases (example: from("cxf:...").to("cxf:...")), this can provide very significant performance increases as well as significantly lowered memory requirements. However, there are cases where streaming may not be appropriate or desired. Due to the streaming nature, invalid incoming XML may not be caught until later in the processing chain. Also, certain actions may require the message to be DOM parsed anyway (like WS-Security or message tracing and such) in which case the advantages of the streaming is limited. At this point, there are two ways to control the streaming:
See AlsoCXF Bean Component (2.0 or later)The cxfbean: component allows other Camel endpoints to send exchange and invoke Web service bean objects. (Currently, it only supports JAXRS, JAXWS(new to camel2.1) annotated service bean.)
URI formatcxfbean:serviceBeanRef Where serviceBeanRef is a registry key to look up the service bean object. If serviceBeanRef references a List object, elements of the List are the service bean objects accepted by the endpoint. Options
Headers
A Working SampleThis sample shows how to create a route that starts a Jetty HTTP server. The route sends requests to a CXF Bean and invokes a JAXRS annotated service. First, create a route as follows. The from endpoint is a Jetty HTTP endpoint that is listening on port 9000. Notice that the matchOnUriPrefix option must be set to true because RESTful request URI will not match the endpoint's URI http://localhost:9000 exactly. <route> <from ref="ep1" /> <to uri="cxfbean:customerServiceBean" /> </route> The to endpoint is a CXF Bean with bean name customerServiceBean. The name will be looked up from the registry. Next, we make sure our service bean is available in Spring registry. We create a bean definition in the Spring configuration. In this example, we create a List of service beans (of one element). We could have created just a single bean without a List. <util:list id="customerServiceBean"> <bean class="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService" /> </util:list> <bean class="org.apache.camel.wsdl_first.PersonImpl" id="jaxwsBean" /> That's it. Once the route is started, the web service is ready for business. A HTTP client can make a request and receive response. CXFRS Component
The cxfrs: component provides integration with Apache CXF for connecting to JAX-RS services hosted in CXF. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-cxf</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
cxfrs://address?options
Where address represents the CXF endpoint's address cxfrs:bean:rsEndpoint Where rsEndpoint represents the spring bean's name which presents the CXFRS client or server For either style above, you can append options to the URI as follows: cxfrs:bean:cxfEndpoint?resourceClass=org.apache.camel.rs.Example Options
You can also configure the CXF REST endpoint through the spring configuration. Since there are lots of difference between the CXF REST client and CXF REST Server, we provide different configuration for them. How to configure the REST endpoint in CamelIn camel-cxf schema file, there are two elements for the REST endpoint definition. cxf:rsServer for REST consumer, cxf:rsClient for REST producer. <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cxf="http://camel.apache.org/schema/cxf" xmlns:jaxrs="http://cxf.apache.org/jaxrs" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/cxf http://camel.apache.org/schema/cxf/camel-cxf.xsd http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd "> <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"/> <!-- Defined the real JAXRS back end service --> <jaxrs:server id="restService" address="http://localhost:${CXFTestSupport.port2}/CxfRsRouterTest/rest" staticSubresourceResolution="true"> <jaxrs:serviceBeans> <ref bean="customerService"/> </jaxrs:serviceBeans> </jaxrs:server> <!-- bean id="jsonProvider" class="org.apache.cxf.jaxrs.provider.JSONProvider"/--> <bean id="customerService" class="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService" /> <!-- Defined the server endpoint to create the cxf-rs consumer --> <cxf:rsServer id="rsServer" address="http://localhost:${CXFTestSupport.port1}/CxfRsRouterTest/route" serviceClass="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService" loggingFeatureEnabled="true" loggingSizeLimit="20"/> <!-- Defined the client endpoint to create the cxf-rs consumer --> <cxf:rsClient id="rsClient" address="http://localhost:${CXFTestSupport.port2}/CxfRsRouterTest/rest" serviceClass="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService" loggingFeatureEnabled="true" /> <!-- The camel route context --> <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="cxfrs://bean://rsServer"/> <!-- We can remove this configure as the CXFRS producer is using the HttpAPI by default --> <setHeader headerName="CamelCxfRsUsingHttpAPI"> <constant>True</constant> </setHeader> <to uri="cxfrs://bean://rsClient"/> </route> </camelContext> </beans> How to consume the REST request in CamelCXF JAXRS front end implements the JAXRS(JSR311) API, so we can export the resources classes as a REST service. And we leverage the CXF Invoker API to turn a REST request into a normal Java object method invocation. Here is an example of a CXFRS route... private static final String CXF_RS_ENDPOINT_URI = "cxfrs://http://localhost:" + CXT + "/rest?resourceClasses=org.apache.camel.component.cxf.jaxrs.testbean.CustomerServiceResource"; protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { public void configure() { errorHandler(new NoErrorHandlerBuilder()); from(CXF_RS_ENDPOINT_URI).process(new Processor() { public void process(Exchange exchange) throws Exception { Message inMessage = exchange.getIn(); // Get the operation name from in message String operationName = inMessage.getHeader(CxfConstants.OPERATION_NAME, String.class); if ("getCustomer".equals(operationName)) { String httpMethod = inMessage.getHeader(Exchange.HTTP_METHOD, String.class); assertEquals("Get a wrong http method", "GET", httpMethod); String path = inMessage.getHeader(Exchange.HTTP_PATH, String.class); // The parameter of the invocation is stored in the body of in message String id = inMessage.getBody(String.class); if ("/customerservice/customers/126".equals(path)) { Customer customer = new Customer(); customer.setId(Long.parseLong(id)); customer.setName("Willem"); // We just put the response Object into the out message body exchange.getOut().setBody(customer); } else { if ("/customerservice/customers/400".equals(path)) { // We return the remote client IP address this time org.apache.cxf.message.Message cxfMessage = inMessage.getHeader(CxfConstants.CAMEL_CXF_MESSAGE, org.apache.cxf.message.Message.class); ServletRequest request = (ServletRequest) cxfMessage.get("HTTP.REQUEST"); String remoteAddress = request.getRemoteAddr(); Response r = Response.status(200).entity("The remoteAddress is " + remoteAddress).build(); exchange.getOut().setBody(r); return; } if ("/customerservice/customers/123".equals(path)) { // send a customer response back Response r = Response.status(200).entity("customer response back!").build(); exchange.getOut().setBody(r); return; } if ("/customerservice/customers/456".equals(path)) { Response r = Response.status(404).entity("Can't found the customer with uri " + path).build(); throw new WebApplicationException(r); } else { throw new RuntimeCamelException("Can't found the customer with uri " + path); } } } if ("updateCustomer".equals(operationName)) { assertEquals("Get a wrong customer message header", "header1;header2", inMessage.getHeader("test")); String httpMethod = inMessage.getHeader(Exchange.HTTP_METHOD, String.class); assertEquals("Get a wrong http method", "PUT", httpMethod); Customer customer = inMessage.getBody(Customer.class); assertNotNull("The customer should not be null.", customer); // Now you can do what you want on the customer object assertEquals("Get a wrong customer name.", "Mary", customer.getName()); // set the response back exchange.getOut().setBody(Response.ok().build()); } } }); } }; } And the corresponding resource class used to configure the endpoint...
@Path("/customerservice/") public class CustomerServiceResource { public CustomerServiceResource() { } @GET @Path("/customers/{id}/") public Customer getCustomer(@PathParam("id") String id) { return null; } @PUT @Path("/customers/") public Response updateCustomer(Customer customer) { return null; } } How to invoke the REST service through camel-cxfrs producerCXF JAXRS front end implements a proxy based client API, with this API you can invoke the remote REST service through a proxy. Here is an example Exchange exchange = template.send("direct://proxy", new Processor() { public void process(Exchange exchange) throws Exception { exchange.setPattern(ExchangePattern.InOut); Message inMessage = exchange.getIn(); setupDestinationURL(inMessage); // set the operation name inMessage.setHeader(CxfConstants.OPERATION_NAME, "getCustomer"); // using the proxy client API inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_USING_HTTP_API, Boolean.FALSE); // set the parameters , if you just have one parameter // camel will put this object into an Object[] itself inMessage.setBody("123"); } }); // get the response message Customer response = (Customer) exchange.getOut().getBody(); assertNotNull("The response should not be null ", response); assertEquals("Get a wrong customer id ", String.valueOf(response.getId()), "123"); assertEquals("Get a wrong customer name", response.getName(), "John"); assertEquals("Get a wrong response code", 200, exchange.getOut().getHeader(Exchange.HTTP_RESPONSE_CODE)); CXF JAXRS front end also provides a http centric client API, You can also invoke this API from camel-cxfrs producer. You need to specify the HTTP_PATH and Http method and let the the producer know to use the http centric client by using the URI option httpClientAPI or set the message header with CxfConstants.CAMEL_CXF_RS_USING_HTTP_API. You can turn the response object to the type class that you specify with CxfConstants.CAMEL_CXF_RS_RESPONSE_CLASS. Exchange exchange = template.send("direct://http", new Processor() { public void process(Exchange exchange) throws Exception { exchange.setPattern(ExchangePattern.InOut); Message inMessage = exchange.getIn(); setupDestinationURL(inMessage); // using the http central client API inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_USING_HTTP_API, Boolean.TRUE); // set the Http method inMessage.setHeader(Exchange.HTTP_METHOD, "GET"); // set the relative path inMessage.setHeader(Exchange.HTTP_PATH, "/customerservice/customers/123"); // Specify the response class , cxfrs will use InputStream as the response object type inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_RESPONSE_CLASS, Customer.class); // since we use the Get method, so we don't need to set the message body inMessage.setBody(null); } }); // get the response message Customer response = (Customer) exchange.getOut().getBody(); assertNotNull("The response should not be null ", response); assertEquals("Get a wrong customer id ", String.valueOf(response.getId()), "123"); assertEquals("Get a wrong customer name", response.getName(), "John"); assertEquals("Get a wrong response code", 200, exchange.getOut().getHeader(Exchange.HTTP_RESPONSE_CODE)); From Camel 2.1, we also support to specify the query parameters from cxfrs URI for the CXFRS http centric client. Exchange exchange = template.send("cxfrs://http://localhost:" + getPort2() + "/" + getClass().getSimpleName() + "/testQuery?httpClientAPI=true&q1=12&q2=13"
Map<String, String> queryMap = new LinkedHashMap<String, String>(); queryMap.put("q1", "new"); queryMap.put("q2", "world"); inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_QUERY_MAP, queryMap); DataSet ComponentTesting of distributed and asynchronous processing is notoriously difficult. The Mock, Test and DataSet endpoints work great with the Camel Testing Framework to simplify your unit and integration testing using Enterprise Integration Patterns and Camel's large range of Components together with the powerful Bean Integration.The DataSet component (available since 1.3.0) provides a mechanism to easily perform load & soak testing of your system. It works by allowing you to create DataSet instances both as a source of messages and as a way to assert that the data set is received. Camel will use the throughput logger when sending dataset's. URI formatdataset:name[?options] Where name is used to find the DataSet instance in the Registry Camel ships with a support implementation of org.apache.camel.component.dataset.DataSet, the org.apache.camel.component.dataset.DataSetSupport class, that can be used as a base for implementing your own DataSet. Camel also ships with a default implementation, the org.apache.camel.component.dataset.SimpleDataSet that can be used for testing. Options
You can append query options to the URI in the following format, ?option=value&option=value&... Configuring DataSetCamel will lookup in the Registry for a bean implementing the DataSet interface. So you can register your own DataSet as: <bean id="myDataSet" class="com.mycompany.MyDataSet"> <property name="size" value="100"/> </bean> ExampleFor example, to test that a set of messages are sent to a queue and then consumed from the queue without losing any messages: // send the dataset to a queue from("dataset:foo").to("activemq:SomeQueue"); // now lets test that the messages are consumed correctly from("activemq:SomeQueue").to("dataset:foo"); The above would look in the Registry to find the foo DataSet instance which is used to create the messages. Then you create a DataSet implementation, such as using the SimpleDataSet as described below, configuring things like how big the data set is and what the messages look like etc. Properties on SimpleDataSet
See AlsoDb4o ComponentAvailable as of Camel 2.5 The db4o: component allows you to work with db4o NoSQL database. The camel-db4o library is provided by the Camel Extra project which hosts all *GPL related components for Camel. Sending to the endpointSending POJO object to the db4o endpoint adds and saves object into the database. The body of the message is assumed to be a POJO that has to be saved into the db40 database store. Consuming from the endpointConsuming messages removes (or updates) POJO objects in the database. This allows you to use a Db4o datastore as a logical queue; consumers take messages from the queue and then delete them to logically remove them from the queue. If you do not wish to delete the object when it has been processed, you can specify consumeDelete=false on the URI. This will result in the POJO being processed each poll. URI formatdb4o:className[?options] You can append query options to the URI in the following format, ?option=value&option=value&... Options
See AlsoDirect ComponentThe direct: component provides direct, synchronous invocation of any consumers when a producer sends a message exchange.
URI formatdirect:someName[?options] Where someName can be any string to uniquely identify the endpoint Options
You can append query options to the URI in the following format, ?option=value&option=value&... SamplesIn the route below we use the direct component to link the two routes together: from("activemq:queue:order.in") .to("bean:orderServer?method=validate") .to("direct:processOrder"); from("direct:processOrder") .to("bean:orderService?method=process") .to("activemq:queue:order.out"); And the sample using spring DSL: <route> <from uri="activemq:queue:order.in"/> <to uri="bean:orderService?method=validate"/> <to uri="direct:processOrder"/> </route> <route> <from uri="direct:processOrder"/> <to uri="bean:orderService?method=process"/> <to uri="activemq:queue:order.out"/> </route> See also samples from the SEDA component, how they can be used together. See AlsoDNSAvailable as of Camel 2.7 This is an additional component for Camel to run DNS queries, using DNSJava. The component is a thin layer on top of DNSJava.
Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-dns</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatThe URI scheme for a DNS component is as follows
dns://operation
This component only supports producers. OptionsNone. Headers
ExamplesIP lookup
<route id="IPCheck">
<from uri="direct:start"/>
<to uri="dns:ip"/>
</route>
This looks up a domain's IP. For example, www.example.com resolves to 192.0.32.10. DNS lookup
<route id="IPCheck">
<from uri="direct:start"/>
<to uri="dns:lookup"/>
</route>
This returns a set of DNS records associated with a domain. DNS DigDig is a Unix command-line utility to run DNS queries.
<route id="IPCheck">
<from uri="direct:start"/>
<to uri="dns:dig"/>
</route>
The query must be provided in the header with key "dns.query". See AlsoEJB ComponentAvailable as of Camel 2.4 The ejb: component binds EJBs to Camel message exchanges. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ejb</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatejb:ejbName[?options] Where ejbName can be any string which is used to look up the EJB in the Application Server JNDI Registry Options
You can append query options to the URI in the following format, ?option=value&option=value&... The EJB component extends the Bean component in which most of the details from the Bean component applies to this component as well. Bean BindingHow bean methods to be invoked are chosen (if they are not specified explicitly through the method parameter) and how parameter values are constructed from the Message are all defined by the Bean Binding mechanism which is used throughout all of the various Bean Integration mechanisms in Camel. ExamplesIn the following examples we use the Greater EJB which is defined as follows: GreaterLocal.java public interface GreaterLocal { String hello(String name); String bye(String name); } And the implementation GreaterImpl.java @Stateless public class GreaterImpl implements GreaterLocal { public String hello(String name) { return "Hello " + name; } public String bye(String name) { return "Bye " + name; } } Using Java DSLIn this example we want to invoke the hello method on the EJB. Since this example is based on an unit test using Apache OpenEJB we have to set a JndiContext on the EJB component with the OpenEJB settings. @Override protected CamelContext createCamelContext() throws Exception { CamelContext answer = new DefaultCamelContext(); // enlist EJB component using the JndiContext EjbComponent ejb = answer.getComponent("ejb", EjbComponent.class); ejb.setContext(createEjbContext()); return answer; } private static Context createEjbContext() throws NamingException { // here we need to define our context factory to use OpenEJB for our testing Properties properties = new Properties(); properties.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.apache.openejb.client.LocalInitialContextFactory"); return new InitialContext(properties); } Then we are ready to use the EJB in the Camel route: from("direct:start") // invoke the greeter EJB using the local interface and invoke the hello method .to("ejb:GreaterImplLocal?method=hello") .to("mock:result");
Using Spring XMLAnd this is the same example using Spring XML instead: Again since this is based on an unit test we need to setup the EJB component: <!-- setup Camel EJB component --> <bean id="ejb" class="org.apache.camel.component.ejb.EjbComponent"> <property name="properties" ref="jndiProperties"/> </bean> <!-- use OpenEJB context factory --> <p:properties id="jndiProperties"> <prop key="java.naming.factory.initial">org.apache.openejb.client.LocalInitialContextFactory</prop> </p:properties> Before we are ready to use EJB in the Camel routes: <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <to uri="ejb:GreaterImplLocal?method=hello"/> <to uri="mock:result"/> </route> </camelContext> See AlsoEsperThe Esper component supports the Esper Library for Event Stream Processing. The camel-esper library is provided by the Camel Extra project which hosts all *GPL related components for Camel. URI formatesper:name[?options] When consuming from an Esper endpoint you must specify a pattern or eql statement to query the event stream. For example from("esper://cheese?pattern=every event=MyEvent(bar=5)"). to("activemq:Foo"); Options
You can append query options to the URI in the following format, ?option=value&option=value&... DemoThere is a demo which shows how to work with ActiveMQ, Camel and Esper in the Camel Extra project See AlsoEvent ComponentThe event: component provides access to the Spring ApplicationEvent objects. This allows you to publish ApplicationEvent objects to a Spring ApplicationContext or to consume them. You can then use Enterprise Integration Patterns to process them such as Message Filter. URI format
spring-event://default
If you use Camel 1.x then you may need to remove the // to get it working with the Spring event notification
spring-event:default
See AlsoFile Component - Camel 2.0 onwards
The File component provides access to file systems, allowing files to be processed by any other Camel Components or messages from other components to be saved to disk. URI formatfile:directoryName[?options] or
file://directoryName[?options]
Where directoryName represents the underlying file directory. You can append query options to the URI in the following format, ?option=value&option=value&...
URI OptionsCommon
Consumer
Default behavior for file consumer
Producer
Default behavior for file producer
Move and Delete operationsAny move or delete operations is executed after (post command) the routing has completed; so during processing of the Exchange the file is still located in the inbox folder. Lets illustrate this with an example:
from("file://inbox?move=.done").to("bean:handleOrder");
When a file is dropped in the inbox folder, the file consumer notices this and creates a new FileExchange that is routed to the handleOrder bean. The bean then processes the File object. At this point in time the file is still located in the inbox folder. After the bean completes, and thus the route is completed, the file consumer will perform the move operation and move the file to the .done sub-folder. The move and preMove options should be a directory name, which can be either relative or absolute. If relative, the directory is created as a sub-folder from within the folder where the file was consumed. By default, Camel will move consumed files to the .camel sub-folder relative to the directory where the file was consumed. If you want to delete the file after processing, the route should be:
from("file://inobox?delete=true").to("bean:handleOrder");
We have introduced a pre move operation to move files before they are processed. This allows you to mark which files have been scanned as they are moved to this sub folder before being processed.
from("file://inbox?preMove=inprogress").to("bean:handleOrder");
You can combine the pre move and the regular move:
from("file://inbox?preMove=inprogress&move=.done").to("bean:handleOrder");
So in this situation, the file is in the inprogress folder when being processed and after it's processed, it's moved to the .done folder. Fine grained control over Move and PreMove optionThe move and preMove option is Expression-based, so we have the full power of the File Language to do advanced configuration of the directory and name pattern. So if we want to move the file into a backup folder with today's date as the pattern, we can do:
move=backup/${date:now:yyyyMMdd}/${file:name}
About moveFailedThe moveFailed option allows you to move files that could not be processed succesfully to another location such as a error folder of your choice. For example to move the files in an error folder with a timestamp you can use moveFailed=/error/${file:name.noext}-${date:now:yyyyMMddHHmmssSSS}.${file:ext}. See more examples at File Language Message HeadersThe following headers are supported by this component: File producer only
File consumer only
Batch ConsumerThis component implements the Batch Consumer. Exchange Properties, file consumer onlyAs the file consumer is BatchConsumer it supports batching the files it polls. By batching it means that Camel will add some properties to the Exchange so you know the number of files polled the current index in that order.
This allows you for instance to know how many files exists in this batch and for instance let the Aggregator2 aggregate this number of files. Common gotchas with folder and filenamesWhen Camel is producing files (writing files) there are a few gotchas affecting how to set a filename of your choice. By default, Camel will use the message ID as the filename, and since the message ID is normally a unique generated ID, you will end up with filenames such as: ID-MACHINENAME-2443-1211718892437-1-0. If such a filename is not desired, then you must provide a filename in the CamelFileName message header. The constant, Exchange.FILE_NAME, can also be used. The sample code below produces files using the message ID as the filename: from("direct:report").to("file:target/reports"); To use report.txt as the filename you have to do: from("direct:report").setHeader(Exchange.FILE_NAME, constant("report.txt")).to( "file:target/reports"); ... the same as above, but with CamelFileName: from("direct:report").setHeader("CamelFileName", constant("report.txt")).to( "file:target/reports"); And a syntax where we set the filename on the endpoint with the fileName URI option. from("direct:report").to("file:target/reports/?fileName=report.txt"); Filename ExpressionFilename can be set either using the expression option or as a string-based File Language expression in the CamelFileName header. See the File Language for syntax and samples. Consuming files from folders where others drop files directlyBeware if you consume files from a folder where other applications write files directly. Take a look at the different readLock options to see what suits your use cases. The best approach is however to write to another folder and after the write move the file in the drop folder. However if you write files directly to the drop folder then the option changed could better detect whether a file is currently being written/copied as it uses a file changed algorithm to see whether the file size / modification changes over a period of time. The other read lock options rely on Java File API that sadly is not always very good at detecting this. You may also want to look at the doneFileName option, which uses a marker file (done) to signal when a file is done and ready to be consumed. Using done filesAvailable as of Camel 2.6 See also section writing done files below. If you want only to consume files when a done file exists, then you can use the doneFileName option on the endpoint.
from("file:bar?doneFileName=done");
Will only consume files from the bar folder, if a file name done exists in the same directory as the target files. Camel will automatically delete the done file when it's done consuming the files. However its more common to have one done file per target file. This means there is a 1:1 correlation. To do this you must use dynamic placeholders in the doneFileName option. Currently Camel supports the following two dynamic tokens: file:name and file:name.noext which must be enclosed in ${ }. The consumer only supports the static part of the done file name as either prefix or suffix (not both).
from("file:bar?doneFileName=${file:name}.done");
In this example only files will be polled if there exists a done file with the name file name.done. For example
You can also use a prefix for the done file, such as:
from("file:bar?doneFileName=ready-${file:name}");
Writing done filesAvailable as of Camel 2.6 After you have written af file you may want to write an additional done file as a kinda of marker, to indicate to others that the file is finished and has been written. To do that you can use the doneFileName option on the file producer endpoint.
.to("file:bar?doneFileName=done");
Will simply create a file named done in the same directory as the target file. However its more common to have one done file per target file. This means there is a 1:1 correlation. To do this you must use dynamic placeholders in the doneFileName option. Currently Camel supports the following two dynamic tokens: file:name and file:name.noext which must be enclosed in ${ }.
.to("file:bar?doneFileName=done-${file:name}");
Will for example create a file named done-foo.txt if the target file was foo.txt in the same directory as the target file.
.to("file:bar?doneFileName=${file:name}.done");
Will for example create a file named foo.txt.done if the target file was foo.txt in the same directory as the target file.
.to("file:bar?doneFileName=${file:name.noext}.done");
Will for example create a file named foo.done if the target file was foo.txt in the same directory as the target file. SamplesRead from a directory and write to another directory
from("file://inputdir/?delete=true").to("file://outputdir")
Listen on a directory and create a message for each file dropped there. Copy the contents to the outputdir and delete the file in the inputdir. Reading recursively from a directory and writing to another
from("file://inputdir/?recursive=true&delete=true").to("file://outputdir")
Listen on a directory and create a message for each file dropped there. Copy the contents to the outputdir and delete the file in the inputdir. Will scan recursively into sub-directories. Will lay out the files in the same directory structure in the outputdir as the inputdir, including any sub-directories. inputdir/foo.txt inputdir/sub/bar.txt Will result in the following output layout: outputdir/foo.txt outputdir/sub/bar.txt Using flattenIf you want to store the files in the outputdir directory in the same directory, disregarding the source directory layout (e.g. to flatten out the path), you just add the flatten=true option on the file producer side:
from("file://inputdir/?recursive=true&delete=true").to("file://outputdir?flatten=true")
Will result in the following output layout: outputdir/foo.txt outputdir/bar.txt Reading from a directory and the default move operationCamel will by default move any processed file into a .camel subdirectory in the directory the file was consumed from.
from("file://inputdir/?recursive=true&delete=true").to("file://outputdir")
Affects the layout as follows: inputdir/foo.txt inputdir/sub/bar.txt after inputdir/.camel/foo.txt inputdir/sub/.camel/bar.txt outputdir/foo.txt outputdir/sub/bar.txt Read from a directory and process the message in javafrom("file://inputdir/").process(new Processor() { public void process(Exchange exchange) throws Exception { Object body = exchange.getIn().getBody(); // do some business logic with the input body } }); The body will be a File object that points to the file that was just dropped into the inputdir directory. Read files from a directory and send the content to a jms queue
from("file://inputdir/").convertBodyTo(String.class).to("jms:test.queue")
By default the file endpoint sends a FileMessage which contains a File object as the body. If you send this directly to the JMS component the JMS message will only contain the File object but not the content. By converting the File to a String, the message will contain the file content which is probably what you want. The route above using Spring DSL: <route> <from uri="file://inputdir/"/> <convertBodyTo type="java.lang.String"/> <to uri="jms:test.queue"/> </route> Writing to filesCamel is of course also able to write files, i.e. produce files. In the sample below we receive some reports on the SEDA queue that we process before they are written to a directory. public void testToFile() throws Exception { MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedMessageCount(1); mock.expectedFileExists("target/test-reports/report.txt"); template.sendBody("direct:reports", "This is a great report"); assertMockEndpointsSatisfied(); } protected JndiRegistry createRegistry() throws Exception { // bind our processor in the registry with the given id JndiRegistry reg = super.createRegistry(); reg.bind("processReport", new ProcessReport()); return reg; } protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { public void configure() throws Exception { // the reports from the seda queue is processed by our processor // before they are written to files in the target/reports directory from("direct:reports").processRef("processReport").to("file://target/test-reports", "mock:result"); } }; } private static class ProcessReport implements Processor { public void process(Exchange exchange) throws Exception { String body = exchange.getIn().getBody(String.class); // do some business logic here // set the output to the file exchange.getOut().setBody(body); // set the output filename using java code logic, notice that this is done by setting // a special header property of the out exchange exchange.getOut().setHeader(Exchange.FILE_NAME, "report.txt"); } } Write to subdirectory using Exchange.FILE_NAMEUsing a single route, it is possible to write a file to any number of subdirectories. If you have a route setup as such:
<route>
<from uri="bean:myBean"/>
<to uri="file:/rootDirectory"/>
</route>
You can have myBean set the header Exchange.FILE_NAME to values such as: Exchange.FILE_NAME = hello.txt => /rootDirectory/hello.txt Exchange.FILE_NAME = foo/bye.txt => /rootDirectory/foo/bye.txt This allows you to have a single route to write files to multiple destinations. Using expression for filenamesIn this sample we want to move consumed files to a backup folder using today's date as a sub-folder name:
from("file://inbox?move=backup/${date:now:yyyyMMdd}/${file:name}").to("...");
See File Language for more samples. Avoiding reading the same file more than once (idempotent consumer)Camel supports Idempotent Consumer directly within the component so it will skip already processed files. This feature can be enabled by setting the idempotent=true option.
from("file://inbox?idempotent=true").to("...");
By default Camel uses a in memory based store for keeping track of consumed files, it uses a least recently used cache holding up to 1000 entries. You can plugin your own implementation of this store by using the idempotentRepository option using the # sign in the value to indicate it's a referring to a bean in the Registry with the specified id. <!-- define our store as a plain spring bean --> <bean id="myStore" class="com.mycompany.MyIdempotentStore"/> <route> <from uri="file://inbox?idempotent=true&idempotentRepository=#myStore"/> <to uri="bean:processInbox"/> </route> Camel will log at DEBUG level if it skips a file because it has been consumed before:
DEBUG FileConsumer is idempotent and the file has been consumed before. Will skip this file: target\idempotent\report.txt
Using a file based idempotent repositoryIn this section we will use the file based idempotent repository org.apache.camel.processor.idempotent.FileIdempotentRepository instead of the in-memory based that is used as default. We configure our repository using Spring XML creating our file idempotent repository and define our file consumer to use our repository with the idempotentRepository using # sign to indicate Registry lookup: <!-- this is our file based idempotent store configured to use the .filestore.dat as file --> <bean id="fileStore" class="org.apache.camel.processor.idempotent.FileIdempotentRepository"> <!-- the filename for the store --> <property name="fileStore" value="target/fileidempotent/.filestore.dat"/> <!-- the max filesize in bytes for the file. Camel will trunk and flush the cache if the file gets bigger --> <property name="maxFileStoreSize" value="512000"/> <!-- the number of elements in our store --> <property name="cacheSize" value="250"/> </bean> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="file://target/fileidempotent/?idempotent=true&idempotentRepository=#fileStore&move=done/${file:name}"/> <to uri="mock:result"/> </route> </camelContext> Using a JPA based idempotent repositoryIn this section we will use the JPA based idempotent repository instead of the in-memory based that is used as default. First we need a persistence-unit in META-INF/persistence.xml where we need to use the class org.apache.camel.processor.idempotent.jpa.MessageProcessed as model. <persistence-unit name="idempotentDb" transaction-type="RESOURCE_LOCAL"> <class>org.apache.camel.processor.idempotent.jpa.MessageProcessed</class> <properties> <property name="openjpa.ConnectionURL" value="jdbc:derby:target/idempotentTest;create=true"/> <property name="openjpa.ConnectionDriverName" value="org.apache.derby.jdbc.EmbeddedDriver"/> <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema"/> <property name="openjpa.Log" value="DefaultLevel=WARN, Tool=INFO"/> </properties> </persistence-unit> Then we need to setup a Spring jpaTemplate in the spring XML file: <!-- this is standard spring JPA configuration --> <bean id="jpaTemplate" class="org.springframework.orm.jpa.JpaTemplate"> <property name="entityManagerFactory" ref="entityManagerFactory"/> </bean> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"> <!-- we use idempotentDB as the persitence unit name defined in the persistence.xml file --> <property name="persistenceUnitName" value="idempotentDb"/> </bean> And finally we can create our JPA idempotent repository in the spring XML file as well: <!-- we define our jpa based idempotent repository we want to use in the file consumer --> <bean id="jpaStore" class="org.apache.camel.processor.idempotent.jpa.JpaMessageIdRepository"> <!-- Here we refer to the spring jpaTemplate --> <constructor-arg index="0" ref="jpaTemplate"/> <!-- This 2nd parameter is the name (= a cateogry name). You can have different repositories with different names --> <constructor-arg index="1" value="FileConsumer"/> </bean> And yes then we just need to refer to the jpaStore bean in the file consumer endpoint using the idempotentRepository using the # syntax option: <route> <from uri="file://inbox?idempotent=true&idempotentRepository=#jpaStore"/> <to uri="bean:processInbox"/> </route> Filter using org.apache.camel.component.file.GenericFileFilterCamel supports pluggable filtering strategies. You can then configure the endpoint with such a filter to skip certain files being processed. In the sample we have built our own filter that skips files starting with skip in the filename: public class MyFileFilter<T> implements GenericFileFilter<T> { public boolean accept(GenericFile<T> pathname) { // we dont accept any files starting with skip in the name return !pathname.getFileName().startsWith("skip"); } } And then we can configure our route using the filter attribute to reference our filter (using # notation) that we have defined in the spring XML file: <!-- define our sorter as a plain spring bean --> <bean id="myFilter" class="com.mycompany.MyFileSorter"/> <route> <from uri="file://inbox?filter=#myFilter"/> <to uri="bean:processInbox"/> </route> Filtering using ANT path matcher
The ANT path matcher is shipped out-of-the-box in the camel-spring jar. So you need to depend on camel-spring if you are using Maven. The file paths is matched with the following rules:
The sample below demonstrates how to use it: <camelContext xmlns="http://camel.apache.org/schema/spring"> <template id="camelTemplate"/> <!-- use myFilter as filter to allow setting ANT paths for which files to scan for --> <endpoint id="myFileEndpoint" uri="file://target/antpathmatcher?recursive=true&filter=#myAntFilter"/> <route> <from ref="myFileEndpoint"/> <to uri="mock:result"/> </route> </camelContext> <!-- we use the antpath file filter to use ant paths for includes and exlucde --> <bean id="myAntFilter" class="org.apache.camel.component.file.AntPathMatcherGenericFileFilter"> <!-- include and file in the subfolder that has day in the name --> <property name="includes" value="**/subfolder/**/*day*"/> <!-- exclude all files with bad in name or .xml files. Use comma to seperate multiple excludes --> <property name="excludes" value="**/*bad*,**/*.xml"/> </bean> Sorting using ComparatorCamel supports pluggable sorting strategies. This strategy it to use the build in java.util.Comparator in Java. You can then configure the endpoint with such a comparator and have Camel sort the files before being processed. In the sample we have built our own comparator that just sorts by file name: public class MyFileSorter<T> implements Comparator<GenericFile<T>> { public int compare(GenericFile<T> o1, GenericFile<T> o2) { return o1.getFileName().compareToIgnoreCase(o2.getFileName()); } } And then we can configure our route using the sorter option to reference to our sorter (mySorter) we have defined in the spring XML file: <!-- define our sorter as a plain spring bean --> <bean id="mySorter" class="com.mycompany.MyFileSorter"/> <route> <from uri="file://inbox?sorter=#mySorter"/> <to uri="bean:processInbox"/> </route>
Sorting using sortByCamel supports pluggable sorting strategies. This strategy it to use the File Language to configure the sorting. The sortBy option is configured as follows: sortBy=group 1;group 2;group 3;... Where each group is separated with semi colon. In the simple situations you just use one group, so a simple example could be: sortBy=file:name This will sort by file name, you can reverse the order by prefixing reverse: to the group, so the sorting is now Z..A: sortBy=reverse:file:name As we have the full power of File Language we can use some of the other parameters, so if we want to sort by file size we do: sortBy=file:length You can configure to ignore the case, using ignoreCase: for string comparison, so if you want to use file name sorting but to ignore the case then we do: sortBy=ignoreCase:file:name You can combine ignore case and reverse, however reverse must be specified first: sortBy=reverse:ignoreCase:file:name In the sample below we want to sort by last modified file, so we do: sortBy=file:modifed And then we want to group by name as a 2nd option so files with same modifcation is sorted by name: sortBy=file:modifed;file:name Now there is an issue here, can you spot it? Well the modified timestamp of the file is too fine as it will be in milliseconds, but what if we want to sort by date only and then subgroup by name? sortBy=date:file:yyyyMMdd;file:name Yeah, that is pretty powerful, oh by the way you can also use reverse per group, so we could reverse the file names: sortBy=date:file:yyyyMMdd;reverse:file:name Using GenericFileProcessStrategyThe option processStrategy can be used to use a custom GenericFileProcessStrategy that allows you to implement your own begin, commit and rollback logic. So by implementing our own GenericFileProcessStrategy we can implement this as:
Debug loggingThis component has log level TRACE that can be helpful if you have problems. See AlsoFlatpack ComponentThe Flatpack component supports fixed width and delimited file parsing via the FlatPack library. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-flatpack</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatflatpack:[delim|fixed]:flatPackConfig.pzmap.xml[?options] Or for a delimited file handler with no configuration file just use flatpack:someName[?options] You can append query options to the URI in the following format, ?option=value&option=value&... URI Options
Examples
Message HeadersCamel will store the following headers on the IN message:
Message BodyThe component delivers the data in the IN message as a org.apache.camel.component.flatpack.DataSetList object that has converters for java.util.Map or java.util.List. For example to get the firstname from the sample below: Map row = exchange.getIn().getBody(Map.class); String firstName = row.get("FIRSTNAME"); However, you can also always get it as a List (even for splitRows=true). The same example: List data = exchange.getIn().getBody(List.class); Map row = (Map)data.get(0); String firstName = row.get("FIRSTNAME"); Header and Trailer recordsIn Camel 1.5 onwards the header and trailer notions in Flatpack are supported. However, you must use fixed record IDs:
The example below illustrates this fact that we have a header and a trailer. You can omit one or both of them if not needed.
<RECORD id="header" startPosition="1" endPosition="3" indicator="HBT">
<COLUMN name="INDICATOR" length="3"/>
<COLUMN name="DATE" length="8"/>
</RECORD>
<COLUMN name="FIRSTNAME" length="35" />
<COLUMN name="LASTNAME" length="35" />
<COLUMN name="ADDRESS" length="100" />
<COLUMN name="CITY" length="100" />
<COLUMN name="STATE" length="2" />
<COLUMN name="ZIP" length="5" />
<RECORD id="trailer" startPosition="1" endPosition="3" indicator="FBT">
<COLUMN name="INDICATOR" length="3"/>
<COLUMN name="STATUS" length="7"/>
</RECORD>
Using the endpointA common use case is sending a file to this endpoint for further processing in a separate route. For example: <camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="file://someDirectory"/> <to uri="flatpack:foo"/> </route> <route> <from uri="flatpack:foo"/> ... </route> </camelContext> You can also convert the payload of each message created to a Map for easy Bean Integration Flatpack DataFormatThe Flatpack component ships with the Flatpack data format that can be used to format between fixed width or delimited text messages to a List of rows as Map.
Notice: The Flatpack library does currently not support header and trailers for the marshal operation. OptionsThe data format has the following options:
UsageTo use the data format, simply instantiate an instance and invoke the marhsal or unmarshal operation in the route builder: FlatpackDataFormat fp = new FlatpackDataFormat(); fp.setDefinition(new ClassPathResource("INVENTORY-Delimited.pzmap.xml")); ... from("file:order/in").unmarshal(df).to("seda:queue:neworder"); The sample above will read files from the order/in folder and unmarshal the input using the Flatpack configuration file INVENTORY-Delimited.pzmap.xml that configures the structure of the files. The result is a DataSetList object we store on the SEDA queue. FlatpackDataFormat df = new FlatpackDataFormat(); df.setDefinition(new ClassPathResource("PEOPLE-FixedLength.pzmap.xml")); df.setFixed(true); df.setIgnoreFirstRecord(false); from("seda:people").marshal(df).convertBodyTo(String.class).to("jms:queue:people"); In the code above we marshal the data from a Object representation as a List of rows as Maps. The rows as Map contains the column name as the key, and the the corresponding value. This structure can be created in Java code from e.g. a processor. We marshal the data according to the Flatpack format and convert the result as a String object and store it on a JMS queue. DependenciesTo use Flatpack in your camel routes you need to add the a dependency on camel-flatpack which implements this data format. If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-flatpack</artifactId> <version>1.5.0</version> </dependency> See AlsoFreeMarkerThe freemarker: component allows for processing a message using a FreeMarker template. This can be ideal when using Templating to generate responses for requests. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-freemarker</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatfreemarker:templateName[?options] Where templateName is the classpath-local URI of the template to invoke; or the complete URL of the remote template (eg: file://folder/myfile.ftl). You can append query options to the URI in the following format, ?option=value&option=value&... Options
HeadersHeaders set during the FreeMarker evaluation are returned to the message and added as headers. This provides a mechanism for the FreeMarker component to return values to the Message. An example: Set the header value of fruit in the FreeMarker template:
${request.setHeader('fruit', 'Apple')}
The header, fruit, is now accessible from the message.out.headers. FreeMarker ContextCamel will provide exchange information in the FreeMarker context (just a Map). The Exchange is transferred as:
Hot reloadingThe FreeMarker template resource is by default not hot reloadable for both file and classpath resources (expanded jar). If you set contentCache=false, then Camel will not cache the resource and hot reloading is thus enabled. This scenario can be used in development. Dynamic templatesCamel provides two headers by which you can define a different resource location for a template or the template content itself. If any of these headers is set then Camel uses this over the endpoint configured resource. This allows you to provide a dynamic template at runtime.
SamplesFor example you could use something like: from("activemq:My.Queue"). to("freemarker:com/acme/MyResponse.ftl"); To use a FreeMarker template to formulate a response for a message for InOut message exchanges (where there is a JMSReplyTo header). If you want to use InOnly and consume the message and send it to another destination you could use: from("activemq:My.Queue"). to("freemarker:com/acme/MyResponse.ftl"). to("activemq:Another.Queue"); And to disable the content cache, e.g. for development usage where the .ftl template should be hot reloaded: from("activemq:My.Queue"). to("freemarker:com/acme/MyResponse.ftl?contentCache=false"). to("activemq:Another.Queue"); And a file-based resource: from("activemq:My.Queue"). to("freemarker:file://myfolder/MyResponse.ftl?contentCache=false"). to("activemq:Another.Queue"); In Camel 2.1 it's possible to specify what template the component should use dynamically via a header, so for example: from("direct:in"). setHeader(FreemarkerConstants.FREEMARKER_RESOURCE_URI).constant("path/to/my/template.ftl"). to("freemarker:dummy"); The Email SampleIn this sample we want to use FreeMarker templating for an order confirmation email. The email template is laid out in FreeMarker as:
Dear ${headers.lastName}, ${headers.firstName}
Thanks for the order of ${headers.item}.
Regards Camel Riders Bookstore
${body}
And the java code: private Exchange createLetter() { Exchange exchange = context.getEndpoint("direct:a").createExchange(); Message msg = exchange.getIn(); msg.setHeader("firstName", "Claus"); msg.setHeader("lastName", "Ibsen"); msg.setHeader("item", "Camel in Action"); msg.setBody("PS: Next beer is on me, James"); return exchange; } @Test public void testFreemarkerLetter() throws Exception { MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedMessageCount(1); mock.expectedBodiesReceived("Dear Ibsen, Claus\n\nThanks for the order of Camel in Action." + "\n\nRegards Camel Riders Bookstore\nPS: Next beer is on me, James"); template.send("direct:a", createLetter()); mock.assertIsSatisfied(); } protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { public void configure() throws Exception { from("direct:a") .to("freemarker:org/apache/camel/component/freemarker/letter.ftl") .to("mock:result"); } }; } See AlsoFTP/SFTP/FTPS Component - Camel 2.0 onwardsThis component provides access to remote file systems over the FTP and SFTP protocols. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ftp</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
URI formatftp://[username@]hostname[:port]/directoryname[?options] sftp://[username@]hostname[:port]/directoryname[?options] ftps://[username@]hostname[:port]/directoryname[?options] Where directoryname represents the underlying directory. Can contain nested folders. If no username is provided, then anonymous login is attempted using no password. You can append query options to the URI in the following format, ?option=value&option=value&... This component uses two different libraries for the actual FTP work. FTP and FTPS uses Apache Commons Net while SFTP uses JCraft JSCH. The FTPS component is only available in Camel 2.2 or newer. URI OptionsThe options below are exclusive for the FTP2 component.
You can configure additional options on the ftpClient and ftpClientConfig from the URI directly by using the ftpClient. or ftpClientConfig. prefix. For example to set the setDataTimeout on the FTPClient to 30 seconds you can do:
from("ftp://foo@myserver?password=secret&ftpClient.dataTimeout=30000").to("bean:foo");
You can mix and match and have use both prefixes, for example to configure date format or timezones.
from("ftp://foo@myserver?password=secret&ftpClient.dataTimeout=30000&ftpClientConfig.serverLanguageCode=fr").to("bean:foo");
You can have as many of these options as you like. See the documentation of the Apache Commons FTP FTPClientConfig for possible options and more details. If you do not like having many and long configuration in the url you can refer to the ftpClient or ftpClientConfig to use by letting Camel lookup in the Registry for it. For example: <bean id="myConfig" class="org.apache.commons.net.ftp.FTPClientConfig"> <property name="lenientFutureDates" value="true"/> <property name="serverLanguageCode" value="fr"/> </bean> And then let Camel lookup this bean when you use the # notation in the url.
from("ftp://foo@myserver?password=secret&ftpClientConfig=#myConfig").to("bean:foo");
More URI options
Examplesftp://someone@someftpserver.com/public/upload/images/holiday2008?password=secret&binary=true
Default when consuming filesThe FTP consumer will by default leave the consumed files untouched on the remote FTP server. You have to configure it explicitly if you want it to delete the files or move them to another location. For example you can use delete=true to delete the files, or use move=.done to move the files into a hidden done sub directory. The regular File consumer is different as it will by default move files to a .camel sub directory. The reason Camel does not do this by default for the FTP consumer is that it may lack permissions by default to be able to move or delete files. limitationsThe option readLock can be used to force Camel not to consume files that is currently in the progress of being written. However, this option is turned off by default, as it requires that the user has write access. See the options table at File2 for more details about read locks. When moving files using move or preMove option the files are restricted to the FTP_ROOT folder. That prevents you from moving files outside the FTP area. If you want to move files to another area you can use soft links and move files into a soft linked folder. Message HeadersThe following message headers can be used to affect the behavior of the component
About timeoutsThe two set of libraries (see top) has different API for setting timeout. You can use the connectTimeout option for both of them to set a timeout in millis to establish a network connection. An individual soTimeout can also be set on the FTP/FTPS, which corresponds to using ftpClient.soTimeout. Notice SFTP will automatically use connectTimeout as its soTimeout. The timeout option only applies for FTP/FTSP as the data timeout, which corresponds to the ftpClient.dataTimeout value. All timeout values are in millis. Using Local Work DirectoryCamel supports consuming from remote FTP servers and downloading the files directly into a local work directory. This avoids reading the entire remote file content into memory as it is streamed directly into the local file using FileOutputStream. Camel will store to a local file with the same name as the remote file, though with .inprogress as extension while the file is being downloaded. Afterwards, the file is renamed to remove the .inprogress suffix. And finally, when the Exchange is complete the local file is deleted. So if you want to download files from a remote FTP server and store it as files then you need to route to a file endpoint such as:
from("ftp://someone@someserver.com?password=secret&localWorkDirectory=/tmp").to("file://inbox");
Stepwise changing directoriesCamel FTP can operate in two modes in terms of traversing directories when consuming files (eg downloading) or producing files (eg uploading)
You may want to pick either one depending on your situation and security issues. Some Camel end users can only download files if they use stepwise, while others can only download if they do not. At least you have the choice to pick (from Camel 2.6 onwards). In Came 2.0 - 2.5 there is only one mode and it is:
From Camel 2.6 onwards there is now an option stepwise you can use to control the behavior. Note that stepwise changing of directory will in most cases only work when the user is confined to it's home directory and when the home directory is reported as "/". The difference between the two of them is best illustrated with an example. Suppose we have the following directory structure on the remote FTP server we need to traverse and download files: / /one /one/two /one/two/sub-a /one/two/sub-b And that we have a file in each of sub-a (a.txt) and sub-b (b.txt) folder. Using stepwise=true (default mode)TYPE A 200 Type set to A PWD 257 "/" is current directory. CWD one 250 CWD successful. "/one" is current directory. CWD two 250 CWD successful. "/one/two" is current directory. SYST 215 UNIX emulated by FileZilla PORT 127,0,0,1,17,94 200 Port command successful LIST 150 Opening data channel for directory list. 226 Transfer OK CWD sub-a 250 CWD successful. "/one/two/sub-a" is current directory. PORT 127,0,0,1,17,95 200 Port command successful LIST 150 Opening data channel for directory list. 226 Transfer OK CDUP 200 CDUP successful. "/one/two" is current directory. CWD sub-b 250 CWD successful. "/one/two/sub-b" is current directory. PORT 127,0,0,1,17,96 200 Port command successful LIST 150 Opening data channel for directory list. 226 Transfer OK CDUP 200 CDUP successful. "/one/two" is current directory. CWD / 250 CWD successful. "/" is current directory. PWD 257 "/" is current directory. CWD one 250 CWD successful. "/one" is current directory. CWD two 250 CWD successful. "/one/two" is current directory. PORT 127,0,0,1,17,97 200 Port command successful RETR foo.txt 150 Opening data channel for file transfer. 226 Transfer OK CWD / 250 CWD successful. "/" is current directory. PWD 257 "/" is current directory. CWD one 250 CWD successful. "/one" is current directory. CWD two 250 CWD successful. "/one/two" is current directory. CWD sub-a 250 CWD successful. "/one/two/sub-a" is current directory. PORT 127,0,0,1,17,98 200 Port command successful RETR a.txt 150 Opening data channel for file transfer. 226 Transfer OK CWD / 250 CWD successful. "/" is current directory. PWD 257 "/" is current directory. CWD one 250 CWD successful. "/one" is current directory. CWD two 250 CWD successful. "/one/two" is current directory. CWD sub-b 250 CWD successful. "/one/two/sub-b" is current directory. PORT 127,0,0,1,17,99 200 Port command successful RETR b.txt 150 Opening data channel for file transfer. 226 Transfer OK CWD / 250 CWD successful. "/" is current directory. QUIT 221 Goodbye disconnected. As you can see when stepwise is enabled, it will traverse the directory structure using CD xxx. Using stepwise=false230 Logged on TYPE A 200 Type set to A SYST 215 UNIX emulated by FileZilla PORT 127,0,0,1,4,122 200 Port command successful LIST one/two 150 Opening data channel for directory list 226 Transfer OK PORT 127,0,0,1,4,123 200 Port command successful LIST one/two/sub-a 150 Opening data channel for directory list 226 Transfer OK PORT 127,0,0,1,4,124 200 Port command successful LIST one/two/sub-b 150 Opening data channel for directory list 226 Transfer OK PORT 127,0,0,1,4,125 200 Port command successful RETR one/two/foo.txt 150 Opening data channel for file transfer. 226 Transfer OK PORT 127,0,0,1,4,126 200 Port command successful RETR one/two/sub-a/a.txt 150 Opening data channel for file transfer. 226 Transfer OK PORT 127,0,0,1,4,127 200 Port command successful RETR one/two/sub-b/b.txt 150 Opening data channel for file transfer. 226 Transfer OK QUIT 221 Goodbye disconnected. As you can see when not using stepwise, there are no CD operation invoked at all. SamplesIn the sample below we set up Camel to download all the reports from the FTP server once every hour (60 min) as BINARY content and store it as files on the local file system. protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { public void configure() throws Exception { // we use a delay of 60 minutes (eg. once pr. hour we poll the FTP server long delay = 60 * 60 * 1000L; // from the given FTP server we poll (= download) all the files // from the public/reports folder as BINARY types and store this as files // in a local directory. Camel will use the filenames from the FTPServer // notice that the FTPConsumer properties must be prefixed with "consumer." in the URL // the delay parameter is from the FileConsumer component so we should use consumer.delay as // the URI parameter name. The FTP Component is an extension of the File Component. from("ftp://tiger:scott@localhost/public/reports?binary=true&consumer.delay=" + delay). to("file://target/test-reports"); } }; } And the route using Spring DSL: <route> <from uri="ftp://scott@localhost/public/reports?password=tiger&binary=true&delay=60000"/> <to uri="file://target/test-reports"/> </route> Consuming a remote FTPS server (implicit SSL) and client authentication
from("ftps://admin@localhost:2222/public/camel?password=admin&securityProtocol=SSL&isImplicit=true
&ftpClient.keyStore.file=./src/test/resources/server.jks
&ftpClient.keyStore.password=password&ftpClient.keyStore.keyPassword=password")
.to("bean:foo");
Consuming a remote FTPS server (explicit TLS) and a custom trust store configurationfrom("ftps://admin@localhost:2222/public/camel?password=admin&ftpClient.trustStore.file=./src/test/resources/server.jks&ftpClient.trustStore.password=password") .to("bean:foo"); Filter using org.apache.camel.component.file.GenericFileFilterCamel supports pluggable filtering strategies. This strategy it to use the build in org.apache.camel.component.file.GenericFileFilter in Java. You can then configure the endpoint with such a filter to skip certain filters before being processed. In the sample we have built our own filter that only accepts files starting with report in the filename. public class MyFileFilter<T> implements GenericFileFilter<T> { public boolean accept(GenericFile<T> file) { // we only want report files return file.getFileName().startsWith("report"); } } And then we can configure our route using the filter attribute to reference our filter (using # notation) that we have defined in the spring XML file: <!-- define our sorter as a plain spring bean --> <bean id="myFilter" class="com.mycompany.MyFileFilter"/> <route> <from uri="ftp://someuser@someftpserver.com?password=secret&filter=#myFilter"/> <to uri="bean:processInbox"/> </route> Filtering using ANT path matcherThe ANT path matcher is a filter that is shipped out-of-the-box in the camel-spring jar. So you need to depend on camel-spring if you are using Maven. The file paths are matched with the following rules:
The sample below demonstrates how to use it: <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <template id="camelTemplate"/> <!-- use myFilter as filter to allow setting ANT paths for which files to scan for --> <endpoint id="myFTPEndpoint" uri="ftp://admin@localhost:${SpringFileAntPathMatcherRemoteFileFilterTest.ftpPort}/antpath?password=admin&recursive=true&delay=10000&initialDelay=2000&filter=#myAntFilter"/> <route> <from ref="myFTPEndpoint"/> <to uri="mock:result"/> </route> </camelContext> <!-- we use the AntPathMatcherRemoteFileFilter to use ant paths for includes and exlucde --> <bean id="myAntFilter" class="org.apache.camel.component.file.AntPathMatcherGenericFileFilter"> <!-- include and file in the subfolder that has day in the name --> <property name="includes" value="**/subfolder/**/*day*"/> <!-- exclude all files with bad in name or .xml files. Use comma to seperate multiple excludes --> <property name="excludes" value="**/*bad*,**/*.xml"/> </bean> Debug loggingThis component has log level TRACE that can be helpful if you have problems. See AlsoCamel Components for Google App Engine
The Camel components for Google App Engine (GAE) are part of the camel-gae project and provide connectivity to GAE's cloud computing services. They make the GAE cloud computing environment accessible to applications via Camel interfaces. Following this pattern for other cloud computing environments could make it easier to port Camel applications from one cloud computing provider to another. The following table lists the cloud computing services provided by Google and the supporting Camel components. The documentation of each component can be found by following the link in the Camel Component column.
Camel contextSetting up a SpringCamelContext on Google App Engine differs between Camel 2.1 and higher versions. The problem is that usage of the Camel-specific Spring configuration XML schema from the http://camel.apache.org/schema/spring namespace requires JAXB and Camel 2.1 depends on a Google App Engine SDK version that doesn't support JAXB yet. This limitation has been removed since Camel 2.2. JMX must be disabled in any case because the javax.management package isn't on the App Engine JRE whitelist. Camel 2.1camel-gae 2.1 comes with the following CamelContext implementations.
Both disable JMX before startup. The GaeSpringCamelContext additionally provides setter methods adding route builders as shown in the next example. appctx.xml <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <bean id="camelContext" class="org.apache.camel.component.gae.context.GaeSpringCamelContext"> <property name="routeBuilder" ref="myRouteBuilder" /> </bean> <bean id="myRouteBuilder" class="org.example.MyRouteBuilder"> </bean> </beans> Alternatively, use the routeBuilders property of the GaeSpringCamelContext for setting a list of route builders. Using this approach, a SpringCamelContext can be configured on GAE without the need for JAXB. Camel 2.2 or higherWith Camel 2.2 or higher, applications can use the http://camel.apache.org/schema/spring namespace for configuring a SpringCamelContext but still need to disable JMX. Here's an example. appctx.xml <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://camel.apache.org/schema/spring" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <camel:camelContext id="camelContext"> <camel:jmxAgent id="agent" disabled="true" /> <camel:routeBuilder ref="myRouteBuilder"/> </camel:camelContext> <bean id="myRouteBuilder" class="org.example.MyRouteBuilder"> </bean> </beans> The web.xmlRunning Camel on GAE requires usage of the CamelHttpTransportServlet from camel-servlet. The following example shows how to configure this servlet together with a Spring application context XML file. web.xml <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation=" http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <servlet> <servlet-name>CamelServlet</servlet-name> <servlet-class>org.apache.camel.component.servlet.CamelHttpTransportServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>appctx.xml</param-value> </init-param> </servlet> <!-- Mapping used for external requests --> <servlet-mapping> <servlet-name>CamelServlet</servlet-name> <url-pattern>/camel/*</url-pattern> </servlet-mapping> <!-- Mapping used for web hooks accessed by task queueing service. --> <servlet-mapping> <servlet-name>CamelServlet</servlet-name> <url-pattern>/worker/*</url-pattern> </servlet-mapping> </web-app> The location of the Spring application context XML file is given by the contextConfigLocation init parameter. The appctx.xml file must be on the classpath. The servlet mapping makes the Camel application accessible under http://<appname>.appspot.com/camel/... when deployed to Google App Engine where <appname> must be replaced by a real GAE application name. The second servlet mapping is used internally by the task queueing service for background processing via web hooks. This mapping is relevant for the gtask component and is explained there in more detail. Hazelcast ComponentAvailable as of Camel 2.7 The hazelcast: component allows you to work with the Hazelcast distributed data grid / cache. Hazelcast is a in memory data grid, entirely written in Java (single jar). It offers a great palette of different data stores like map, multi map (same key, n values), queue, list and atomic number. The main reason to use Hazelcast is its simple cluster support. If you have enabled multicast on your network you can run a cluster with hundred nodes with no extra configuration. Hazelcast can simply configured to add additional features like n copies between nodes (default is 1), cache persistence, network configuration (if needed), near cache, enviction and so on. For more information consult the Hazelcast documentation on http://www.hazelcast.com/documentation.jsp. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-hazelcast</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formathazelcast:[ map | multimap | queue | seda | set | atomicvalue | instance]:cachename[?options]
Sections
Usage of Mapmap cache producer - to("hazelcast:map:foo")If you want to store a value in a map you can use the map cache producer. The map cache producer provides 5 operations (put, get, update, delete, query). For the first 4 you have to provide the operation inside the "hazelcast.operation.type" header variable. In Java DSL you can use the constants from org.apache.camel.component.hazelcast.HazelcastConstants. Header Variables for the request message:
You can call the samples with: template.sendBodyAndHeader("direct:[put|get|update|delete|query]", "my-foo", HazelcastConstants.OBJECT_ID, "4711"); Sample for put:Java DSL: from("direct:put") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PUT_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX); Spring DSL: <route> <from uri="direct:put" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>put</constant> </setHeader> <to uri="hazelcast:map:foo" /> </route> Sample for get:Java DSL: from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX) .to("seda:out"); Spring DSL: <route> <from uri="direct:get" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>get</constant> </setHeader> <to uri="hazelcast:map:foo" /> <to uri="seda:out" /> </route> Sample for update:Java DSL: from("direct:update") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.UPDATE_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX); Spring DSL: <route> <from uri="direct:update" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>update</constant> </setHeader> <to uri="hazelcast:map:foo" /> </route> Sample for delete:Java DSL: from("direct:delete") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DELETE_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX); Spring DSL: <route> <from uri="direct:delete" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>delete</constant> </setHeader> <to uri="hazelcast:map:foo" /> </route> Sample for queryJava DSL: from("direct:query") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.QUERY_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX) .to("seda:out"); Spring DSL: <route> <from uri="direct:query" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>query</constant> </setHeader> <to uri="hazelcast:map:foo" /> <to uri="seda:out" /> </route> For the query operation Hazelcast offers a SQL like syntax to query your distributed map. String q1 = "bar > 1000"; template.sendBodyAndHeader("direct:query", null, HazelcastConstants.QUERY, q1); map cache consumer - from("hazelcast:map:foo")Hazelcast provides event listeners on their data grid. If you want to be notified if a cache will be manipulated, you can use the map consumer. There're 4 events: put, update, delete and envict. The event type will be stored in the "hazelcast.listener.action" header variable. The map consumer provides some additional information inside these variables: Header Variables inside the response message:
The object value will be stored within put and update actions inside the message body. Here's a sample: fromF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX) .log("object...") .choice() .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED)) .log("...added") .to("mock:added") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ENVICTED)) .log("...envicted") .to("mock:envicted") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.UPDATED)) .log("...updated") .to("mock:updated") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED)) .log("...removed") .to("mock:removed") .otherwise() .log("fail!"); Usage of Multi Mapmultimap cache producer - to("hazelcast:multimap:foo")A multimap is a cache where you can store n values to one key. The multimap producer provides 4 operations (put, get, removevalue, delete). Header Variables for the request message:
You can call the samples with: template.sendBodyAndHeader("direct:[put|get|update|delete|query]", "my-foo", HazelcastConstants.OBJECT_ID, "4711"); Sample for put:Java DSL: from("direct:put") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PUT_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX); Spring DSL: <route> <from uri="direct:put" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>put</constant> </setHeader> <to uri="hazelcast:map:foo" /> </route> Sample for get:Java DSL: from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX) .to("seda:out"); Spring DSL: <route> <from uri="direct:get" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>get</constant> </setHeader> <to uri="hazelcast:map:foo" /> <to uri="seda:out" /> </route> Sample for update:Java DSL: from("direct:update") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.UPDATE_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX); Spring DSL: <route> <from uri="direct:update" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>update</constant> </setHeader> <to uri="hazelcast:map:foo" /> </route> Sample for delete:Java DSL: from("direct:delete") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DELETE_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX); Spring DSL: <route> <from uri="direct:delete" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>delete</constant> </setHeader> <to uri="hazelcast:map:foo" /> </route> Sample for queryJava DSL: from("direct:query") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.QUERY_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX) .to("seda:out"); Spring DSL: <route> <from uri="direct:query" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>query</constant> </setHeader> <to uri="hazelcast:map:foo" /> <to uri="seda:out" /> </route> For the query operation Hazelcast offers a SQL like syntax to query your distributed map. String q1 = "bar > 1000"; template.sendBodyAndHeader("direct:query", null, HazelcastConstants.QUERY, q1); map cache consumer - from("hazelcast:map:foo")Hazelcast provides event listeners on their data grid. If you want to be notified if a cache will be manipulated, you can use the map consumer. There're 4 events: put, update, delete and envict. The event type will be stored in the "hazelcast.listener.action" header variable. The map consumer provides some additional information inside these variables: Header Variables inside the response message:
The object value will be stored within put and update actions inside the message body. Here's a sample: fromF("hazelcast:%sfoo", HazelcastConstants.MAP_PREFIX) .log("object...") .choice() .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED)) .log("...added") .to("mock:added") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ENVICTED)) .log("...envicted") .to("mock:envicted") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.UPDATED)) .log("...updated") .to("mock:updated") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED)) .log("...removed") .to("mock:removed") .otherwise() .log("fail!"); Usage of Multi Mapmultimap cache producer - to("hazelcast:multimap:foo")A multimap is a cache where you can store n values to one key. The multimap producer provides 4 operations (put, get, removevalue, delete). Header Variables for the request message:
Sample for put:Java DSL: from("direct:put") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PUT_OPERATION)) .to(String.format("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX)); Spring DSL: <route> <from uri="direct:put" /> <log message="put.."/> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>put</constant> </setHeader> <to uri="hazelcast:multimap:foo" /> </route> Sample for removevalue:Java DSL: from("direct:removevalue") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.REMOVEVALUE_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX); Spring DSL: <route> <from uri="direct:removevalue" /> <log message="removevalue..."/> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>removevalue</constant> </setHeader> <to uri="hazelcast:multimap:foo" /> </route> To remove a value you have to provide the value you want to remove inside the message body. If you have a multimap object {key: "4711" values: { "my-foo", "my-bar"}} you have to put "my-foo" inside the message body to remove the "my-foo" value. Sample for get:Java DSL: from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX) .to("seda:out"); Spring DSL: <route> <from uri="direct:get" /> <log message="get.."/> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>get</constant> </setHeader> <to uri="hazelcast:multimap:foo" /> <to uri="seda:out" /> </route> Sample for delete:Java DSL: from("direct:delete") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DELETE_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX); Spring DSL: <route> <from uri="direct:delete" /> <log message="delete.."/> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>delete</constant> </setHeader> <to uri="hazelcast:multimap:foo" /> </route> you can call them in your test class with: template.sendBodyAndHeader("direct:[put|get|removevalue|delete]", "my-foo", HazelcastConstants.OBJECT_ID, "4711"); multimap cache consumer - from("hazelcast:multimap:foo")For the multimap cache this component provides the same listeners / variables as for the map cache consumer (except the update and enviction listener). The only difference is the multimap prefix inside the URI. Here is a sample: fromF("hazelcast:%sbar", HazelcastConstants.MULTIMAP_PREFIX) .log("object...") .choice() .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED)) .log("...added") .to("mock:added") //.when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ENVICTED)) // .log("...envicted") // .to("mock:envicted") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED)) .log("...removed") .to("mock:removed") .otherwise() .log("fail!"); Header Variables inside the response message:
Eviction will be added as feature, soon (this is a Hazelcast issue).
Usage of QueueQueue producer – to(“hazelcast:queue:foo”)The queue producer provides 6 operations (add, put, poll, peek, offer, removevalue). Sample for add:from("direct:add") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.ADD_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.QUEUE_PREFIX); Sample for put:from("direct:put") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PUT_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.QUEUE_PREFIX); Sample for poll:from("direct:poll") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.POLL_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.QUEUE_PREFIX); Sample for peek:from("direct:peek") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.PEEK_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.QUEUE_PREFIX); Sample for offer:from("direct:offer") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.OFFER_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.QUEUE_PREFIX); Sample for removevalue:from("direct:removevalue") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.REMOVEVALUE_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.QUEUE_PREFIX); Queue consumer – from(“hazelcast:queue:foo”)The queue consumer provides 2 operations (add, remove). fromF("hazelcast:%smm", HazelcastConstants.QUEUE_PREFIX) .log("object...") .choice() .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED)) .log("...added") .to("mock:added") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED)) .log("...removed") .to("mock:removed") .otherwise() .log("fail!"); Usage of ListList producer – to(“hazelcast:list:foo”)The list producer provides 4 operations (add, set, get, removevalue). Sample for add:from("direct:add") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.ADD_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.LIST_PREFIX); Sample for get:from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.LIST_PREFIX) .to("seda:out"); Sample for setvalue:from("direct:set") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.SETVALUE_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.LIST_PREFIX); Sample for removevalue:from("direct:removevalue") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.REMOVEVALUE_OPERATION)) .toF("hazelcast:%sbar", HazelcastConstants.LIST_PREFIX);
List consumer – from(“hazelcast:list:foo”)The list consumer provides 2 operations (add, remove). fromF("hazelcast:%smm", HazelcastConstants.LIST_PREFIX) .log("object...") .choice() .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED)) .log("...added") .to("mock:added") .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.REMOVED)) .log("...removed") .to("mock:removed") .otherwise() .log("fail!"); Usage of SEDASEDA component differs from the rest components provided. It implements a work-queue in order to support asynchronous SEDA architectures, similar to the core "SEDA" component. SEDA producer – to(“hazelcast:seda:foo”)The SEDA producer provides no operations. You only send data to the specified queue.
Java DSL : from("direct:foo") .to("hazelcast:seda:foo"); Spring DSL : <route> <from uri="direct:start" /> <to uri="hazelcast:seda:foo" /> </route> SEDA consumer – from(“hazelcast:seda:foo”)The SEDA consumer provides no operations. You only retrieve data from the specified queue. Java DSL : from("hazelcast:seda:foo") .to("mock:result"); Spring DSL: <route> <from uri="hazelcast:seda:foo" /> <to uri="mock:result" /> </route> Usage of Atomic Number
atomic number producer - to("hazelcast:atomicnumber:foo")An atomic number is an object that simply provides a grid wide number (long). The operations for this producer are setvalue (set the number with a given value), get, increase (+1), decrease (-1) and destroy. Header Variables for the request message:
Sample for set:Java DSL: from("direct:set") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.SETVALUE_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX); Spring DSL: <route> <from uri="direct:set" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>setvalue</constant> </setHeader> <to uri="hazelcast:atomicvalue:foo" /> </route> Provide the value to set inside the message body (here the value is 10): template.sendBody("direct:set", 10); Sample for get:Java DSL: from("direct:get") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.GET_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX); Spring DSL: <route> <from uri="direct:get" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>get</constant> </setHeader> <to uri="hazelcast:atomicvalue:foo" /> </route> You can get the number with long body = template.requestBody("direct:get", null, Long.class);. Sample for increment:Java DSL: from("direct:increment") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.INCREMENT_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX); Spring DSL: <route> <from uri="direct:increment" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>increment</constant> </setHeader> <to uri="hazelcast:atomicvalue:foo" /> </route> The actual value (after increment) will be provided inside the message body. Sample for decrement:Java DSL: from("direct:decrement") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DECREMENT_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX); Spring DSL: <route> <from uri="direct:decrement" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>decrement</constant> </setHeader> <to uri="hazelcast:atomicvalue:foo" /> </route> The actual value (after decrement) will be provided inside the message body. Sample for destroy
Java DSL: from("direct:destroy") .setHeader(HazelcastConstants.OPERATION, constant(HazelcastConstants.DESTROY_OPERATION)) .toF("hazelcast:%sfoo", HazelcastConstants.ATOMICNUMBER_PREFIX); Spring DSL: <route> <from uri="direct:destroy" /> <!-- If using version 2.8 and above set headerName to "CamelHazelcastOperationType" --> <setHeader headerName="hazelcast.operation.type"> <constant>destroy</constant> </setHeader> <to uri="hazelcast:atomicvalue:foo" /> </route> cluster support
instance consumer - from("hazelcast:instance:foo")Hazelcast makes sense in one single "server node", but it's extremly powerful in a clustered environment. The instance consumer fires if a new cache instance will join or leave the cluster. Here's a sample: fromF("hazelcast:%sfoo", HazelcastConstants.INSTANCE_PREFIX) .log("instance...") .choice() .when(header(HazelcastConstants.LISTENER_ACTION).isEqualTo(HazelcastConstants.ADDED)) .log("...added") .to("mock:added") .otherwise() .log("...removed") .to("mock:removed"); Each event provides the following information inside the message header: Header Variables inside the response message:
HDFS ComponentAvailable as of Camel 2.8 The hdfs component enables you to read and write messages from/to an HDFS file system. HDFS is the distributed file system at the heart of Hadoop. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-hadoop</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
hdfs://hostname[:port][/path][?options]
You can append query options to the URI in the following format, ?option=value&option=value&...
Options
KeyType and ValueType
BYTES is also used with everything else, for example, in Camel a file is sent around as an InputStream, int this case is written in a sequence file or a map file as a sequence of bytes. Splitting StrategyIn the current version of Hadoop opening a file in append mode is disabled since it's not enough reliable. So, for the moment, it's only possible to create new files. The Camel HDFS endpoint tries to solve this problem in this way:
where <ST> can be:
for example:
hdfs://localhost/tmp/simple-file?splitStrategy=IDLE:1000,BYTES:5
it means: a new file is created either when it has been idle for more than 1 second or if more than 5 bytes have been written. So, running hadoop fs -ls /tmp/simple-file you'll find the following files seg0, seg1, seg2, etc Using this component in OSGiThis component is fully functional in an OSGi environment however, it requires some actions from the user. Hadoop uses the thread context class loader in order to load resources. Usually, the thread context classloader will be the bundle class loader of the bundle that contains the routes. So, the default configuration files need to be visible from the bundle class loader. A typical way to deal with it is to keep a copy of core-default.xml in your bundle root. That file can be found in the hadoop-common.jar. Hibernate ComponentThe hibernate: component allows you to work with databases using Hibernate as the object relational mapping technology to map POJOs to database tables. The camel-hibernate library is provided by the Camel Extra project which hosts all *GPL related components for Camel.
Sending to the endpointSending POJOs to the hibernate endpoint inserts entities into the database. The body of the message is assumed to be an entity bean that you have mapped to a relational table using the hibernate .hbm.xml files. If the body does not contain an entity bean, use a Message Translator in front of the endpoint to perform the necessary conversion first. Consuming from the endpointConsuming messages removes (or updates) entities in the database. This allows you to use a database table as a logical queue; consumers take messages from the queue and then delete/update them to logically remove them from the queue. If you do not wish to delete the entity when it has been processed, you can specify consumeDelete=false on the URI. This will result in the entity being processed each poll. If you would rather perform some update on the entity to mark it as processed (such as to exclude it from a future query) then you can annotate a method with @Consumed which will be invoked on your entity bean when the entity bean is consumed. URI formathibernate:[entityClassName][?options] For sending to the endpoint, the entityClassName is optional. If specified it is used to help use the Type Conversion to ensure the body is of the correct type. For consuming the entityClassName is mandatory. You can append query options to the URI in the following format, ?option=value&option=value&... Options
See AlsoHL7 ComponentThe hl7 component is used for working with the HL7 MLLP protocol and the HL7 model using the HAPI library. This component supports the following:
Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-hl7</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> HL7 MLLP protocolHL7 is often used with the HL7 MLLP protocol that is a text based TCP socket based protocol. This component ships with a Mina Codec that conforms to the MLLP protocol so you can easily expose a HL7 listener that accepts HL7 requests over the TCP transport. To expose a HL7 listener service we reuse the existing camel-mina component where we just use the HL7MLLPCodec as codec. The HL7 MLLP codec has the following options:
Exposing a HL7 listenerIn our Spring XML file, we configure an endpoint to listen for HL7 requests using TCP:
<endpoint id="hl7listener" uri="mina:tcp://localhost:8888?sync=true&codec=#hl7codec"/>
Notice we configure it to use camel-mina with TCP on the localhost on port 8888. We use sync=true to indicate that this listener is synchronous and therefore will return a HL7 response to the caller. Then we setup mina to use our HL7 codec with codec=#hl7codec. Notice that hl7codec is just a Spring bean ID, so we could have named it mygreatcodecforhl7 or whatever. The codec is also set up in the Spring XML file:
<bean id="hl7codec" class="org.apache.camel.component.hl7.HL7MLLPCodec">
<property name="charset" value="iso-8859-1"/>
</bean>
And here we configure the charset encoding to use, and iso-8859-1 is commonly used. The endpoint hl7listener can then be used in a route as a consumer, as this java DSL example illustrates:
from("hl7socket").to("patientLookupService");
This is a very simple route that will listen for HL7 and route it to a service named patientLookupService that is also a Spring bean ID we have configured in the Spring XML as:
<bean id="patientLookupService" class="com.mycompany.healtcare.service.PatientLookupService"/>
And another powerful feature of Camel is that we can have our busines logic in POJO classes that is not at all tied to Camel as shown here: public class PatientLookupService { public Message lookupPatient(Message input) throws HL7Exception { QRD qrd = (QRD)input.get("QRD"); String patientId = qrd.getWhoSubjectFilter(0).getIDNumber().getValue(); // find patient data based on the patient id and create a HL7 model object with the response Message response = ... create and set response data return response } Notice that this class is just using imports from the HAPI library and none from Camel. HL7 Model using java.lang.StringThe HL7MLLP codec uses plain String as data format. And Camel uses Type Converter to convert from/to strings to the HAPI HL7 model objects. However, you can use the plain String objects if you prefer, for instance if you need to parse the data yourself. See samples for such an example. HL7 Model using HAPIThe HL7 model is Java objects from the HAPI library. Using this library, we can encode and decode from the EDI format (ER7) that is mostly used with HL7. The ER7 sample below is a request to lookup a patient with the patient ID, 0101701234. MSH|^~\\&|MYSENDER|MYRECEIVER|MYAPPLICATION||200612211200||QRY^A19|1234|P|2.4 QRD|200612211200|R|I|GetPatient|||1^RD|0101701234|DEM|| Using the HL7 model we can work with the data as a ca.uhn.hl7v2.model.Message.Message object. Message msg = exchange.getIn().getBody(Message.class); QRD qrd = (QRD)msg.get("QRD"); String patientId = qrd.getWhoSubjectFilter(0).getIDNumber().getValue(); Camel has built-in type converters, so when this operation is invoked: Message msg = exchange.getIn().getBody(Message.class); Camel will convert the received HL7 data from String to Message. This is powerful when combined with the HL7 listener, then you as the end-user don't have to work with byte[], String or any other simple object formats. You can just use the HAPI HL7 model objects. HL7 DataFormatThe HL7 component ships with a HL7 data format that can be used to format between String and HL7 model objects.
To use the data format, simply instantiate an instance and invoke the marhsal or unmarshl operation in the route builder: DataFormat hl7 = new HL7DataFormat(); ... from("direct:hl7in").marshal(hl7).to("jms:queue:hl7out"); In the sample above, the HL7 is marshalled from a HAPI Message object to a byte stream and put on a JMS queue. DataFormat hl7 = new HL7DataFormat(); ... from("jms:queue:hl7out").unmarshal(hl7).to("patientLookupService"); Here we unmarshal the byte stream into a HAPI Message object that is passed to our patient lookup service. Notice there is a shorthand syntax in Camel for well-known data formats that is commonly used. from("direct:hl7in").marshal().hl7().to("jms:queue:hl7out"); from("jms:queue:hl7out").unmarshal().hl7().to("patientLookupService"); Message HeadersThe unmarshal operation adds these MSH fields as headers on the Camel message: Camel 1.x
Camel 2.0
All headers are String types. If a header value is missing, its value is null. OptionsThe HL7 Data Format supports the following options:
DependenciesTo use HL7 in your camel routes you need to add a dependency on camel-hl7, which implements this data format. If you use Maven, you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions). <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-hl7</artifactId> <version>2.2.0</version> </dependency> Since HAPI 0.6, the library has been split into a base library and several structures libraries, one for each HL7v2 message version:
By default camel-hl7 only references the HAPI base library. Applications are responsible for including structures libraries themselves. For example, if a application works with HL7v2 message versions 2.4 and 2.5 then the following dependencies must be added: <dependency> <groupId>ca.uhn.hapi</groupId> <artifactId>hapi-structures-v24</artifactId> <version>1.0</version> </dependency> <dependency> <groupId>ca.uhn.hapi</groupId> <artifactId>hapi-structures-v25</artifactId> <version>1.0</version> </dependency> OSGiAn OSGi bundle containing the base library, all structures libraries and required dependencies (on the bundle classpath) can be downloaded from the HAPI Maven repository as well. <dependency> <groupId>ca.uhn.hapi</groupId> <artifactId>hapi-osgi-base</artifactId> <version>1.0.1</version> </dependency> SamplesIn the following example we send a HL7 request to a HL7 listener and retrieves a response. We use plain String types in this example: String line1 = "MSH|^~\\&|MYSENDER|MYRECEIVER|MYAPPLICATION||200612211200||QRY^A19|1234|P|2.4"; String line2 = "QRD|200612211200|R|I|GetPatient|||1^RD|0101701234|DEM||"; StringBuilder in = new StringBuilder(); in.append(line1); in.append("\n"); in.append(line2); String out = (String)template.requestBody("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec", in.toString()); In the next sample, we want to route HL7 requests from our HL7 listener to our business logic. We have our business logic in a plain POJO that we have registered in the registry as hl7service = for instance using Spring and letting the bean id = hl7service. Our business logic is a plain POJO only using the HAPI library so we have these operations defined: public class MyHL7BusinessLogic { // This is a plain POJO that has NO imports whatsoever on Apache Camel. // its a plain POJO only importing the HAPI library so we can much easier work with the HL7 format. public Message handleA19(Message msg) throws Exception { // here you can have your business logic for A19 messages assertTrue(msg instanceof QRY_A19); // just return the same dummy response return createADR19Message(); } public Message handleA01(Message msg) throws Exception { // here you can have your business logic for A01 messages assertTrue(msg instanceof ADT_A01); // just return the same dummy response return createADT01Message(); } } Then we set up the Camel routes using the RouteBuilder as follows: DataFormat hl7 = new HL7DataFormat(); // we setup or HL7 listener on port 8888 (using the hl7codec) and in sync mode so we can return a response from("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec") // we use the HL7 data format to unmarshal from HL7 stream to the HAPI Message model // this ensures that the camel message has been enriched with hl7 specific headers to // make the routing much easier (see below) .unmarshal(hl7) // using choice as the content base router .choice() // where we choose that A19 queries invoke the handleA19 method on our hl7service bean .when(header("CamelHL7TriggerEvent").isEqualTo("A19")) .beanRef("hl7service", "handleA19") .to("mock:a19") // and A01 should invoke the handleA01 method on our hl7service bean .when(header("CamelHL7TriggerEvent").isEqualTo("A01")).to("mock:a01") .beanRef("hl7service", "handleA01") .to("mock:a19") // other types should go to mock:unknown .otherwise() .to("mock:unknown") // end choice block .end() // marhsal response back .marshal(hl7); Notice that we use the HL7 DataFormat to enrich our Camel Message with the MSH fields preconfigued on the Camel Message. This lets us much more easily define our routes using the fluent builders. Sample using plain String objectsIn this sample we use plain String objects as the data format, that we send, process and receive. As the sample is part of a unit test, there is some code for assertions, but you should be able to understand what happens. First we send the plain string, Hello World, to the HL7MLLPCodec and receive the response as a plain string, Bye World. MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedBodiesReceived("Bye World"); // send plain hello world as String Object out = template.requestBody("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec", "Hello World"); assertMockEndpointsSatisfied(); // and the response is also just plain String assertEquals("Bye World", out); Here we process the incoming data as plain String and send the response also as plain String: from("mina:tcp://127.0.0.1:8888?sync=true&codec=#hl7codec") .process(new Processor() { public void process(Exchange exchange) throws Exception { // use plain String as message format String body = exchange.getIn().getBody(String.class); assertEquals("Hello World", body); // return the response as plain string exchange.getOut().setBody("Bye World"); } }) .to("mock:result"); See AlsoHTTP ComponentThe http: component provides HTTP based endpoints for consuming external HTTP resources (as a client to call external servers using HTTP). Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-http</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formathttp:hostname[:port][/resourceUri][?param1=value1][¶m2=value2] Will by default use port 80 for HTTP and 443 for HTTPS.
ExamplesCall the url with the body using POST and return response as out message. If body is null call URL using GET and return response as out message
You can override the HTTP endpoint URI by adding a header. Camel will call the http://newhost. This is very handy for e.g. REST urls.
URI parameters can either be set directly on the endpoint URI or as a header
Set the HTTP request method to POST
HttpEndpoint Options
Authentication and ProxyThe following authentication options can also be set on the HttpEndpoint:
When using authentication you must provide the choice of method for the authMethod or authProxyMethod options. The HTTP component uses convention over configuration which means that if you have not explicit set a authMethodPriority then it will fallback and use the select(ed) authMethod as priority as well. So if you use authMethod.Basic then the auhtMethodPriority will be Basic only. HttpComponent Options
HttpConfiguration contains all the options listed in the table above under the section HttpConfiguration - Setting Authentication and Proxy. Message Headers
The header name above are constants. For the spring DSL you have to use the value of the constant instead of the name. Message BodyCamel will store the HTTP response from the external server on the OUT body. All headers from the IN message will be copied to the OUT message, so headers are preserved during routing. Additionally Camel will add the HTTP response headers as well to the OUT message headers. Response codeCamel will handle according to the HTTP response code:
HttpOperationFailedExceptionThis exception contains the following information:
Calling using GET or POSTThe following algorithm is used to determine if either GET or POST HTTP method should be used: How to get access to HttpServletRequest and HttpServletResponseYou can get access to these two using the Camel type converter system using HttpServletRequest request = exchange.getIn().getBody(HttpServletRequest.class); HttpServletRequest response = exchange.getIn().getBody(HttpServletResponse.class); Using client tineout - SO_TIMEOUTSee the unit test in this link More ExamplesConfiguring a Proxy
There is also support for proxy authentication via the proxyUsername and proxyPassword options. Using proxy settings outside of URI
Options on Endpoint will override options on the context. Configuring charsetIf you are using POST to send data you can configure the charset
setProperty(Exchange.CHARSET_NAME, "iso-8859-1");
Sample with scheduled pollThe sample polls the Google homepage every 10 seconds and write the page to the file message.html: from("timer://foo?fixedRate=true&delay=0&period=10000") .to("http://www.google.com") .setHeader(FileComponent.HEADER_FILE_NAME, "message.html").to("file:target/google"); Getting the Response CodeYou can get the HTTP response code from the HTTP component by getting the value from the Out message header with HttpProducer.HTTP_RESPONSE_CODE. Exchange exchange = template.send("http://www.google.com/search", new Processor() { public void process(Exchange exchange) throws Exception { exchange.getIn().setHeader(Exchange.HTTP_QUERY, constant("hl=en&q=activemq")); } }); Message out = exchange.getOut(); int responseCode = out.getHeader(HttpProducer.HTTP_RESPONSE_CODE, Integer.class); Using throwExceptionOnFailure=false to get any response backIn the route below we want to route a message that we enrich with data returned from a remote HTTP call. As we want any response from the remote server, we set the throwExceptionOnFailure option to false so we get any response in the AggregationStrategy. As the code is based on a unit test that simulates a HTTP status code 404, there is some assertion code etc. // We set throwExceptionOnFailure to false to let Camel return any response from the remove HTTP server without thrown // HttpOperationFailedException in case of failures. // This allows us to handle all responses in the aggregation strategy where we can check the HTTP response code // and decide what to do. As this is based on an unit test we assert the code is 404 from("direct:start").enrich("http://localhost:{{port}}/myserver?throwExceptionOnFailure=false&user=Camel", new AggregationStrategy() { public Exchange aggregate(Exchange original, Exchange resource) { // get the response code Integer code = resource.getIn().getHeader(Exchange.HTTP_RESPONSE_CODE, Integer.class); assertEquals(404, code.intValue()); return resource; } }).to("mock:result"); // this is our jetty server where we simulate the 404 from("jetty://http://localhost:{{port}}/myserver") .process(new Processor() { public void process(Exchange exchange) throws Exception { exchange.getOut().setBody("Page not found"); exchange.getOut().setHeader(Exchange.HTTP_RESPONSE_CODE, 404); } }); Disabling CookiesTo disable cookies you can set the HTTP Client to ignore cookies by adding this URI option: Advanced UsageIf you need more control over the HTTP producer you should use the HttpComponent where you can set various classes to give you custom behavior. Setting MaxConnectionsPerHostThe HTTP Component has a org.apache.commons.httpclient.HttpConnectionManager where you can configure various global configuration for the given component. First, we define the http component in Spring XML. Yes, we use the same scheme name, http, because otherwise Camel will auto-discover and create the component with default settings. What we need is to overrule this so we can set our options. In the sample below we set the max connection to 5 instead of the default of 2. <bean id="http" class="org.apache.camel.component.http.HttpComponent"> <property name="camelContext" ref="camel"/> <property name="httpConnectionManager" ref="myHttpConnectionManager"/> </bean> <bean id="myHttpConnectionManager" class="org.apache.commons.httpclient.MultiThreadedHttpConnectionManager"> <property name="params" ref="myHttpConnectionManagerParams"/> </bean> <bean id="myHttpConnectionManagerParams" class="org.apache.commons.httpclient.params.HttpConnectionManagerParams"> <property name="defaultMaxConnectionsPerHost" value="5"/> </bean> And then we can just use it as we normally do in our routes: <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring" trace="true"> <route> <from uri="direct:start"/> <to uri="http://www.google.com"/> <to uri="mock:result"/> </route> </camelContext> Using preemptive authenticationAn end user reported that he had problem with authenticating with HTTPS. The problem was eventually resolved when he discovered the HTTPS server did not return a HTTP code 401 Authorization Required. The solution was to set the following URI option: httpClient.authenticationPreemptive=true Accepting self signed certificates from remote serverSee this link from a mailing list discussion with some code to outline how to do this with the Apache Commons HTTP API. Setting up SSL for HTTP ClientUsing the JSSE Configuration UtilityAs of Camel 2.8, the HTTP4 component supports SSL/TLS configuration through the Camel JSSE Configuration Utility. This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the HTTP4 component. The version of the Apache HTTP client used in this component resolves SSL/TLS information from a global "protocol" registry. This component provides an implementation, org.apache.camel.component.http.SSLContextParametersSecureProtocolSocketFactory, of the HTTP client's protocol socket factory in order to support the use of the Camel JSSE Configuration utility. The following example demonstrates how to configure the protocol registry and use the registered protocol information in a route. KeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); ProtocolSocketFactory factory = new SSLContextParametersSecureProtocolSocketFactory(scp); Protocol.registerProtocol("https", new Protocol( "https", factory, 443)); from("direct:start") .to("https://mail.google.com/mail/").to("mock:results"); Configuring Apache HTTP Client DirectlyBasically camel-http component is built on the top of Apache HTTP client, and you can implement a custom org.apache.camel.component.http.HttpClientConfigurer to do some configuration on the http client if you need full control of it. However if you just want to specify the keystore and truststore you can do this with Apache HTTP HttpClientConfigurer, for example: Protocol authhttps = new Protocol("https", new AuthSSLProtocolSocketFactory( new URL("file:my.keystore"), "mypassword", new URL("file:my.truststore"), "mypassword"), 443); Protocol.registerProtocol("https", authhttps); And then you need to create a class that implements HttpClientConfigurer, and registers https protocol providing a keystore or truststore per example above. Then, from your camel route builder class you can hook it up like so: HttpComponent httpComponent = getContext().getComponent("http", HttpComponent.class); httpComponent.setHttpClientConfigurer(new MyHttpClientConfigurer()); If you are doing this using the Spring DSL, you can specify your HttpClientConfigurer using the URI. For example: <bean id="myHttpClientConfigurer" class="my.https.HttpClientConfigurer"> </bean> <to uri="https://myhostname.com:443/myURL?httpClientConfigurerRef=myHttpClientConfigurer"/> As long as you implement the HttpClientConfigurer and configure your keystore and truststore as described above, it will work fine. See AlsoiBATISThe ibatis: component allows you to query, poll, insert, update and delete data in a relational database using Apache iBATIS. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ibatis</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatibatis:statementName[?options] Where statementName is the name in the iBATIS XML configuration file which maps to the query, insert, update or delete operation you wish to evaluate. You can append query options to the URI in the following format, ?option=value&option=value&... This component will by default load the iBatis SqlMapConfig file from the root of the classpath and expected named as SqlMapConfig.xml. Options
Message HeadersCamel will populate the result message, either IN or OUT with a header with the operationName used:
Message BodyCamel 1.6.1: The response from iBatis will be set as OUT body SamplesFor example if you wish to consume beans from a JMS queue and insert them into a database you could do the following: from("activemq:queue:newAccount"). to("ibatis:insertAccount?statementType=Insert"); Notice we have to specify the statementType, as we need to instruct Camel which SqlMapClient operation to invoke. Where insertAccount is the iBatis ID in the SQL map file: <!-- Insert example, using the Account parameter class --> <insert id="insertAccount" parameterClass="Account"> insert into ACCOUNT ( ACC_ID, ACC_FIRST_NAME, ACC_LAST_NAME, ACC_EMAIL ) values ( #id#, #firstName#, #lastName#, #emailAddress# ) </insert> Using StatementType for better control of IBatisAvailable as of Camel 1.6.1/2.0 from("direct:start") .to("ibatis:selectAccountById?statementType=QueryForObject") .to("mock:result"); In the code above we can invoke the iBatis statement selectAccountById and the IN body should contain the account id we want to retrieve, such as an Integer type. We can do the same for some of the other operations, such as QueryForList: from("direct:start") .to("ibatis:selectAllAccounts?statementType=QueryForList") .to("mock:result"); And the same for UPDATE, where we can send an Account object as IN body to iBatis: from("direct:start") .to("ibatis:updateAccount?statementType=Update") .to("mock:result"); Scheduled polling exampleSince this component does not support scheduled polling, you need to use another mechanism for triggering the scheduled polls, such as the Timer or Quartz components. In the sample below we poll the database, every 30 seconds using the Timer component and send the data to the JMS queue: from("timer://pollTheDatabase?delay=30000").to("ibatis:selectAllAccounts?statementType=QueryForList").to("activemq:queue:allAccounts");
And the iBatis SQL map file used: <!-- Select with no parameters using the result map for Account class. --> <select id="selectAllAccounts" resultMap="AccountResult"> select * from ACCOUNT </select> Using onConsumeThis component supports executing statements after data have been consumed and processed by Camel. This allows you to do post updates in the database. Notice all statements must be UPDATE statements. Camel supports executing multiple statements whose name should be separated by comma. The route below illustrates we execute the consumeAccount statement data is processed. This allows us to change the status of the row in the database to processed, so we avoid consuming it twice or more. from("ibatis:selectUnprocessedAccounts?consumer.onConsume=consumeAccount").to("mock:results"); And the statements in the sqlmap file: <select id="selectUnprocessedAccounts" resultMap="AccountResult"> select * from ACCOUNT where PROCESSED = false </select> <update id="consumeAccount" parameterClass="Account"> update ACCOUNT set PROCESSED = true where ACC_ID = #id# </update> See AlsoIRC ComponentThe irc component implements an IRC (Internet Relay Chat) transport. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-irc</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatirc:nick@host[:port]/#room[?options] In Camel 2.0, you can also use the following format: irc:nick@host[:port]?channels=#channel1,#channel2,#channel3[?options] You can append query options to the URI in the following format, ?option=value&option=value&... Options
SSL SupportUsing the JSSE Configuration UtilityAs of Camel 2.9, the IRC component supports SSL/TLS configuration through the Camel JSSE Configuration Utility. This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the IRC component. Programmatic configuration of the endpointKeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/truststore.jks"); ksp.setPassword("keystorePassword"); TrustManagersParameters tmp = new TrustManagersParameters(); tmp.setKeyStore(ksp); SSLContextParameters scp = new SSLContextParameters(); scp.setTrustManagers(tmp); Registry registry = ... registry.bind("sslContextParameters", scp); ... from(...) .to("ircs://camel-prd-user@server:6669/#camel-test?nickname=camel-prd&password=password&sslContextParameters=#sslContextParameters"); Spring DSL based configuration of endpoint...
<camel:sslContextParameters
id="sslContextParameters">
<camel:trustManagers>
<camel:keyStore
resource="/users/home/server/truststore.jks"
password="keystorePassword"/>
</camel:keyManagers>
</camel:sslContextParameters>...
...
<to uri="ircs://camel-prd-user@server:6669/#camel-test?nickname=camel-prd&password=password&sslContextParameters=#sslContextParameters"/>...
Using the legacy basic configuration optionsAs of Camel 2.0, you can also connect to an SSL enabled IRC server, as follows: ircs:host[:port]/#room?username=user&password=pass By default, the IRC transport uses SSLDefaultTrustManager. If you need to provide your own custom trust manager, use the trustManager parameter as follows: ircs:host[:port]/#room?username=user&password=pass&trustManager=#referenceToMyTrustManagerBean Using keysAvailable as of Camel 2.2 Some irc rooms requires you to provide a key to be able to join that channel. The key is just a secret word. For example we join 3 channels where as only channel 1 and 3 uses a key. irc:nick@irc.server.org?channels=#chan1,#chan2,#chan3&keys=chan1Key,,chan3key See AlsoJasypt componentAvailable as of Camel 2.5 Jasypt is a simplified encryption library which makes encryption and decryption easy. Camel integrates with Jasypt to allow sensitive information in Properties files to be encrypted. By dropping camel-jasypt on the classpath those encrypted values will automatic be decrypted on-the-fly by Camel. This ensures that human eyes can't easily spot sensitive information such as usernames and passwords. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jasypt</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> ToolingThe Jasypt component provides a little command line tooling to encrypt or decrypt values. The console output the syntax and which options it provides: Apache Camel Jasypt takes the following options -h or -help = Displays the help screen -c or -command <command> = Command either encrypt or decrypt -p or -password <password> = Password to use -i or -input <input> = Text to encrypt or decrypt -a or -algorithm <algorithm> = Optional algorithm to use For example to encrypt the value tiger you run with the following parameters. In the apache camel kit, you cd into the lib folder and run the following java cmd, where <CAMEL_HOME> is where you have downloaded and extract the Camel distribution. $ cd <CAMEL_HOME>/lib $ java -jar camel-jasypt-2.5.0.jar -c encrypt -p secret -i tiger Which outputs the following result Encrypted text: qaEEacuW7BUti8LcMgyjKw== This means the encrypted representation qaEEacuW7BUti8LcMgyjKw== can be decrypted back to tiger if you know the master password which was secret. So you can test it by running the tooling using the following parameters: $ cd <CAMEL_HOME>/lib $ java -jar camel-jasypt-2.5.0.jar -c decrypt -p secret -i qaEEacuW7BUti8LcMgyjKw== Which outputs the following result: Decrypted text: tiger The idea is then to use those encrypted values in your Properties files. Notice how the password value is encrypted and the value has the tokens surrounding ENC(value here) # refer to a mock endpoint name by that encrypted password
cool.result=mock:{{cool.password}}
# here is a password which is encrypted
cool.password=ENC(bsW9uV37gQ0QHFu7KO03Ww==)
Tooling dependencies for Camel 2.5 and 2.6The tooling requires the following JARs in the classpath, which has been enlisted in the MANIFEST.MF file of camel-jasypt with optional/ as prefix. Hence why the java cmd above can pickup the needed JARs from the Apache Distribution in the optional directory. jasypt-1.6.jar commons-lang-2.4.jar commons-codec-1.4.jar icu4j-4.0.1.jar
Tooling dependencies for Camel 2.7 or betterJasypt 1.7 onwards is now fully standalone so no additional JARs is needed. URI OptionsThe options below are exclusive for the Jasypt component.
Protecting the master passwordThe master password used by Jasypt must be provided, so its capable of decrypting the values. However having this master password out in the opening may not be an ideal solution. Therefore you could for example provided it as a JVM system property or as a OS environment setting. If you decide to do so then the password option supports prefixes which dictates this. sysenv: means to lookup the OS system environment with the given key. sys: means to lookup a JVM system property. For example you could provided the password before you start the application $ export CAMEL_ENCRYPTION_PASSWORD=secret Then start the application, such as running the start script. When the application is up and running you can unset the environment $ unset CAMEL_ENCRYPTION_PASSWORD The password option is then a matter of defining as follows: password=sysenv:CAMEL_ENCRYPTION_PASSWORD. Example with Java DSLIn Java DSL you need to configure Jasypt as a JasyptPropertiesParser instance and set it on the Properties component as show below: // create the jasypt properties parser JasyptPropertiesParser jasypt = new JasyptPropertiesParser(); // and set the master password jasypt.setPassword("secret"); // create the properties component PropertiesComponent pc = new PropertiesComponent(); pc.setLocation("classpath:org/apache/camel/component/jasypt/myproperties.properties"); // and use the jasypt properties parser so we can decrypt values pc.setPropertiesParser(jasypt); // add properties component to camel context context.addComponent("properties", pc); The properties file myproperties.properties then contain the encrypted value, such as shown below. Notice how the password value is encrypted and the value has the tokens surrounding ENC(value here) # refer to a mock endpoint name by that encrypted password
cool.result=mock:{{cool.password}}
# here is a password which is encrypted
cool.password=ENC(bsW9uV37gQ0QHFu7KO03Ww==)
Example with Spring XMLIn Spring XML you need to configure the JasyptPropertiesParser which is shown below. Then the Camel Properties component is told to use jasypt as the properties parser, which means Jasypt have its chance to decrypt values looked up in the properties. <!-- define the jasypt properties parser with the given password to be used --> <bean id="jasypt" class="org.apache.camel.component.jasypt.JasyptPropertiesParser"> <property name="password" value="secret"/> </bean> <!-- define the camel properties component --> <bean id="properties" class="org.apache.camel.component.properties.PropertiesComponent"> <!-- the properties file is in the classpath --> <property name="location" value="classpath:org/apache/camel/component/jasypt/myproperties.properties"/> <!-- and let it leverage the jasypt parser --> <property name="propertiesParser" ref="jasypt"/> </bean> The Properties component can also be inlined inside the <camelContext> tag which is shown below. Notice how we use the propertiesParserRef attribute to refer to Jasypt. <!-- define the jasypt properties parser with the given password to be used --> <bean id="jasypt" class="org.apache.camel.component.jasypt.JasyptPropertiesParser"> <!-- password is mandatory, you can prefix it with sysenv: or sys: to indicate it should use an OS environment or JVM system property value, so you dont have the master password defined here --> <property name="password" value="secret"/> </bean> <camelContext xmlns="http://camel.apache.org/schema/spring"> <!-- define the camel properties placeholder, and let it leverage jasypt --> <propertyPlaceholder id="properties" location="classpath:org/apache/camel/component/jasypt/myproperties.properties" propertiesParserRef="jasypt"/> <route> <from uri="direct:start"/> <to uri="{{cool.result}}"/> </route> </camelContext> See Also
JavaSpace ComponentAvailable as of Camel 2.1 The javaspace component is a transport for working with any JavaSpace compliant implementation and this component has been tested with both the Blitz implementation and the GigaSpace implementation . Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-javaspace</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
javaspace:jini://host[?options]
You can append query options to the URI in the following format, ?option=value&option=value&... Options
ExamplesSending and Receiving Entries// sending route from("direct:input") .to("javaspace:jini://localhost?spaceName=mySpace"); // receiving Route from("javaspace:jini://localhost?spaceName=mySpace&templateId=template&verb=take&concurrentConsumers=1") .to("mock:foo"); In this case the payload can be any object that inherits from the Jini Entry type. Sending and receiving serializable objectsUsing the preceding routes, it is also possible to send and receive any serializable object. The JavaSpace component detects that the payload is not a Jini Entry and then it automatically wraps the payload with a Camel Jini Entry. In this way, a JavaSpace can be used as a generic transport mechanism. Using JavaSpace as a remote invocation transportThe JavaSpace component has been tailored to work in combination with the Camel bean component. It is therefore possible to call a remote POJO using JavaSpace as the transport: // client side from("direct:input") .to("javaspace:jini://localhost?spaceName=mySpace"); // server side from("javaspace:jini://localhost?concurrentConsumers=10&spaceName=mySpace") .to("mock:foo"); In the code there are two test cases showing how to use a POJO to realize the master/worker pattern. The idea is to use the POJO to provide the business logic and rely on Camel for sending/receiving requests/replies with the proper correlation. See AlsoJBI ComponentThe jbi component is implemented by the ServiceMix Camel module and provides integration with a JBI Normalized Message Router, such as the one provided by Apache ServiceMix.
The following code:
from("jbi:endpoint:http://foo.bar.org/MyService/MyEndpoint")
Automatically exposes a new endpoint to the bus, where the service QName is {http://foo.bar.org}MyService and the endpoint name is MyEndpoint (see URI-format). When a JBI endpoint appears at the end of a route, for example:
to("jbi:endpoint:http://foo.bar.org/MyService/MyEndpoint")
The messages sent by this producer endpoint are sent to the already deployed JBI endpoint. URI formatjbi:service:serviceNamespace[sep]serviceName[?options] jbi:endpoint:serviceNamespace[sep]serviceName[sep]endpointName[?options] jbi:name:endpointName[?options] The separator that should be used in the endpoint URL is:
For more details of valid JBI URIs see the ServiceMix URI Guide. Using the jbi:service: or jbi:endpoint: URI formats sets the service QName on the JBI endpoint to the one specified. Otherwise, the default Camel JBI Service QName is used, which is:
{http://activemq.apache.org/camel/schema/jbi}endpoint
You can append query options to the URI in the following format, ?option=value&option=value&... Examplesjbi:service:http://foo.bar.org/MyService jbi:endpoint:urn:foo:bar:MyService:MyEndpoint jbi:endpoint:http://foo.bar.org/MyService/MyEndpoint jbi:name:cheese URI options
Examplesjbi:service:http://foo.bar.org/MyService?mep=in-out (override the MEP, use InOut JBI MessageExchanges) jbi:endpoint:urn:foo:bar:MyService:MyEndpoint?mep=in (override the MEP, use InOnly JBI MessageExchanges) jbi:endpoint:urn:foo:bar:MyService:MyEndpoint?operation={http://www.mycompany.org}AddNumbers (overide the operation for the JBI Exchange to {http://www.mycompany.org}AddNumbers) Using Stream bodiesIf you are using a stream type as the message body, you should be aware that a stream is only capable of being read once. So if you enable DEBUG logging, the body is usually logged and thus read. To deal with this, Camel has a streamCaching option that can cache the stream, enabling you to read it multiple times.
from("jbi:endpoint:http://foo.bar.org/MyService/MyEndpoint").streamCaching().to("xslt:transform.xsl", "bean:doSomething");
From Camel 1.5 onwards, the stream caching is default enabled, so it is not necessary to set the streamCaching() option. Creating a JBI Service UnitIf you have some Camel routes that you want to deploy inside JBI as a Service Unit, you can use the JBI Service Unit Archetype to create a new Maven project for the Service Unit. If you have an existing Maven project that you need to convert into a JBI Service Unit, you may want to consult ServiceMix Maven JBI Plugins for further help. The key steps are as follows:
Your pom.xml should look something like this to enable the jbi-service-unit packaging: <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>myGroupId</groupId> <artifactId>myArtifactId</artifactId> <packaging>jbi-service-unit</packaging> <version>1.0-SNAPSHOT</version> <name>A Camel based JBI Service Unit</name> <url>http://www.myorganization.org</url> <properties> <camel-version>1.0.0</camel-version> <servicemix-version>3.3</servicemix-version> </properties> <dependencies> <dependency> <groupId>org.apache.servicemix</groupId> <artifactId>servicemix-camel</artifactId> <version>${servicemix-version}</version> </dependency> <dependency> <groupId>org.apache.servicemix</groupId> <artifactId>servicemix-core</artifactId> <version>${servicemix-version}</version> <scope>provided</scope> </dependency> </dependencies> <build> <defaultGoal>install</defaultGoal> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.5</source> <target>1.5</target> </configuration> </plugin> <!-- creates the JBI deployment unit --> <plugin> <groupId>org.apache.servicemix.tooling</groupId> <artifactId>jbi-maven-plugin</artifactId> <version>${servicemix-version}</version> <extensions>true</extensions> </plugin> </plugins> </build> </project> See AlsoJCR ComponentThe jcr component allows you to add nodes to a JCR compliant content repository (for example, Apache Jackrabbit). Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jcr</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
URI format
jcr://user:password@repository/path/to/node
UsageThe repository element of the URI is used to look up the JCR Repository object in the Camel context registry. If a message is sent to a JCR producer endpoint:
Message propertiesAll message properties are converted to node properties, except for the CamelJcrNodeName property (you can refer to JcrConstants.NODE_NAME in your code), which is used to determine the node name. ExampleThe snippet below creates a node named node under the /home/test node in the content repository. One additional attribute is added to the node as well: my.contents.property which will contain the body of the message being sent. from("direct:a").setProperty(JcrConstants.JCR_NODE_NAME, constant("node")) .setProperty("my.contents.property", body()).to("jcr://user:pass@repository/home/test"); See AlsoJDBC ComponentThe jdbc component enables you to access databases through JDBC, where SQL queries and operations are sent in the message body. This component uses the standard JDBC API, unlike the SQL Component component, which uses spring-jdbc. Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jdbc</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
URI formatjdbc:dataSourceName[?options] This component only supports producer endpoints. You can append query options to the URI in the following format, ?option=value&option=value&... Options
ResultThe result is returned in the OUT body as an ArrayList<HashMap<String, Object>>. The List object contains the list of rows and the Map objects contain each row with the String key as the column name. Note: This component fetches ResultSetMetaData to be able to return the column name as the key in the Map. Message Headers
SamplesIn the following example, we fetch the rows from the customer table. First we register our datasource in the Camel registry as testdb: JndiRegistry reg = super.createRegistry(); reg.bind("testdb", db); return reg; Then we configure a route that routes to the JDBC component, so the SQL will be executed. Note how we refer to the testdb datasource that was bound in the previous step: // lets add simple route public void configure() throws Exception { from("direct:hello").to("jdbc:testdb?readSize=100"); } Or you can create a DataSource in Spring like this: <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="timer://kickoff?period=10000"/> <setBody> <constant>select * from customer</constant> </setBody> <to uri="jdbc:testdb"/> <to uri="mock:result"/> </route> </camelContext> <!-- Just add a demo to show how to bind a date source for camel in Spring--> <jdbc:embedded-database id="testdb" type="DERBY"> <jdbc:script location="classpath:sql/init.sql"/> </jdbc:embedded-database> We create an endpoint, add the SQL query to the body of the IN message, and then send the exchange. The result of the query is returned in the OUT body: // first we create our exchange using the endpoint Endpoint endpoint = context.getEndpoint("direct:hello"); Exchange exchange = endpoint.createExchange(); // then we set the SQL on the in body exchange.getIn().setBody("select * from customer order by ID"); // now we send the exchange to the endpoint, and receives the response from Camel Exchange out = template.send(endpoint, exchange); // assertions of the response assertNotNull(out); assertNotNull(out.getOut()); ArrayList<HashMap<String, Object>> data = out.getOut().getBody(ArrayList.class); assertNotNull(data); assertEquals(3, data.size()); HashMap<String, Object> row = data.get(0); assertEquals("cust1", row.get("ID")); assertEquals("jstrachan", row.get("NAME")); row = data.get(1); assertEquals("cust2", row.get("ID")); assertEquals("nsandhu", row.get("NAME")); If you want to work on the rows one by one instead of the entire ResultSet at once you need to use the Splitter EIP such as: from("direct:hello") // here we split the data from the testdb into new messages one by one // so the mock endpoint will receive a message per row in the table .to("jdbc:testdb").split(body()).to("mock:result"); Sample - Polling the database every minuteIf we want to poll a database using the JDBC component, we need to combine it with a polling scheduler such as the Timer or Quartz etc. In the following example, we retrieve data from the database every 60 seconds:
from("timer://foo?period=60000").setBody(constant("select * from customer")).to("jdbc:testdb").to("activemq:queue:customers");
See AlsoJetty ComponentThe jetty component provides HTTP-based endpoints for consuming HTTP requests. That is, the Jetty component behaves as a simple Web server.
URI format
jetty:http://hostname[:port][/resourceUri][?options]
You can append query options to the URI in the following format, ?option=value&option=value&... Options
Message HeadersCamel uses the same message headers as the HTTP component. Camel also populates all request.parameter and request.headers. For example, given a client request with the URL, http://myserver/myserver?orderid=123, the exchange will contain a header named orderid with the value 123. Starting with Camel 2.2.0, you can get the request.parameter from the message header not only from Get Method, but also other HTTP method. UsageThe Jetty component only supports consumer endpoints. Therefore a Jetty endpoint URI should be used only as the input for a Camel route (in a from() DSL call). To issue HTTP requests against other HTTP endpoints, use the HTTP Component Component OptionsThe JettyHttpComponent provides the following options:
SampleIn this sample we define a route that exposes a HTTP service at http://localhost:8080/myapp/myservice: from("jetty:http://localhost:{{port}}/myapp/myservice").process(new MyBookService());
Our business logic is implemented in the MyBookService class, which accesses the HTTP request contents and then returns a response. public class MyBookService implements Processor { public void process(Exchange exchange) throws Exception { // just get the body as a string String body = exchange.getIn().getBody(String.class); // we have access to the HttpServletRequest here and we can grab it if we need it HttpServletRequest req = exchange.getIn().getBody(HttpServletRequest.class); assertNotNull(req); // for unit testing assertEquals("bookid=123", body); // send a html response exchange.getOut().setBody("<html><body>Book 123 is Camel in Action</body></html>"); } } The following sample shows a content-based route that routes all requests containing the URI parameter, one, to the endpoint, mock:one, and all others to mock:other. from("jetty:" + serverUri) .choice() .when().simple("${header.one}").to("mock:one") .otherwise() .to("mock:other"); So if a client sends the HTTP request, http://serverUri?one=hello, the Jetty component will copy the HTTP request parameter, one to the exchange's in.header. We can then use the simple language to route exchanges that contain this header to a specific endpoint and all others to another. If we used a language more powerful than Simple-- Session SupportThe session support option, sessionSupport, can be used to enable a HttpSession object and access the session object while processing the exchange. For example, the following route enables sessions: <route> <from uri="jetty:http://0.0.0.0/myapp/myservice/?sessionSupport=true"/> <processRef ref="myCode"/> <route> The myCode Processor can be instantiated by a Spring bean element:
<bean id="myCode"class="com.mycompany.MyCodeProcessor"/>
Where the processor implementation can access the HttpSession as follows: public void process(Exchange exchange) throws Exception { HttpSession session = exchange.getIn(HttpMessage.class).getRequest().getSession(); ... } SSL Support (HTTPS)Using the JSSE Configuration UtilityAs of Camel 2.8, the Jetty component supports SSL/TLS configuration through the Camel JSSE Configuration Utility. This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the Jetty component. Programmatic configuration of the componentKeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); JettyComponent jettyComponent = getContext().getComponent("jetty", JettyComponent.class); jettyComponent.setSslContextParameters(scp); Spring DSL based configuration of endpoint
...
<camel:sslContextParameters
id="sslContextParameters">
<camel:keyManagers
keyPassword="keyPassword">
<camel:keyStore
resource="/users/home/server/keystore.jks"
password="keystorePassword"/>
</camel:keyManagers>
</camel:sslContextParameters>...
...
<to uri="jetty:https://127.0.0.1/mail/?sslContextParametersRef=sslContextParameters"/>
...
Configuring Jetty DirectlyJetty provides SSL support out of the box. To enable Jetty to run in SSL mode, simply format the URI with the https:// prefix---for example:
<from uri="jetty:https://0.0.0.0/myapp/myservice/"/>
Jetty also needs to know where to load your keystore from and what passwords to use in order to load the correct SSL certificate. Set the following JVM System Properties: until Camel 2.2
from Camel 2.3 onwards
For details of how to configure SSL on a Jetty endpoint, read the following documentation at the Jetty Site: http://docs.codehaus.org/display/JETTY/How+to+configure+SSL Some SSL properties aren't exposed directly by Camel, however Camel does expose the underlying SslSocketConnector, which will allow you to set properties like needClientAuth for mutual authentication requiring a client certificate or wantClientAuth for mutual authentication where a client doesn't need a certificate but can have one. There's a slight difference between the various Camel versions: Up to Camel 2.2 <bean id="jetty" class="org.apache.camel.component.jetty.JettyHttpComponent"> <property name="sslSocketConnectors"> <map> <entry key="8043"> <bean class="org.mortbay.jetty.security.SslSocketConnector"> <property name="password"value="..."/> <property name="keyPassword"value="..."/> <property name="keystore"value="..."/> <property name="needClientAuth"value="..."/> <property name="truststore"value="..."/> </bean> </entry> </map> </property> </bean> Camel 2.3, 2.4 <bean id="jetty" class="org.apache.camel.component.jetty.JettyHttpComponent"> <property name="sslSocketConnectors"> <map> <entry key="8043"> <bean class="org.eclipse.jetty.server.ssl.SslSocketConnector"> <property name="password"value="..."/> <property name="keyPassword"value="..."/> <property name="keystore"value="..."/> <property name="needClientAuth"value="..."/> <property name="truststore"value="..."/> </bean> </entry> </map> </property> </bean> *From Camel 2.5 we switch to use SslSelectChannelConnector * <bean id="jetty" class="org.apache.camel.component.jetty.JettyHttpComponent"> <property name="sslSocketConnectors"> <map> <entry key="8043"> <bean class="org.eclipse.jetty.server.ssl.SslSelectChannelConnector"> <property name="password"value="..."/> <property name="keyPassword"value="..."/> <property name="keystore"value="..."/> <property name="needClientAuth"value="..."/> <property name="truststore"value="..."/> </bean> </entry> </map> </property> </bean> The value you use as keys in the above map is the port you configure Jetty to listen on. Configuring general SSL propertiesAvailable as of Camel 2.5 Instead of a per port number specific SSL socket connector (as shown above) you can now configure general properties which applies for all SSL socket connectors (which is not explicit configured as above with the port number as entry). <bean id="jetty" class="org.apache.camel.component.jetty.JettyHttpComponent"> <property name="sslSocketConnectorProperties"> <properties> <property name="password"value="..."/> <property name="keyPassword"value="..."/> <property name="keystore"value="..."/> <property name="needClientAuth"value="..."/> <property name="truststore"value="..."/> </properties> </property> </bean> How to obtain reference to the X509CertificateJetty stores a reference to the certificate in the HttpServletRequest which you can access from code as follows:
HttpServletRequest req = exchange.getIn().getBody(HttpServletRequest.class);
X509Certificate cert = (X509Certificate) req.getAttribute("javax.servlet.request.X509Certificate")
Configuring general HTTP propertiesAvailable as of Camel 2.5 Instead of a per port number specific HTTP socket connector (as shown above) you can now configure general properties which applies for all HTTP socket connectors (which is not explicit configured as above with the port number as entry). <bean id="jetty" class="org.apache.camel.component.jetty.JettyHttpComponent"> <property name="socketConnectorProperties"> <properties> <property name="acceptors" value="4"/> <property name="maxIdleTime" value="300000"/> </properties> </property> </bean> Default behavior for returning HTTP status codesThe default behavior of HTTP status codes is defined by the org.apache.camel.component.http.DefaultHttpBinding class, which handles how a response is written and also sets the HTTP status code. If the exchange was processed successfully, the 200 HTTP status code is returned. Customizing HttpBindingBy default, Camel uses the org.apache.camel.component.http.DefaultHttpBinding to handle how a response is written. If you like, you can customize this behavior either by implementing your own HttpBinding class or by extending DefaultHttpBinding and overriding the appropriate methods. The following example shows how to customize the DefaultHttpBinding in order to change how exceptions are returned: public class MyJettyHttpBinding extends DefaultJettyHttpBinding { @Override protected void populateResponse(Exchange exchange, JettyContentExchange httpExchange, Message in, HeaderFilterStrategy strategy, int responseCode) throws IOException { Message answer = exchange.getOut(); answer.setHeaders(in.getHeaders()); answer.setHeader(Exchange.HTTP_RESPONSE_CODE, responseCode); answer.setBody("Not exactly the message the server returned."); } } We can then create an instance of our binding and register it in the Spring registry as follows:
<bean id="mybinding"class="com.mycompany.MyHttpBinding"/>
And then we can reference this binding when we define the route: <route><from uri="jetty:http://0.0.0.0:8080/myapp/myservice?httpBindingRef=mybinding"/><to uri="bean:doSomething"/></route> Jetty handlers and security configurationYou can configure a list of Jetty handlers on the endpoint, which can be useful for enabling advanced Jetty security features. These handlers are configured in Spring XML as follows: <-- Jetty Security handling --> <bean id="userRealm" class="org.mortbay.jetty.plus.jaas.JAASUserRealm"> <property name="name" value="tracker-users"/> <property name="loginModuleName" value="ldaploginmodule"/> </bean> <bean id="constraint" class="org.mortbay.jetty.security.Constraint"> <property name="name" value="BASIC"/> <property name="roles" value="tracker-users"/> <property name="authenticate" value="true"/> </bean> <bean id="constraintMapping" class="org.mortbay.jetty.security.ConstraintMapping"> <property name="constraint" ref="constraint"/> <property name="pathSpec" value="/*"/> </bean> <bean id="securityHandler" class="org.mortbay.jetty.security.SecurityHandler"> <property name="userRealm" ref="userRealm"/> <property name="constraintMappings" ref="constraintMapping"/> </bean> And from Camel 2.3 onwards you can configure a list of Jetty handlers as follows: <-- Jetty Security handling --> <bean id="constraint" class="org.eclipse.jetty.http.security.Constraint"> <property name="name" value="BASIC"/> <property name="roles" value="tracker-users"/> <property name="authenticate" value="true"/> </bean> <bean id="constraintMapping" class="org.eclipse.jetty.security.ConstraintMapping"> <property name="constraint" ref="constraint"/> <property name="pathSpec" value="/*"/> </bean> <bean id="securityHandler" class="org.eclipse.jetty.security.ConstraintSecurityHandler"> <property name="authenticator"> <bean class="org.eclipse.jetty.security.authentication.BasicAuthenticator"/> </property> <property name="constraintMappings"> <list> <ref bean="constraintMapping"/> </list> </property> </bean> You can then define the endpoint as:
from("jetty:http://0.0.0.0:9080/myservice?handlers=securityHandler")
If you need more handlers, set the handlers option equal to a comma-separated list of bean IDs. How to return a custom HTTP 500 reply messageYou may want to return a custom reply message when something goes wrong, instead of the default reply message Camel Jetty replies with. from("jetty://http://localhost:{{port}}/myserver") // use onException to catch all exceptions and return a custom reply message .onException(Exception.class) .handled(true) // create a custom failure response .transform(constant("Dude something went wrong")) // we must remember to set error code 500 as handled(true) // otherwise would let Camel thing its a OK response (200) .setHeader(Exchange.HTTP_RESPONSE_CODE, constant(500)) .end() // now just force an exception immediately .throwException(new IllegalArgumentException("I cannot do this")); Multi-part Form supportFrom Camel 2.3.0, camel-jetty support to multipart form post out of box. The submitted form-data are mapped into the message header. Camel-jetty creates an attachment for each uploaded file. The file name is mapped to the name of the attachment. The content type is set as the content type of the attachment file name. You can find the example here. Note: getName() functions as shown below in versions 2.5 and higher. In earlier versions you receive the temporary file name for the attachment instead // Set the jetty temp directory which store the file for multi part form // camel-jetty will clean up the file after it handled the request. // The option works rightly from Camel 2.4.0 getContext().getProperties().put("CamelJettyTempDir", "target"); from("jetty://http://localhost:{{port}}/test").process(new Processor() { public void process(Exchange exchange) throws Exception { Message in = exchange.getIn(); assertEquals("Get a wrong attachement size", 1, in.getAttachments().size()); // The file name is attachment id DataHandler data = in.getAttachment("NOTICE.txt"); assertNotNull("Should get the DataHandle NOTICE.txt", data); // This assert is wrong, but the correct content-type (application/octet-stream) // will not be returned until Jetty makes it available - currently the content-type // returned is just the default for FileDataHandler (for the implentation being used) //assertEquals("Get a wrong content type", "text/plain", data.getContentType()); assertEquals("Got the wrong name", "NOTICE.txt", data.getName()); assertTrue("We should get the data from the DataHandle", data.getDataSource() .getInputStream().available() > 0); // The other form date can be get from the message header exchange.getOut().setBody(in.getHeader("comment")); } }); Jetty JMX supportFrom Camel 2.3.0, camel-jetty supports the enabling of Jetty's JMX capabilities at the component and endpoint level with the endpoint configuration taking priority. Note that JMX must be enabled within the Camel context in order to enable JMX support in this component as the component provides Jetty with a reference to the MBeanServer registered with the Camel context. Because the camel-jetty component caches and reuses Jetty resources for a given protocol/host/port pairing, this configuration option will only be evaluated during the creation of the first endpoint to use a protocol/host/port pairing. For example, given two routes created from the following XML fragments, JMX support would remain enabled for all endpoints listening on "https://0.0.0.0".
<from uri="jetty:https://0.0.0.0/myapp/myservice1/?enableJmx=true"/>
<from uri="jetty:https://0.0.0.0/myapp/myservice2/?enableJmx=false"/>
The camel-jetty component also provides for direct configuration of the Jetty MBeanContainer. Jetty creates MBean names dynamically. If you are running another instance of Jetty outside of the Camel context and sharing the same MBeanServer between the instances, you can provide both instances with a reference to the same MBeanContainer in order to avoid name collisions when registering Jetty MBeans. See AlsoJing ComponentThe Jing component uses the Jing Library to perform XML validation of the message body using either Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-jing</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
Note that the MSV component can also support RelaxNG XML syntax. URI formatrng:someLocalOrRemoteResource rnc:someLocalOrRemoteResource Where rng means use the RelaxNG XML Syntax whereas rnc means use RelaxNG Compact Syntax. The following examples show possible URI values
You can append query options to the URI in the following format, ?option=value&option=value&... Options
ExampleThe following example shows how to configure a route from the endpoint direct:start which then goes to one of two endpoints, either mock:valid or mock:invalid based on whether or not the XML matches the given RelaxNG Compact Syntax schema (which is supplied on the classpath). <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <doTry> <to uri="rnc:org/apache/camel/component/validator/jing/schema.rnc"/> <to uri="mock:valid"/> <doCatch> <exception>org.apache.camel.ValidationException</exception> <to uri="mock:invalid"/> </doCatch> <doFinally> <to uri="mock:finally"/> </doFinally> </doTry> </route> </camelContext> See AlsoJMS Component
The JMS component allows messages to be sent to (or consumed from) a JMS Queue or Topic. The implementation of the JMS Component uses Spring's JMS support for declarative transactions, using Spring's JmsTemplate for sending and a MessageListenerContainer for consuming. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jms</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatjms:[queue:|topic:]destinationName[?options] Where destinationName is a JMS queue or topic name. By default, the destinationName is interpreted as a queue name. For example, to connect to the queue, FOO.BAR use: jms:FOO.BAR You can include the optional queue: prefix, if you prefer: jms:queue:FOO.BAR To connect to a topic, you must include the topic: prefix. For example, to jms:topic:Stocks.Prices You append query options to the URI using the following format, ?option=value&option=value&... NotesUsing ActiveMQThe JMS component reuses Spring 2's JmsTemplate for sending messages. This is not ideal for use in a non-J2EE container and typically requires some caching in the JMS provider to avoid poor performance. If you intend to use Apache ActiveMQ as your Message Broker - which is a good choice as ActiveMQ rocks
Transactions and Cache Levels
If you are not using XA, then you should consider caching as it speeds up performance, such as setting cacheLevelName=CACHE_CONSUMER. Through Camel 2.7.x, the default setting for cacheLevelName is CACHE_CONSUMER. You will need to explicitly set cacheLevelName=CACHE_NONE.
So you can say the default setting is conservative. Consider using cacheLevelName=CACHE_CONSUMER if you are using non-XA transactions. Durable SubscriptionsIf you wish to use durable topic subscriptions, you need to specify both clientId and durableSubscriptionName. The value of the clientId must be unique and can only be used by a single JMS connection instance in your entire network. You may prefer to use Virtual Topics instead to avoid this limitation. More background on durable messaging here. Message Header MappingWhen using message headers, the JMS specification states that header names must be valid Java identifiers. So, by default, Camel ignores any headers that do not match this rule. So try to name your headers as if they are valid Java identifiers. One benefit of doing this is that you can then use your headers inside a JMS Selector (whose SQL92 syntax mandates Java identifier syntax for headers). A simple strategy for mapping header names is used by default. The strategy is to replace any dots and hyphens in the header name as shown below and to reverse the replacement when the header name is restored from a JMS message sent over the wire. What does this mean? No more losing method names to invoke on a bean component, no more losing the filename header for the File Component, and so on. The current header name strategy for accepting header names in Camel is as follows:
OptionsYou can configure many different properties on the JMS endpoint which map to properties on the JMSConfiguration POJO.
The options are divided into two tables, the first one with the most common options used. The latter contains the rest. Most commonly used options
All the other options
Message Mapping between JMS and CamelCamel automatically maps messages between javax.jms.Message and org.apache.camel.Message. When sending a JMS message, Camel converts the message body to the following JMS message types:
When receiving a JMS message, Camel converts the JMS message to the following body type:
Disabling auto-mapping of JMS messagesYou can use the mapJmsMessage option to disable the auto-mapping above. If disabled, Camel will not try to map the received JMS message, but instead uses it directly as the payload. This allows you to avoid the overhead of mapping and let Camel just pass through the JMS message. For instance, it even allows you to route javax.jms.ObjectMessage JMS messages with classes you do not have on the classpath. Using a custom MessageConverterYou can use the messageConverter option to do the mapping yourself in a Spring org.springframework.jms.support.converter.MessageConverter class. For example, in the route below we use a custom message converter when sending a message to the JMS order queue:
from("file://inbox/order").to("jms:queue:order?messageConverter=#myMessageConverter");
You can also use a custom message converter when consuming from a JMS destination. Controlling the mapping strategy selectedYou can use the jmsMessageType option on the endpoint URL to force a specific message type for all messages.
from("file://inbox/order").to("jms:queue:order?jmsMessageType=Text");
You can also specify the message type to use for each messabe by setting the header with the key CamelJmsMessageType. For example:
from("file://inbox/order").setHeader("CamelJmsMessageType", JmsMessageType.Text).to("jms:queue:order");
The possible values are defined in the enum class, org.apache.camel.jms.JmsMessageType. Message format when sendingThe exchange that is sent over the JMS wire must conform to the JMS Message spec. For the exchange.in.header the following rules apply for the header keys:
For the exchange.in.header, the following rules apply for the header values:
Camel will log with category org.apache.camel.component.jms.JmsBinding at DEBUG level if it drops a given header value. For example:
2008-07-09 06:43:04,046 [main ] DEBUG JmsBinding
- Ignoring non primitive header: order of class: org.apache.camel.component.jms.issues.DummyOrder with value: DummyOrder{orderId=333, itemId=4444, quantity=2}
Message format when receivingCamel adds the following properties to the Exchange when it receives a message:
Camel adds the following JMS properties to the In message headers when it receives a JMS message:
As all the above information is standard JMS you can check the JMS documentation for further details. About using Camel to send and receive messages and JMSReplyToThe JMS component is complex and you have to pay close attention to how it works in some cases. So this is a short summary of some of the areas/pitfalls to look for. When Camel sends a message using its JMSProducer, it checks the following conditions:
All this can be a tad complex to understand and configure to support your use case. JmsProducerThe JmsProducer behaves as follows, depending on configuration:
JmsConsumerThe JmsConsumer behaves as follows, depending on configuration:
So pay attention to the message exchange pattern set on your exchanges. If you send a message to a JMS destination in the middle of your route you can specify the exchange pattern to use, see more at Request Reply. from("activemq:queue:in") .to("bean:validateOrder") .to(ExchangePattern.InOnly, "activemq:topic:order") .to("bean:handleOrder"); Reuse endpoint and send to different destinations computed at runtimeIf you need to send messages to a lot of different JMS destinations, it makes sense to reuse a JMS endpoint and specify the real destination in a message header. This allows Camel to reuse the same endpoint, but send to different destinations. This greatly reduces the number of endpoints created and economizes on memory and thread resources. You can specify the destination in the following headers:
For example, the following route shows how you can compute a destination at run time and use it to override the destination appearing in the JMS URL: from("file://inbox") .to("bean:computeDestination") .to("activemq:queue:dummy"); The queue name, dummy, is just a placeholder. It must be provided as part of the JMS endpoint URL, but it will be ignored in this example. In the computeDestination bean, specify the real destination by setting the CamelJmsDestinationName header as follows: public void setJmsHeader(Exchange exchange) { String id = .... exchange.getIn().setHeader("CamelJmsDestinationName", "order:" + id"); } Then Camel will read this header and use it as the destination instead of the one configured on the endpoint. So, in this example Camel sends the message to activemq:queue:order:2, assuming the id value was 2. If both the CamelJmsDestination and the CamelJmsDestinationName headers are set, CamelJmsDestination takes priority. Configuring different JMS providersYou can configure your JMS provider in Spring XML as follows: <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <jmxAgent id="agent" disabled="true"/> </camelContext> <bean id="activemq" class="org.apache.activemq.camel.component.ActiveMQComponent"> <property name="connectionFactory"> <bean class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="vm://localhost?broker.persistent=false&broker.useJmx=false"/> </bean> </property> </bean> Basically, you can configure as many JMS component instances as you wish and give them a unique name using the id attribute. The preceding example configures an activemq component. You could do the same to configure MQSeries, TibCo, BEA, Sonic and so on. Once you have a named JMS component, you can then refer to endpoints within that component using URIs. For example for the component name, activemq, you can then refer to destinations using the URI format, activemq:[queue:|topic:]destinationName. You can use the same approach for all other JMS providers. This works by the SpringCamelContext lazily fetching components from the spring context for the scheme name you use for Endpoint URIs and having the Component resolve the endpoint URIs. Using JNDI to find the ConnectionFactoryIf you are using a J2EE container, you might need to look up JNDI to find the JMS ConnectionFactory rather than use the usual <bean> mechanism in Spring. You can do this using Spring's factory bean or the new Spring XML namespace. For example: <bean id="weblogic" class="org.apache.camel.component.jms.JmsComponent"> <property name="connectionFactory" ref="myConnectionFactory"/> </bean> <jee:jndi-lookup id="myConnectionFactory" jndi-name="jms/connectionFactory"/> See The jee schema in the Spring reference documentation for more details about JNDI lookup. Concurrent ConsumingA common requirement with JMS is to consume messages concurrently in multiple threads in order to make an application more responsive. You can set the concurrentConsumers option to specify the number of threads servicing the JMS endpoint, as follows:
from("jms:SomeQueue?concurrentConsumers=20").
bean(MyClass.class);
You can configure this option in one of the following ways:
Request-reply over JMSCamel supports Request Reply over JMS. In essence the MEP of the Exchange should be InOut when you send a message to a JMS queue. Camel will automatic setup a consumer which listen on the reply queue, so you should not do anything.
from(xxx)
.inOut().to("activemq:queue:foo")
.threads(5)
.to(yyy)
.to(zzz);
In this route we instruct Camel to route replies asynchronously using a thread pool with 5 threads. Request-reply over JMS and using a shared fixed reply queueIf you use a fixed reply queue when doing Request Reply over JMS as shown in the example below, then pay attention.
from(xxx)
.inOut().to("activemq:queue:foo?replyTo=bar")
.to(yyy)
In this example the fixed reply queue named "bar" is used. By default Camel assumes the queue is shared when using fixed reply queues, and therefore it uses a JMSSelector to only pickup the expected reply messages (eg based on the JMSCorrelationID). See next section for exclusive fixed reply queues. That means its not as fast as temporary queues. You can speedup how often Camel will pull for reply messages using the receiveTimeout option. By default its 1000 millis. So to make it faster you can set it to 250 millis to pull 4 times per second as shown:
from(xxx)
.inOut().to("activemq:queue:foo?replyTo=bar&receiveTimeout=250")
.to(yyy)
Notice this will cause the Camel to send pull requests to the message broker more frequent, and thus require more network traffic. Request-reply over JMS and using an exclusive fixed reply queueAvailable as of Camel 2.9 In the previous example, Camel would anticipate the fixed reply queue named "bar" was shared, and thus it uses a JMSSelector to only consume reply messages which it expects. However there is a drawback doing this as JMS selectos is slower. Also the consumer on the reply queue is slower to update with new JMS selector ids. In fact it only updates when the receiveTimeout option times out, which by default is 1 second. So in theory the reply messages could take up till about 1 sec to be detected. On the other hand if the fixed reply queue is exclusive to the Camel reply consumer, then we can avoid using the JMS selectors, and thus be more performant. In fact as fast as using temporary queues. So in Camel 2.9 onwards we introduced the ReplyToType option which you can configure to Exclusive
from(xxx)
.inOut().to("activemq:queue:foo?replyTo=bar?replyToType=Exclusive")
.to(yyy)
Mind that the queue must be exclusive to each and every endpoint. So if you have two routes, then they each need an unique reply queue as shown in the next example: from(xxx) .inOut().to("activemq:queue:foo?replyTo=bar?replyToType=Exclusive") .to(yyy) from(aaa) .inOut().to("activemq:queue:order?replyTo=order.reply?replyToType=Exclusive") .to(bbb) The same applies if you run in a clustered environment. Then each node in the cluster must use an unique reply queue name. As otherwise each node in the cluster may pickup messages which was intended as a reply on another node. For clustered environments its recommended to use shared reply queues instead. Synchronizing clocks between senders and receiversWhen doing messaging between systems, its desirable that the systems have synchronized clocks. For example when sending a JMS message, then you can set a time to live value on the message. Then the receiver can inspect this value, and determine if the message is already expired, and thus drop the message instead of consume and process it. However this requires that both sender and receiver have synchronized clocks. If you are using ActiveMQ then you can use the timestamp plugin to synchronize clocks. About time to liveRead first above about synchronized clocks. When you do request/reply (InOut) over JMS with Camel then Camel uses a timeout on the sender side, which is default 20 seconds from the requestTimeout option. You can control this by setting a higher/lower value. However the time to live value is still set on the JMS message being send. So that requires the clocks to be synchronized between the systems. If they are not, then you may want to disable the time to live value being set. This is now possible using the disableTimeToLive option from Camel 2.8 onwards. So if you set this option to disableTimeToLive=true, then Camel does not set any time to live value when sending JMS messages. But the request timeout is still active. So for example if you do request/reply over JMS and have disabled time to live, then Camel will still use a timeout by 20 seconds (the requestTimeout option). That option can of course also be configured. So the two options requestTimeout and disableTimeToLive gives you fine grained control when doing request/reply. When you do fire and forget (InOut) over JMS with Camel then Camel by default does not set any time to live value on the message. You can configure a value by using the timeToLive option. For example to indicate a 5 sec., you set timeToLive=5000. The option disableTimeToLive can be used to force disabling the time to live, also for InOnly messaging. The requestTimeout option is not being used for InOnly messaging. Enabling Transacted ConsumptionA common requirement is to consume from a queue in a transaction and then process the message using the Camel route. To do this, just ensure that you set the following properties on the component/endpoint:
See the Transactional Client EIP pattern for further details.
Using JMSReplyTo for late repliesWhen using Camel as a JMS listener, it sets an Exchange property with the value of the ReplyTo javax.jms.Destination object, having the key ReplyTo. You can obtain this Destination as follows: Destination replyDestination = exchange.getIn().getHeader(JmsConstants.JMS_REPLY_DESTINATION, Destination.class); And then later use it to send a reply using regular JMS or Camel.
// we need to pass in the JMS component, and in this sample we use ActiveMQ
JmsEndpoint endpoint = JmsEndpoint.newInstance(replyDestination, activeMQComponent);
// now we have the endpoint we can use regular Camel API to send a message to it
template.sendBody(endpoint, "Here is the late reply.");
A different solution to sending a reply is to provide the replyDestination object in the same Exchange property when sending. Camel will then pick up this property and use it for the real destination. The endpoint URI must include a dummy destination, however. For example:
// we pretend to send it to some non existing dummy queue
template.send("activemq:queue:dummy, new Processor() {
public void process(Exchange exchange) throws Exception {
// and here we override the destination with the ReplyTo destination object so the message is sent to there instead of dummy
exchange.getIn().setHeader(JmsConstants.JMS_DESTINATION, replyDestination);
exchange.getIn().setBody("Here is the late reply.");
}
}
Using a request timeoutIn the sample below we send a Request Reply style message Exchange (we use the requestBody method = InOut) to the slow queue for further processing in Camel and we wait for a return reply: // send a in-out with a timeout for 5 sec Object out = template.requestBody("activemq:queue:slow?requestTimeout=5000", "Hello World"); SamplesJMS is used in many examples for other components as well. But we provide a few samples below to get started. Receiving from JMSIn the following sample we configure a route that receives JMS messages and routes the message to a POJO: from("jms:queue:foo"). to("bean:myBusinessLogic"); You can of course use any of the EIP patterns so the route can be context based. For example, here's how to filter an order topic for the big spenders: from("jms:topic:OrdersTopic"). filter().method("myBean", "isGoldCustomer"). to("jms:queue:BigSpendersQueue"); Sending to a JMSIn the sample below we poll a file folder and send the file content to a JMS topic. As we want the content of the file as a TextMessage instead of a BytesMessage, we need to convert the body to a String: from("file://orders"). convertBodyTo(String.class). to("jms:topic:OrdersTopic"); Using AnnotationsCamel also has annotations so you can use POJO Consuming and POJO Producing. Spring DSL sampleThe preceding examples use the Java DSL. Camel also supports Spring XML DSL. Here is the big spender sample using Spring DSL: <route> <from uri="jms:topic:OrdersTopic"/> <filter> <method bean="myBean" method="isGoldCustomer"/> <to uri="jms:queue:BigSpendersQueue"/> </filter> </route> Other samplesJMS appears in many of the examples for other components and EIP patterns, as well in this Camel documentation. So feel free to browse the documentation. If you have time, check out the this tutorial that uses JMS but focuses on how well Spring Remoting and Camel works together Tutorial-JmsRemoting. Using JMS as a Dead Letter Queue storing ExchangeNormally, when using JMS as the transport, it only transfers the body and headers as the payload. If you want to use JMS with a Dead Letter Channel, using a JMS queue as the Dead Letter Queue, then normally the caused Exception is not stored in the JMS message. You can, however, use the transferExchange option on the JMS dead letter queue to instruct Camel to store the entire Exchange in the queue as a javax.jms.ObjectMessage that holds a org.apache.camel.impl.DefaultExchangeHolder. This allows you to consume from the Dead Letter Queue and retrieve the caused exception from the Exchange property with the key Exchange.EXCEPTION_CAUGHT. The demo below illustrates this: // setup error handler to use JMS as queue and store the entire Exchange errorHandler(deadLetterChannel("jms:queue:dead?transferExchange=true")); Then you can consume from the JMS queue and analyze the problem: from("jms:queue:dead").to("bean:myErrorAnalyzer"); // and in our bean String body = exchange.getIn().getBody(); Exception cause = exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class); // the cause message is String problem = cause.getMessage(); Using JMS as a Dead Letter Channel storing error onlyYou can use JMS to store the cause error message or to store a custom body, which you can initialize yourself. The following example uses the Message Translator EIP to do a transformation on the failed exchange before it is moved to the JMS dead letter queue: // we sent it to a seda dead queue first errorHandler(deadLetterChannel("seda:dead")); // and on the seda dead queue we can do the custom transformation before its sent to the JMS queue from("seda:dead").transform(exceptionMessage()).to("jms:queue:dead"); Here we only store the original cause error message in the transform. You can, however, use any Expression to send whatever you like. For example, you can invoke a method on a Bean or use a custom processor. Sending an InOnly message and keeping the JMSReplyTo headerWhen sending to a JMS destination using camel-jms the producer will use the MEP to detect if its InOnly or InOut messaging. However there can be times where you want to send an InOnly message but keeping the JMSReplyTo header. To do so you have to instruct Camel to keep it, otherwise the JMSReplyTo header will be dropped. For example to send an InOnly message to the foo queue, but with a JMSReplyTo with bar queue you can do as follows:
template.send("activemq:queue:foo?preserveMessageQos=true", new Processor() {
public void process(Exchange exchange) throws Exception {
exchange.getIn().setBody("World");
exchange.getIn().setHeader("JMSReplyTo", "bar");
}
});
Notice we use preserveMessageQos=true to instruct Camel to keep the JMSReplyTo header. Setting JMS provider options on the destinationSome JMS providers, like IBM's WebSphere MQ need options to be set on the JMS destination. For example, you may need to specify the targetClient option. Since targetClient is a WebSphere MQ option and not a Camel URI option, you need to set that on the JMS destination name like so: ... .setHeader("CamelJmsDestinationName", constant("queue:///MY_QUEUE?targetClient=1")) .to("wmq:queue:MY_QUEUE?useMessageIDAsCorrelationID=true"); Some versions of WMQ won't accept this option on the destination name and you will get an exception like:
A workaround is to use a custom DestinationResolver: JmsComponent wmq = new JmsComponent(connectionFactory); wmq.setDestinationResolver(new DestinationResolver(){ public Destination resolveDestinationName(Session session, String destinationName, boolean pubSubDomain) throws JMSException { MQQueueSession wmqSession = (MQQueueSession) session; return wmqSession.createQueue("queue:///" + destinationName + "?targetClient=1"); } }); See AlsoJMX ComponentAvailable as of Camel 2.6 Standard JMX Consumer ConfigurationComponent allows consumers to subscribe to an mbean's Notifications. The component supports passing the Notification object directly through the Exchange or serializing it to XML according to the schema provided within this project. This is a consumer only component. Exceptions are thrown if you attempt to create a producer for it. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jmx</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI FormatThe component can connect to the local platform mbean server with the following URI:
jmx://platform?options
A remote mbean server url can be provided following the initial JMX scheme like so:
jmx:service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi?options
You can append query options to the URI in the following format, ?options=value&option2=value&... URI Options
ObjectName ConstructionThe URI must always have the objectDomain property. In addition, the URI must contain either objectName or one or more properties that start with "key." Domain with Name propertyWhen the objectName property is provided, the following constructor is used to build the ObjectName? for the mbean: ObjectName(String domain, String key, String value) The key value in the above will be "name" and the value will be the value of the objectName property. Domain with HashtableObjectName(String domain, Hashtable<String,String> table) The Hashtable is constructed by extracting properties that start with "key." The properties will have the "key." prefixed stripped prior to building the Hashtable. This allows the URI to contain a variable number of properties to identify the mbean. Examplefrom("jmx:platform?objectDomain=jmxExample&key.name=simpleBean"). to("log:jmxEvent"); Monitor Type ConsumerAvailable as of Camel 2.8 CounterMonitor monitor = new CounterMonitor(); monitor.addObservedObject(makeObjectName("simpleBean")); monitor.setObservedAttribute("MonitorNumber"); monitor.setNotify(true); monitor.setInitThreshold(1); monitor.setGranularityPeriod(500); registerBean(monitor, makeObjectName("counter")); monitor.start(); The 2.8 version introduces a new type of consumer that automatically creates and registers a monitor bean for the specified objectName and attribute. Additional endpoint attributes allow the user to specify the attribute to monitor, type of monitor to create, and any other required properties. The code snippet above is condensed into a set of endpoint properties. The consumer uses these properties to create the CounterMonitor, register it, and then subscribe to its changes. All of the JMX monitor types are supported. Examplefrom("jmx:platform?objectDomain=myDomain&objectName=simpleBean&" + "monitorType=counter&observedAttribute=MonitorNumber&initThreshold=1&" + "granularityPeriod=500").to("mock:sink"); The example above will cause a new Monitor Bean to be created and depoyed to the local mbean server that monitors the "MonitorNumber" attribute on the "simpleBean." Additional types of monitor beans and options are detailed below. The newly deployed monitor bean is automatically undeployed when the consumer is stopped. URI Options for Monitor Type
The monitor style consumer is only supported for the local mbean server. JMX does not currently support remote deployment of mbeans without either having the classes already remotely deployed or an adapter library on both the client and server to facilitate a proxy deployment. See AlsoJPA ComponentThe jpa component enables you to store and retrieve Java objects from persistent storage using EJB 3's Java Persistence Architecture (JPA), which is a standard interface layer that wraps Object/Relational Mapping (ORM) products such as OpenJPA, Hibernate, TopLink, and so on. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jpa</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> Sending to the endpointYou can store a Java entity bean in a database by sending it to a JPA producer endpoint. The body of the In message is assumed to be an entity bean (that is, a POJO with an @Entity annotation on it) or a collection or array of entity beans. If the body does not contain one of the previous listed types, put a Message Translator in front of the endpoint to perform the necessary conversion first. Consuming from the endpointConsuming messages from a JPA consumer endpoint removes (or updates) entity beans in the database. This allows you to use a database table as a logical queue: consumers take messages from the queue and then delete/update them to logically remove them from the queue. If you do not wish to delete the entity bean when it has been processed, you can specify consumeDelete=false on the URI. This will result in the entity being processed each poll. If you would rather perform some update on the entity to mark it as processed (such as to exclude it from a future query) then you can annotate a method with @Consumed which will be invoked on your entity bean when the entity bean is consumed. URI formatjpa:[entityClassName][?options] For sending to the endpoint, the entityClassName is optional. If specified, it helps the Type Converter to ensure the body is of the correct type. For consuming, the entityClassName is mandatory. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Message HeadersCamel adds the following message headers to the exchange:
Configuring EntityManagerFactoryIts strongly advised to configure the JPA component to use a specific EntityManagerFactory instance. If failed to do so each JpaEndpoint will auto create their own instance of EntityManagerFactory which most often is not what you want. For example, you can instantiate a JPA component that references the myEMFactory entity manager factory, as follows: <bean id="jpa" class="org.apache.camel.component.jpa.JpaComponent"> <property name="entityManagerFactory" ref="myEMFactory"/> </bean> In Camel 2.3 the JpaComponent will auto lookup the EntityManagerFactory from the Registry which means you do not need to configure this on the JpaComponent as shown above. You only need to do so if there is ambiguity, in which case Camel will log a WARN. Configuring TransactionManagerIts strongly advised to configure the TransactionManager instance used by the JPA component. If failed to do so each JpaEndpoint will auto create their own instance of TransactionManager which most often is not what you want. For example, you can instantiate a JPA component that references the myTransactionManager transaction manager, as follows: <bean id="jpa" class="org.apache.camel.component.jpa.JpaComponent"> <property name="entityManagerFactory" ref="myEMFactory"/> <property name="transactionManager" ref="myTransactionManager"/> </bean> In Camel 2.3 the JpaComponent will auto lookup the TransactionManager from the Registry which means you do not need to configure this on the JpaComponent as shown above. You only need to do so if there is ambiguity, in which case Camel will log a WARN. Using a consumer with a named queryFor consuming only selected entities, you can use the consumer.namedQuery URI query option. First, you have to define the named query in the JPA Entity class: @Entity @NamedQuery(name = "step1", query = "select x from MultiSteps x where x.step = 1") public class MultiSteps { ... } After that you can define a consumer uri like this one: from("jpa://org.apache.camel.examples.MultiSteps?consumer.namedQuery=step1") .to("bean:myBusinessLogic"); Using a consumer with a queryFor consuming only selected entities, you can use the consumer.query URI query option. You only have to define the query option: from("jpa://org.apache.camel.examples.MultiSteps?consumer.query=select o from org.apache.camel.examples.MultiSteps o where o.step = 1") .to("bean:myBusinessLogic"); Using a consumer with a native queryFor consuming only selected entities, you can use the consumer.nativeQuery URI query option. You only have to define the native query option: from("jpa://org.apache.camel.examples.MultiSteps?consumer.nativeQuery=select * from MultiSteps where step = 1") .to("bean:myBusinessLogic"); If you use the native query option, you will receive an object array in the message body. ExampleSee Tracer Example for an example using JPA to store traced messages into a database. Using the JPA based idempotent repositoryIn this section we will use the JPA based idempotent repository. First we need to setup a persistence-unit in the persistence.xml file: <persistence-unit name="idempotentDb" transaction-type="RESOURCE_LOCAL"> <class>org.apache.camel.processor.idempotent.jpa.MessageProcessed</class> <properties> <property name="openjpa.ConnectionURL" value="jdbc:derby:target/idempotentTest;create=true"/> <property name="openjpa.ConnectionDriverName" value="org.apache.derby.jdbc.EmbeddedDriver"/> <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema"/> <property name="openjpa.Log" value="DefaultLevel=WARN, Tool=INFO"/> </properties> </persistence-unit> Second we have to setup a org.springframework.orm.jpa.JpaTemplate which is used by the org.apache.camel.processor.idempotent.jpa.JpaMessageIdRepository: <!-- this is standard spring JPA configuration --> <bean id="jpaTemplate" class="org.springframework.orm.jpa.JpaTemplate"> <property name="entityManagerFactory" ref="entityManagerFactory"/> </bean> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean"> <!-- we use idempotentDB as the persitence unit name defined in the persistence.xml file --> <property name="persistenceUnitName" value="idempotentDb"/> </bean> Afterwards we can configure our org.apache.camel.processor.idempotent.jpa.JpaMessageIdRepository: <!-- we define our jpa based idempotent repository we want to use in the file consumer --> <bean id="jpaStore" class="org.apache.camel.processor.idempotent.jpa.JpaMessageIdRepository"> <!-- Here we refer to the spring jpaTemplate --> <constructor-arg index="0" ref="jpaTemplate"/> <!-- This 2nd parameter is the name (= a cateogry name). You can have different repositories with different names --> <constructor-arg index="1" value="FileConsumer"/> </bean> And finally we can create our JPA idempotent repository in the spring XML file as well: <camel:camelContext> <camel:route id="JpaMessageIdRepositoryTest"> <camel:from uri="direct:start" /> <camel:idempotentConsumer messageIdRepositoryRef="jpaStore"> <camel:header>messageId</camel:header> <camel:to uri="mock:result" /> </camel:idempotentConsumer> </camel:route> </camel:camelContext> See AlsoJT/400 ComponentThe jt400 component allows you to exchanges messages with an AS/400 system using data queues. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-jt400</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
jt400://user:password@system/QSYS.LIB/LIBRARY.LIB/QUEUE.DTAQ[?options]
To call remote program (Camel 2.7)
jt400://user:password@system/QSYS.LIB/LIBRARY.LIB/program.PGM[?options]
You can append query options to the URI in the following format, ?option=value&option=value&... URI optionsFor the data queue message exchange:
For the remote program call (Camel 2.7)
UsageWhen configured as a consumer endpoint, the endpoint will poll a data queue on a remote system. For every entry on the data queue, a new Exchange is sent with the entry's data in the In message's body, formatted either as a String or a byte[], depending on the format. For a provider endpoint, the In message body contents will be put on the data queue as either raw bytes or text. Remote program call (Camel 2.7)This endpoint expects the input to be a String array and handles all the CCSID handling trough the native jt400 library mechanisms. After the program execution the endpoint returns a String array with the values as they were returned by the program (the input only parameters will contain the same data as the beginning of the invocation) ExampleIn the snippet below, the data for an exchange sent to the direct:george endpoint will be put in the data queue PENNYLANE in library BEATLES on a system named LIVERPOOL. public class Jt400RouteBuilder extends RouteBuilder { @Override public void configure() throws Exception { from("direct:george").to("jt400://GEORGE:EGROEG@LIVERPOOL/QSYS.LIB/BEATLES.LIB/PENNYLANE.DTAQ"); from("jt400://RINGO:OGNIR@LIVERPOOL/QSYS.LIB/BEATLES.LIB/PENNYLANE.DTAQ").to("mock:ringo"); } } Remote program call example (Camel 2.7)In the snippet below, the data Exchange sent to the direct:work endpoint will contain three string that will be used as the arguments for the program “compute” in the library “assets”. This program will write the output values in the 2nd and 3rd parameters. All the parameters will be sent to the direct:play endpoint. public class Jt400RouteBuilder extends RouteBuilder { @Override public void configure() throws Exception { from("direct:work").to("jt400://GRUPO:ATWORK@server/QSYS.LIB/assets.LIB/compute.PGM?fieldsLength=10,10,512&ouputFieldsIdx=2,3").to(“direct:play”); } } See AlsoLanguageAvailable as of Camel 2.5 The language component allows you to send Exchange to an endpoint which executes a script by any of the supported Languages in Camel. This component is provided out of the box in camel-core and hence no additional JARs is needed. You only have to include additional Camel components if the language of choice mandates it, such as using Groovy or JavaScript languages. URI format
language://languageName[:script][?options]
URI OptionsThe component supports the following options.
Message HeadersThe following message headers can be used to affect the behavior of the component
ExamplesFor example you can use the Simple language to Message Translator a message: String script = URLEncoder.encode("Hello ${body}", "UTF-8"); from("direct:start").to("language:simple:" + script).to("mock:result"); In case you want to convert the message body type you can do this as well: String script = URLEncoder.encode("${mandatoryBodyAs(String)}", "UTF-8"); from("direct:start").to("language:simple:" + script).to("mock:result"); You can also use the Groovy language, such as this example where the input message will by multiplied with 2: String script = URLEncoder.encode("request.body * 2", "UTF-8"); from("direct:start").to("language:groovy:" + script).to("mock:result"); You can also provide the script as a header as shown below. Here we use XPath language to extract the text from the <foo> tag. Object out = producer.requestBodyAndHeader("language:xpath", "<foo>Hello World</foo>", Exchange.LANGUAGE_SCRIPT, "/foo/text()"); assertEquals("Hello World", out); Loading scripts from resourcesAvailable as of Camel 2.9 You can specify a resource uri for a script to load in either the endpoint uri, or in the Exchange.LANGUAGE_SCRIPT header. For example to load a script from the classpath: from("direct:start") // load the script from the classpath .to("language:simple:classpath:org/apache/camel/component/language/mysimplescript.txt") .to("mock:result"); By default the script is loaded once and cached. However you can disable the contentCache option and have the script loaded on each evaluation. from("direct:start") // the script will be loaded on each message, as we disabled cache .to("language:simple:file:target/script/myscript.txt?contentCache=false") .to("mock:result"); See AlsoLDAP ComponentThe ldap component allows you to perform searches in LDAP servers using filters as the message payload. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-ldap</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatldap:ldapServerBean[?options] The ldapServerBean portion of the URI refers to a DirContext bean in the registry. The LDAP component only supports producer endpoints, which means that an ldap URI cannot appear in the from at the start of a route. You can append query options to the URI in the following format, ?option=value&option=value&... Options
ResultThe result is returned in the Out body as a ArrayList<javax.naming.directory.SearchResult> object. DirContextThe URI, ldap:ldapserver, references a Spring bean with the ID, ldapserver. The ldapserver bean may be defined as follows: <bean id="ldapserver" class="javax.naming.directory.InitialDirContext" scope="prototype"> <constructor-arg> <props> <prop key="java.naming.factory.initial">com.sun.jndi.ldap.LdapCtxFactory</prop> <prop key="java.naming.provider.url">ldap://localhost:10389</prop> <prop key="java.naming.security.authentication">none</prop> </props> </constructor-arg> </bean> The preceding example declares a regular Sun based LDAP DirContext that connects anonymously to a locally hosted LDAP server.
SamplesFollowing on from the Spring configuration above, the code sample below sends an LDAP request to filter search a group for a member. The Common Name is then extracted from the response.
ProducerTemplate<Exchange> template = exchange
.getContext().createProducerTemplate();
Collection<?> results = (Collection<?>) (template
.sendBody(
"ldap:ldapserver?base=ou=mygroup,ou=groups,ou=system",
"(member=uid=huntc,ou=users,ou=system)"));
if (results.size() > 0) {
// Extract what we need from the device's profile
Iterator<?> resultIter = results.iterator();
SearchResult searchResult = (SearchResult) resultIter
.next();
Attributes attributes = searchResult
.getAttributes();
Attribute deviceCNAttr = attributes.get("cn");
String deviceCN = (String) deviceCNAttr.get();
...
If no specific filter is required - for example, you just need to look up a single entry - specify a wildcard filter expression. For example, if the LDAP entry has a Common Name, use a filter expression like: (cn=*) Binding using credentialsA Camel end user donated this sample code he used to bind to the ldap server using credentials. Properties props = new Properties(); props.setProperty(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory"); props.setProperty(Context.PROVIDER_URL, "ldap://localhost:389"); props.setProperty(Context.URL_PKG_PREFIXES, "com.sun.jndi.url"); props.setProperty(Context.REFERRAL, "ignore"); props.setProperty(Context.SECURITY_AUTHENTICATION, "simple"); props.setProperty(Context.SECURITY_PRINCIPAL, "cn=Manager"); props.setProperty(Context.SECURITY_CREDENTIALS, "secret"); SimpleRegistry reg = new SimpleRegistry(); reg.put("myldap", new InitialLdapContext(props, null)); CamelContext context = new DefaultCamelContext(reg); context.addRoutes( new RouteBuilder() { public void configure() throws Exception { from("direct:start").to("ldap:myldap?base=ou=test"); } } ); context.start(); ProducerTemplate template = context.createProducerTemplate(); Endpoint endpoint = context.getEndpoint("direct:start"); Exchange exchange = endpoint.createExchange(); exchange.getIn().setBody("(uid=test)"); Exchange out = template.send(endpoint, exchange); Collection<SearchResult> data = out.getOut().getBody(Collection.class); assert data != null; assert !data.isEmpty(); System.out.println(out.getOut().getBody()); context.stop(); See AlsoLog ComponentThe log: component logs message exchanges to the underlying logging mechanism. Camel 2.7 or better uses sfl4j which allows you to configure logging via, among others:Camel 2.6 or lower uses commons-logging which allows you to configure logging via, among others:
Refer to the commons-logging user guide for a more complete overview of how to use and configure commons-logging. URI formatlog:loggingCategory[?options] Where loggingCategory is the name of the logging category to use. You can append query options to the URI in the following format, ?option=value&option=value&... For example, a log endpoint typically specifies the logging level using the level option, as follows: log:org.apache.camel.example?level=DEBUG The default logger logs every exchange (regular logging). But Camel also ships with the Throughput logger, which is used whenever the groupSize option is specified.
Options
note: groupDelay and groupActiveOnly are only applicable when using groupInterval FormattingThe log formats the execution of exchanges to log lines.
Regular logger sampleIn the route below we log the incoming orders at DEBUG level before the order is processed: from("activemq:orders").to("log:com.mycompany.order?level=DEBUG").to("bean:processOrder"); Or using Spring XML to define the route: <route> <from uri="activemq:orders"/> <to uri="log:com.mycompany.order?level=DEBUG"/> <to uri="bean:processOrder"/> </route> Regular logger with formatter sampleIn the route below we log the incoming orders at INFO level before the order is processed. from("activemq:orders"). to("log:com.mycompany.order?showAll=true&multiline=true").to("bean:processOrder"); Throughput logger with groupSize sampleIn the route below we log the throughput of the incoming orders at DEBUG level grouped by 10 messages. from("activemq:orders"). to("log:com.mycompany.order?level=DEBUG&groupSize=10").to("bean:processOrder"); Throughput logger with groupInterval sampleThis route will result in message stats logged every 10s, with an initial 60s delay and stats should be displayed even if there isn't any message traffic. from("activemq:orders"). to("log:com.mycompany.order?level=DEBUG&groupInterval=10000&groupDelay=60000&groupActiveOnly=false").to("bean:processOrder"); The following will be logged:
"Received: 1000 new messages, with total 2000 so far. Last group took: 10000 millis which is: 100 messages per second. average: 100"
See Also
Lucene (Indexer and Search) ComponentAvailable as of Camel 2.2 The lucene component is based on the Apache Lucene project. Apache Lucene is a powerful high-performance, full-featured text search engine library written entirely in Java. For more details about Lucene, please see the following links The lucene component in camel facilitates integration and utilization of Lucene endpoints in enterprise integration patterns and scenarios. The lucene component does the following
This component only supports producer endpoints. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-lucene</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatlucene:searcherName:insert[?options] lucene:searcherName:query[?options] You can append query options to the URI in the following format, ?option=value&option=value&... Insert Options
Query Options
Sending/Receiving Messages to/from the cacheMessage Headers
Lucene ProducersThis component supports 2 producer endpoints.
Lucene ProcessorThere is a processor called LuceneQueryProcessor available to perform queries against lucene without the need to create a producer. Lucene Usage SamplesExample 1: Creating a Lucene indexRouteBuilder builder = new RouteBuilder() { public void configure() { from("direct:start"). to("lucene:whitespaceQuotesIndex:insert? analyzer=#whitespaceAnalyzer&indexDir=#whitespace&srcDir=#load_dir"). to("mock:result"); } }; Example 2: Loading properties into the JNDI registry in the Camel Context@Override protected JndiRegistry createRegistry() throws Exception { JndiRegistry registry = new JndiRegistry(createJndiContext()); registry.bind("whitespace", new File("./whitespaceIndexDir")); registry.bind("load_dir", new File("src/test/resources/sources")); registry.bind("whitespaceAnalyzer", new WhitespaceAnalyzer()); return registry; } ... CamelContext context = new DefaultCamelContext(createRegistry()); Example 2: Performing searches using a Query ProducerRouteBuilder builder = new RouteBuilder() { public void configure() { from("direct:start"). setHeader("QUERY", constant("Seinfeld")). to("lucene:searchIndex:query? analyzer=#whitespaceAnalyzer&indexDir=#whitespace&maxHits=20"). to("direct:next"); from("direct:next").process(new Processor() { public void process(Exchange exchange) throws Exception { Hits hits = exchange.getIn().getBody(Hits.class); printResults(hits); } private void printResults(Hits hits) { LOG.debug("Number of hits: " + hits.getNumberOfHits()); for (int i = 0; i < hits.getNumberOfHits(); i++) { LOG.debug("Hit " + i + " Index Location:" + hits.getHit().get(i).getHitLocation()); LOG.debug("Hit " + i + " Score:" + hits.getHit().get(i).getScore()); LOG.debug("Hit " + i + " Data:" + hits.getHit().get(i).getData()); } } }).to("mock:searchResult"); } }; Example 3: Performing searches using a Query ProcessorRouteBuilder builder = new RouteBuilder() { public void configure() { try { from("direct:start"). setHeader("QUERY", constant("Rodney Dangerfield")). process(new LuceneQueryProcessor("target/stdindexDir", analyzer, null, 20)). to("direct:next"); } catch (Exception e) { e.printStackTrace(); } from("direct:next").process(new Processor() { public void process(Exchange exchange) throws Exception { Hits hits = exchange.getIn().getBody(Hits.class); printResults(hits); } private void printResults(Hits hits) { LOG.debug("Number of hits: " + hits.getNumberOfHits()); for (int i = 0; i < hits.getNumberOfHits(); i++) { LOG.debug("Hit " + i + " Index Location:" + hits.getHit().get(i).getHitLocation()); LOG.debug("Hit " + i + " Score:" + hits.getHit().get(i).getScore()); LOG.debug("Hit " + i + " Data:" + hits.getHit().get(i).getData()); } } }).to("mock:searchResult"); } }; Mail ComponentThe mail component provides access to Email via Spring's Mail support and the underlying JavaMail system. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-mail</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
URI formatMail endpoints can have one of the following URI formats (for the protocols, SMTP, POP3, or IMAP, respectively): smtp://[username@]host[:port][?options] pop3://[username@]host[:port][?options] imap://[username@]host[:port][?options] The mail component also supports secure variants of these protocols (layered over SSL). You can enable the secure protocols by adding s to the scheme: smtps://[username@]host[:port][?options] pop3s://[username@]host[:port][?options] imaps://[username@]host[:port][?options] You can append query options to the URI in the following format, ?option=value&option=value&... Sample endpointsTypically, you specify a URI with login credentials as follows (taking SMTP as an example):
smtp://[username@]host[:port][?password=somepwd]
Alternatively, it is possible to specify both the user name and the password as query options:
smtp://host[:port]?password=somepwd&username=someuser
For example:
smtp://mycompany.mailserver:30?password=tiger&username=scott
Default portsAs of Camel 1.4, default port numbers are supported. If the port number is omitted, Camel determines the port number to use based on the protocol.
Options
SSL supportThe underlying mail framework is responsible for providing SSL support. Camel uses SUN JavaMail, which only trusts certificates issued by well known Certificate Authorities. So if you issue your own certificate, you have to import it into the local Java keystore file (see SSLNOTES.txt in JavaMail for details). Defaults changed in Camel 1.4As of Camel 1.4 the default consumer delay is now 60 seconds. Camel will therefore only poll the mailbox once a minute to avoid overloading the mail server. The default value in Camel 1.3 is 500 milliseconds. Defaults changed in Camel 1.5In Camel 1.5 the following default options have changed:
Mail Message ContentCamel uses the message exchange's IN body as the MimeMessage text content. The body is converted to String.class. Camel copies all of the exchange's IN headers to the MimeMessage headers. The subject of the MimeMessage can be configured using a header property on the IN message. The code below demonstrates this: from("direct:a").setHeader("subject", constant(subject)).to("smtp://james2@localhost"); The same applies for other MimeMessage headers such as recipients, so you can use a header property as To: Map<String, Object> map = new HashMap<String, Object>(); map.put("To", "davsclaus@apache.org"); map.put("From", "jstrachan@apache.org"); map.put("Subject", "Camel rocks"); String body = "Hello Claus.\nYes it does.\n\nRegards James."; template.sendBodyAndHeaders("smtp://davsclaus@apache.org", body, map); Headers take precedence over pre-configured recipientsFrom Camel 1.5 onwards, the recipients specified in the message headers always take precedence over recipients pre-configured in the endpoint URI. The idea is that if you provide any recipients in the message headers, that is what you get. The recipients pre-configured in the endpoint URI are treated as a fallback. In the sample code below, the email message is sent to davsclaus@apache.org, because it takes precedence over the pre-configured recipient, info@mycompany.com. Any CC and BCC settings in the endpoint URI are also ignored and those recipients will not receive any mail. The choice between headers and pre-configured settings is all or nothing: the mail component either takes the recipients exclusively from the headers or exclusively from the pre-configured settings. It is not possible to mix and match headers and pre-configured settings.
Map<String, Object> headers = new HashMap<String, Object>();
headers.put("to", "davsclaus@apache.org");
template.sendBodyAndHeaders("smtp://admin@localhost?to=info@mycompany.com", "Hello World", headers);
Multiple recipients for easier configurationAs of Camel 1.5, it is possible to set multiple recipients using a comma-separated or a semicolon-separated list. This applies both to header settings and to settings in an endpoint URI. For example:
Map<String, Object> headers = new HashMap<String, Object>();
headers.put("to", "davsclaus@apache.org ; jstrachan@apache.org ; ningjiang@apache.org");
The preceding example uses a semicolon, ;, as the separator character. Setting sender name and emailYou can specify recipients in the format, name <email>, to include both the name and the email address of the recipient. For example, you define the following headers on the a Message: Map headers = new HashMap(); map.put("To", "Claus Ibsen <davsclaus@apache.org>"); map.put("From", "James Strachan <jstrachan@apache.org>"); map.put("Subject", "Camel is cool"); SUN JavaMailSUN JavaMail is used under the hood for consuming and producing mails.
SamplesWe start with a simple route that sends the messages received from a JMS queue as emails. The email account is the admin account on mymailserver.com.
from("jms://queue:subscription").to("smtp://admin@mymailserver.com?password=secret");
In the next sample, we poll a mailbox for new emails once every minute. Notice that we use the special consumer option for setting the poll interval, consumer.delay, as 60000 milliseconds = 60 seconds.
from("imap://admin@mymailserver.com
password=secret&unseen=true&consumer.delay=60000")
.to("seda://mails");
In this sample we want to send a mail to multiple recipients. This feature was introduced in camel 1.4: // all the recipients of this mail are: // To: camel@riders.org , easy@riders.org // CC: me@you.org // BCC: someone@somewhere.org String recipients = "&To=camel@riders.org,easy@riders.org&CC=me@you.org&BCC=someone@somewhere.org"; from("direct:a").to("smtp://you@mymailserver.com?password=secret&From=you@apache.org" + recipients); Sending mail with attachment sample
The mail component supports attachments, which is a feature that was introduced in Camel 1.4. In the sample below, we send a mail message containing a plain text message with a logo file attachment. // create an exchange with a normal body and attachment to be produced as email Endpoint endpoint = context.getEndpoint("smtp://james@mymailserver.com?password=secret"); // create the exchange with the mail message that is multipart with a file and a Hello World text/plain message. Exchange exchange = endpoint.createExchange(); Message in = exchange.getIn(); in.setBody("Hello World"); in.addAttachment("logo.jpeg", new DataHandler(new FileDataSource("src/test/data/logo.jpeg"))); // create a producer that can produce the exchange (= send the mail) Producer producer = endpoint.createProducer(); // start the producer producer.start(); // and let it go (processes the exchange by sending the email) producer.process(exchange); SSL sampleIn this sample, we want to poll our Google mail inbox for mails. To download mail onto a local mail client, Google mail requires you to enable and configure SSL. This is done by logging into your Google mail account and changing your settings to allow IMAP access. Google have extensive documentation on how to do this. from("imaps://imap.gmail.com?username=YOUR_USERNAME@gmail.com&password=YOUR_PASSWORD" + "&delete=false&unseen=true&consumer.delay=60000").to("log:newmail"); The preceding route polls the Google mail inbox for new mails once every minute and logs the received messages to the newmail logger category. 2008-05-08 06:32:09,640 DEBUG MailConsumer - Connecting to MailStore imaps//imap.gmail.com:993 (SSL enabled), folder=INBOX 2008-05-08 06:32:11,203 DEBUG MailConsumer - Polling mailfolder: imaps//imap.gmail.com:993 (SSL enabled), folder=INBOX 2008-05-08 06:32:11,640 DEBUG MailConsumer - Fetching 1 messages. Total 1 messages. 2008-05-08 06:32:12,171 DEBUG MailConsumer - Processing message: messageNumber=[332], from=[James Bond <007@mi5.co.uk>], to=YOUR_USERNAME@gmail.com], subject=[... 2008-05-08 06:32:12,187 INFO newmail - Exchange[MailMessage: messageNumber=[332], from=[James Bond <007@mi5.co.uk>], to=YOUR_USERNAME@gmail.com], subject=[... Consuming mails with attachment sampleIn this sample we poll a mailbox and store all attachments from the mails as files. First, we define a route to poll the mailbox. As this sample is based on google mail, it uses the same route as shown in the SSL sample: from("imaps://imap.gmail.com?username=YOUR_USERNAME@gmail.com&password=YOUR_PASSWORD" + "&delete=false&unseen=true&consumer.delay=60000").process(new MyMailProcessor()); Instead of logging the mail we use a processor where we can process the mail from java code:
public void process(Exchange exchange) throws Exception {
// the API is a bit clunky so we need to loop
Map<String, DataHandler> attachments = exchange.getIn().getAttachments();
if (attachments.size() > 0) {
for (String name : attachments.keySet()) {
DataHandler dh = attachments.get(name);
// get the file name
String filename = dh.getName();
// get the content and convert it to byte[]
byte[] data = exchange.getContext().getTypeConverter()
.convertTo(byte[].class, dh.getInputStream());
// write the data to a file
FileOutputStream out = new FileOutputStream(filename);
out.write(data);
out.flush();
out.close();
}
}
}
As you can see the API to handle attachments is a bit clunky but it's there so you can get the javax.activation.DataHandler so you can handle the attachments using standard API. See AlsoMINA ComponentThe mina: component is a transport for working with Apache MINA Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-mina</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatmina:tcp://hostname[:port][?options] mina:udp://hostname[:port][?options] mina:vm://hostname[:port][?options] From Camel 1.3 onwards you can specify a codec in the Registry using the codec option. If you are using TCP and no codec is specified then the textline flag is used to determine if text line based codec or object serialization should be used instead. By default the object serialization is used. For UDP if no codec is specified the default uses a basic ByteBuffer based codec. The VM protocol is used as a direct forwarding mechanism in the same JVM. See the MINA VM-Pipe API documentation for details. A Mina producer has a default timeout value of 30 seconds, while it waits for a response from the remote server. In normal use, camel-mina only supports marshalling the body content—message headers and exchange properties are not sent. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Default behavior changedIn Camel 2.0 the codec option must use # notation for lookup of the codec bean in the Registry. In Camel 1.5 the sync option has changed its default value from false to true, as we felt it was confusing for end-users when they used MINA to call remote servers and Camel wouldn't wait for the response. In Camel 1.4 or later codec=textline is no longer supported. Use the textline=true option instead. Using a custom codecSee the Mina documentation how to write your own codec. To use your custom codec with camel-mina, you should register your codec in the Registry; for example, by creating a bean in the Spring XML file. Then use the codec option to specify the bean ID of your codec. See HL7 that has a custom codec. Sample with sync=falseIn this sample, Camel exposes a service that listens for TCP connections on port 6200. We use the textline codec. In our route, we create a Mina consumer endpoint that listens on port 6200: from("mina:tcp://localhost:" + port1 + "?textline=true&sync=false").to("mock:result");
As the sample is part of a unit test, we test it by sending some data to it on port 6200. MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedBodiesReceived("Hello World"); template.sendBody("mina:tcp://localhost:" + port1 + "?textline=true&sync=false", "Hello World"); assertMockEndpointsSatisfied(); Sample with sync=trueIn the next sample, we have a more common use case where we expose a TCP service on port 6201 also use the textline codec. However, this time we want to return a response, so we set the sync option to true on the consumer. from("mina:tcp://localhost:" + port2 + "?textline=true&sync=true").process(new Processor() { public void process(Exchange exchange) throws Exception { String body = exchange.getIn().getBody(String.class); exchange.getOut().setBody("Bye " + body); } }); Then we test the sample by sending some data and retrieving the response using the template.requestBody() method. As we know the response is a String, we cast it to String and can assert that the response is, in fact, something we have dynamically set in our processor code logic. String response = (String)template.requestBody("mina:tcp://localhost:" + port2 + "?textline=true&sync=true", "World"); assertEquals("Bye World", response); Sample with Spring DSLSpring DSL can, of course, also be used for MINA. In the sample below we expose a TCP server on port 5555: <route> <from uri="mina:tcp://localhost:5555?textline=true"/> <to uri="bean:myTCPOrderHandler"/> </route> In the route above, we expose a TCP server on port 5555 using the textline codec. We let the Spring bean with ID, myTCPOrderHandler, handle the request and return a reply. For instance, the handler bean could be implemented as follows:
public String handleOrder(String payload) {
...
return "Order: OK"
}
Configuring Mina endpoints using Spring bean styleAvailable as of Camel 2.0 Configuration of Mina endpoints is now possible using regular Spring bean style configuration in the Spring DSL. However, in the underlying Apache Mina toolkit, it is relatively difficult to set up the acceptor and the connector, because you can not use simple setters. To resolve this difficulty, we leverage the MinaComponent as a Spring factory bean to configure this for us. If you really need to configure this yourself, there are setters on the MinaEndpoint to set these when needed. The sample below shows the factory approach: <!-- Creating mina endpoints is a bit complex so we reuse MinaComponnet
as a factory bean to create our endpoint, this is the easiest to do -->
<bean id="myMinaFactory" class="org.apache.camel.component.mina.MinaComponent">
<!-- we must provide a camel context so we refer to it by its id -->
<constructor-arg index="0" ref="myCamel"/>
</bean>
<!-- This is our mina endpoint configured with spring, we will use the factory above
to create it for us. The goal is to invoke the createEndpoint method with the
mina configuration parameter we defined using the constructor-arg option -->
<bean id="myMinaEndpoint"
factory-bean="myMinaFactory"
factory-method="createEndpoint">
<!-- and here we can pass it our configuration -->
<constructor-arg index="0" ref="myMinaConfig"/>
</bean>
<!-- this is our mina configuration with plain properties -->
<bean id="myMinaConfig" class="org.apache.camel.component.mina.MinaConfiguration">
<property name="protocol" value="tcp"/>
<property name="host" value="localhost"/>
<property name="port" value="1234"/>
<property name="sync" value="false"/>
</bean>
And then we can refer to our endpoint directly in the route, as follows: <route> <!-- here we route from or mina endpoint we have defined above --> <from ref="myMinaEndpoint"/> <to uri="mock:result"/> </route> Closing Session When CompleteAvailable as of Camel 1.6.1 When acting as a server you sometimes want to close the session when, for example, a client conversion is finished. To instruct Camel to close the session, you should add a header with the key CamelMinaCloseSessionWhenComplete set to a boolean true value. For instance, the example below will close the session after it has written the bye message back to the client:
from("mina:tcp://localhost:8080?sync=true&textline=true").process(new Processor() {
public void process(Exchange exchange) throws Exception {
String body = exchange.getIn().getBody(String.class);
exchange.getOut().setBody("Bye " + body);
exchange.getOut().setHeader(MinaConstants.MINA_CLOSE_SESSION_WHEN_COMPLETE, true);
}
});
Get the IoSession for messageAvailable since Camel 2.1 Configuring Mina filtersAvailable since Camel 2.0 Filters permit you to use some Mina Filters, such as SslFilter. You can also implement some customized filters. Please note that codec and logger are also implemented as Mina filters of type, IoFilter. Any filters you may define are appended to the end of the filter chain; that is, after codec and logger. For instance, the example below will send a keep-alive message after 10 seconds of inactivity: public class KeepAliveFilter extends IoFilterAdapter { @Override public void sessionCreated(NextFilter nextFilter, IoSession session) throws Exception { session.setIdleTime(IdleStatus.BOTH_IDLE, 10); nextFilter.sessionCreated(session); } @Override public void sessionIdle(NextFilter nextFilter, IoSession session, IdleStatus status) throws Exception { session.write("NOOP"); // NOOP is a FTP command for keep alive nextFilter.sessionIdle(session, status); } } As Camel Mina may use a request-reply scheme, the endpoint as a client would like to drop some message, such as greeting when the connection is established. For example, when you connect to an FTP server, you will get a 220 message with a greeting (220 Welcome to Pure-FTPd). If you don't drop the message, your request-reply scheme will be broken. public class DropGreetingFilter extends IoFilterAdapter { @Override public void messageReceived(NextFilter nextFilter, IoSession session, Object message) throws Exception { if (message instanceof String) { String ftpMessage = (String) message; // "220" is given as greeting. "200 Zzz" is given as a response to "NOOP" (keep alive) if (ftpMessage.startsWith("220") || or ftpMessage.startsWith("200 Zzz")) { // Dropping greeting return; } } nextFilter.messageReceived(session, message); } } Then, you can configure your endpoint using Spring DSL: <bean id="myMinaFactory" class="org.apache.camel.component.mina.MinaComponent"> <constructor-arg index="0" ref="camelContext" /> </bean> <bean id="myMinaEndpoint" factory-bean="myMinaFactory" factory-method="createEndpoint"> <constructor-arg index="0" ref="myMinaConfig"/> </bean> <bean id="myMinaConfig" class="org.apache.camel.component.mina.MinaConfiguration"> <property name="protocol" value="tcp" /> <property name="host" value="localhost" /> <property name="port" value="2121" /> <property name="sync" value="true" /> <property name="minaLogger" value="true" /> <property name="filters" ref="listFilters"/> </bean> <bean id="listFilters" class="java.util.ArrayList" > <constructor-arg> <list value-type="org.apache.mina.common.IoFilter"> <bean class="com.example.KeepAliveFilter"/> <bean class="com.example.DropGreetingFilter"/> </list> </constructor-arg> </bean> See AlsoMock ComponentTesting of distributed and asynchronous processing is notoriously difficult. The Mock, Test and DataSet endpoints work great with the Camel Testing Framework to simplify your unit and integration testing using Enterprise Integration Patterns and Camel's large range of Components together with the powerful Bean Integration.The Mock component provides a powerful declarative testing mechanism, which is similar to jMock in that it allows declarative expectations to be created on any Mock endpoint before a test begins. Then the test is run, which typically fires messages to one or more endpoints, and finally the expectations can be asserted in a test case to ensure the system worked as expected. This allows you to test various things like:
Note that there is also the Test endpoint which is a Mock endpoint, but which uses a second endpoint to provide the list of expected message bodies and automatically sets up the Mock endpoint assertions. In other words, it's a Mock endpoint that automatically sets up its assertions from some sample messages in a File or database, for example.
URI formatmock:someName[?options] Where someName can be any string that uniquely identifies the endpoint. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Simple ExampleHere's a simple example of Mock endpoint in use. First, the endpoint is resolved on the context. Then we set an expectation, and then, after the test has run, we assert that our expectations have been met. MockEndpoint resultEndpoint = context.resolveEndpoint("mock:foo", MockEndpoint.class); resultEndpoint.expectedMessageCount(2); // send some messages ... // now lets assert that the mock:foo endpoint received 2 messages resultEndpoint.assertIsSatisfied(); You typically always call the assertIsSatisfied() method to test that the expectations were met after running a test. Camel will by default wait 10 seconds when the assertIsSatisfied() is invoked. This can be configured by setting the setResultWaitTime(millis) method. When the assertion is satisfied then Camel will stop waiting and continue from the assertIsSatisfied method. That means if a new message arrives on the mock endpoint, just a bit later, that arrival will not affect the outcome of the assertion. Suppose you do want to test that no new messages arrives after a period thereafter, then you can do that by setting the setAssertPeriod method. Using assertPeriodAvailable as of Camel 2.7 MockEndpoint resultEndpoint = context.resolveEndpoint("mock:foo", MockEndpoint.class); resultEndpoint.setAssertPeriod(5000); resultEndpoint.expectedMessageCount(2); // send some messages ... // now lets assert that the mock:foo endpoint received 2 messages resultEndpoint.assertIsSatisfied(); Setting expectationsYou can see from the javadoc of MockEndpoint the various helper methods you can use to set expectations. The main methods are as follows:
Here's another example: resultEndpoint.expectedBodiesReceived("firstMessageBody", "secondMessageBody", "thirdMessageBody"); Adding expectations to specific messagesIn addition, you can use the message(int messageIndex) method to add assertions about a specific message that is received. For example, to add expectations of the headers or body of the first message (using zero-based indexing like java.util.List), you can use the following code: resultEndpoint.message(0).header("foo").isEqualTo("bar"); There are some examples of the Mock endpoint in use in the camel-core processor tests. Mocking existing endpointsAvailable as of Camel 2.7 Camel now allows you to automatic mock existing endpoints in your Camel routes.
Suppose you have the given route below: Route @Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { from("direct:start").to("direct:foo").to("log:foo").to("mock:result"); from("direct:foo").transform(constant("Bye World")); } }; } You can then use the adviceWith feature in Camel to mock all the endpoints in a given route from your unit test, as shown below: adviceWith mocking all endpoints public void testAdvisedMockEndpoints() throws Exception { // advice the first route using the inlined AdviceWith route builder // which has extended capabilities than the regular route builder context.getRouteDefinitions().get(0).adviceWith(context, new AdviceWithRouteBuilder() { @Override public void configure() throws Exception { // mock all endpoints mockEndpoints(); } }); getMockEndpoint("mock:direct:start").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:direct:foo").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:log:foo").expectedBodiesReceived("Bye World"); getMockEndpoint("mock:result").expectedBodiesReceived("Bye World"); template.sendBody("direct:start", "Hello World"); assertMockEndpointsSatisfied(); // additional test to ensure correct endpoints in registry assertNotNull(context.hasEndpoint("direct:start")); assertNotNull(context.hasEndpoint("direct:foo")); assertNotNull(context.hasEndpoint("log:foo")); assertNotNull(context.hasEndpoint("mock:result")); // all the endpoints was mocked assertNotNull(context.hasEndpoint("mock:direct:start")); assertNotNull(context.hasEndpoint("mock:direct:foo")); assertNotNull(context.hasEndpoint("mock:log:foo")); } Notice that the mock endpoints is given the uri mock:<endpoint>, for example mock:direct:foo. Camel logs at INFO level the endpoints being mocked:
INFO Adviced endpoint [direct://foo] with mock endpoint [mock:direct:foo]
Its also possible to only mock certain endpoints using a pattern. For example to mock all log endpoints you do as shown: adviceWith mocking only log endpoints using a pattern public void testAdvisedMockEndpointsWithPattern() throws Exception { // advice the first route using the inlined AdviceWith route builder // which has extended capabilities than the regular route builder context.getRouteDefinitions().get(0).adviceWith(context, new AdviceWithRouteBuilder() { @Override public void configure() throws Exception { // mock only log endpoints mockEndpoints("log*"); } }); // now we can refer to log:foo as a mock and set our expectations getMockEndpoint("mock:log:foo").expectedBodiesReceived("Bye World"); getMockEndpoint("mock:result").expectedBodiesReceived("Bye World"); template.sendBody("direct:start", "Hello World"); assertMockEndpointsSatisfied(); // additional test to ensure correct endpoints in registry assertNotNull(context.hasEndpoint("direct:start")); assertNotNull(context.hasEndpoint("direct:foo")); assertNotNull(context.hasEndpoint("log:foo")); assertNotNull(context.hasEndpoint("mock:result")); // only the log:foo endpoint was mocked assertNotNull(context.hasEndpoint("mock:log:foo")); assertNull(context.hasEndpoint("mock:direct:start")); assertNull(context.hasEndpoint("mock:direct:foo")); } The pattern supported can be a wildcard or a regular expression. See more details about this at Intercept as its the same matching function used by Camel.
Mocking existing endpoints using the camel-test componentInstead of using the adviceWith to instruct Camel to mock endpoints, you can easily enable this behavior when using the camel-test Test Kit. isMockEndpoints using camel-test kit public class IsMockEndpointsJUnit4Test extends CamelTestSupport { @Override public String isMockEndpoints() { // override this method and return the pattern for which endpoints to mock. // use * to indicate all return "*"; } @Test public void testMockAllEndpoints() throws Exception { // notice we have automatic mocked all endpoints and the name of the endpoints is "mock:uri" getMockEndpoint("mock:direct:start").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:direct:foo").expectedBodiesReceived("Hello World"); getMockEndpoint("mock:log:foo").expectedBodiesReceived("Bye World"); getMockEndpoint("mock:result").expectedBodiesReceived("Bye World"); template.sendBody("direct:start", "Hello World"); assertMockEndpointsSatisfied(); // additional test to ensure correct endpoints in registry assertNotNull(context.hasEndpoint("direct:start")); assertNotNull(context.hasEndpoint("direct:foo")); assertNotNull(context.hasEndpoint("log:foo")); assertNotNull(context.hasEndpoint("mock:result")); // all the endpoints was mocked assertNotNull(context.hasEndpoint("mock:direct:start")); assertNotNull(context.hasEndpoint("mock:direct:foo")); assertNotNull(context.hasEndpoint("mock:log:foo")); } @Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { from("direct:start").to("direct:foo").to("log:foo").to("mock:result"); from("direct:foo").transform(constant("Bye World")); } }; } } Mocking existing endpoints with XML DSLIf you do not use the camel-test component for unit testing (as shown above) you can use a different approach when using XML files for routes. Suppose we have the route in the camel-route.xml file: camel-route.xml <!-- this camel route is in the camel-route.xml file --> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <to uri="direct:foo"/> <to uri="log:foo"/> <to uri="mock:result"/> </route> <route> <from uri="direct:foo"/> <transform> <constant>Bye World</constant> </transform> </route> </camelContext> Then we create a new XML file as follows, where we include the camel-route.xml file and define a spring bean with the class org.apache.camel.impl.InterceptSendToMockEndpointStrategy which tells Camel to mock all endpoints: test-camel-route.xml <!-- the Camel route is defined in another XML file --> <import resource="camel-route.xml"/> <!-- bean which enables mocking all endpoints --> <bean id="mockAllEndpoints" class="org.apache.camel.impl.InterceptSendToMockEndpointStrategy"/> Then in your unit test you load the new XML file (test-camel-route.xml) instead of camel-route.xml. To only mock all Log endpoints you can define the pattern in the constructor for the bean: <bean id="mockAllEndpoints" class="org.apache.camel.impl.InterceptSendToMockEndpointStrategy"> <constructor-arg index="0" value="log*"/> </bean> Testing with arrival timesAvailable as of Camel 2.7 The Mock endpoint stores the arrival time of the message as a property on the Exchange. Date time = exchange.getProperty(Exchange.RECEIVED_TIMESTAMP, Date.class); You can use this information to know when the message arrived on the mock. But it also provides foundation to know the time interval between the previous and next message arrived on the mock. You can use this to set expectations using the arrives DSL on the Mock endpoint. For example to say that the first message should arrive between 0-2 seconds before the next you can do: mock.message(0).arrives().noLaterThan(2).seconds().beforeNext(); You can also define this as that 2nd message (0 index based) should arrive no later than 0-2 seconds after the previous: mock.message(1).arrives().noLaterThan(2).seconds().afterPrevious(); You can also use between to set a lower bound. For example suppose that it should be between 1-4 seconds: mock.message(1).arrives().between(1, 4).seconds().afterPrevious(); You can also set the expectation on all messages, for example to say that the gap between them should be at most 1 second: mock.allMessages().arrives().noLaterThan(1).seconds().beforeNext();
See AlsoMSV ComponentThe MSV component performs XML validation of the message body using the MSV Library and any of the supported XML schema languages, such as XML Schema or RelaxNG XML Syntax. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-msv</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> Note that the Jing component also supports RelaxNG Compact Syntax URI formatmsv:someLocalOrRemoteResource[?options] Where someLocalOrRemoteResource is some URL to a local resource on the classpath or a full URL to a remote resource or resource on the file system. For example
msv:org/foo/bar.rng
msv:file:../foo/bar.rng
msv:http://acme.com/cheese.rng
You can append query options to the URI in the following format, ?option=value&option=value&... Options
ExampleThe following example shows how to configure a route from endpoint direct:start which then goes to one of two endpoints, either mock:valid or mock:invalid based on whether or not the XML matches the given RelaxNG XML Schema (which is supplied on the classpath). <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:start"/> <doTry> <to uri="msv:org/apache/camel/component/validator/msv/schema.rng"/> <to uri="mock:valid"/> <doCatch> <exception>org.apache.camel.ValidationException</exception> <to uri="mock:invalid"/> </doCatch> <doFinally> <to uri="mock:finally"/> </doFinally> </doTry> </route> </camelContext> See AlsoMyBatisAvailable as of Camel 2.7 The mybatis: component allows you to query, poll, insert, update and delete data in a relational database using MyBatis. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-mybatis</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatmybatis:statementName[?options] Where statementName is the statement name in the MyBatis XML mapping file which maps to the query, insert, update or delete operation you wish to evaluate. You can append query options to the URI in the following format, ?option=value&option=value&... This component will by default load the MyBatis SqlMapConfig file from the root of the classpath and expected named as SqlMapConfig.xml. Options
Message HeadersCamel will populate the result message, either IN or OUT with a header with the statement used:
Message BodyThe response from MyBatis will only be set as body if it's a SELECT statement. That means, for example, for INSERT statements Camel will not replace the body. This allows you to continue routing and keep the original body. The response from MyBatis is always stored in the header with the key CamelMyBatisResult. SamplesFor example if you wish to consume beans from a JMS queue and insert them into a database you could do the following: from("activemq:queue:newAccount"). to("mybatis:insertAccount?statementType=Insert"); Notice we have to specify the statementType, as we need to instruct Camel which kind of operation to invoke. Where insertAccount is the MyBatis ID in the SQL mapping file: <!-- Insert example, using the Account parameter class --> <insert id="insertAccount" parameterType="Account"> insert into ACCOUNT ( ACC_ID, ACC_FIRST_NAME, ACC_LAST_NAME, ACC_EMAIL ) values ( #{id}, #{firstName}, #{lastName}, #{emailAddress} ) </insert> Using StatementType for better control of MyBatisWhen routing to an MyBatis endpoint you want more fine grained control so you can control whether the SQL statement to be executed is a SELEECT, UPDATE, DELETE or INSERT etc. So for instance if we want to route to an MyBatis endpoint in which the IN body contains parameters to a SELECT statement we can do: from("direct:start") .to("mybatis:selectAccountById?statementType=SelectOne") .to("mock:result"); In the code above we can invoke the MyBatis statement selectAccountById and the IN body should contain the account id we want to retrieve, such as an Integer type. We can do the same for some of the other operations, such as SelectList: from("direct:start") .to("mybatis:selectAllAccounts?statementType=SelectList") .to("mock:result"); And the same for UPDATE, where we can send an Account object as IN body to MyBatis: from("direct:start") .to("mybatis:updateAccount?statementType=Update") .to("mock:result"); Scheduled polling exampleSince this component does not support scheduled polling, you need to use another mechanism for triggering the scheduled polls, such as the Timer or Quartz components. In the sample below we poll the database, every 30 seconds using the Timer component and send the data to the JMS queue:
from("timer://pollTheDatabase?delay=30000").to("mbatis:selectAllAccounts").to("activemq:queue:allAccounts");
And the MyBatis SQL mapping file used: <!-- Select with no parameters using the result map for Account class. --> <select id="selectAllAccounts" resultMap="AccountResult"> select * from ACCOUNT </select> Using onConsumeThis component supports executing statements after data have been consumed and processed by Camel. This allows you to do post updates in the database. Notice all statements must be UPDATE statements. Camel supports executing multiple statements whose name should be separated by comma. The route below illustrates we execute the consumeAccount statement data is processed. This allows us to change the status of the row in the database to processed, so we avoid consuming it twice or more. from("mybatis:selectUnprocessedAccounts?consumer.onConsume=consumeAccount").to("mock:results"); And the statements in the sqlmap file: <select id="selectUnprocessedAccounts" resultMap="AccountResult"> select * from ACCOUNT where PROCESSED = false </select> <update id="consumeAccount" parameterType="Account"> update ACCOUNT set PROCESSED = true where ACC_ID = #{id} </update> See AlsoNagiosAvailable as of Camel 2.3 The Nagios component allows you to send passive checks to Nagios. Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-nagios</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
URI format
nagios://host[:port][?Options]
Camel provides two abilities with the Nagios component. You can send passive check messages by sending a message to its endpoint. Options
Headers
Sending message examplesYou can send a message to Nagios where the message payload contains the message. By default it will be OK level and use the CamelContext name as the service name. You can overrule these values using headers as shown above. For example we send the Hello Nagios message to Nagios as follows:
template.sendBody("direct:start", "Hello Nagios");
from("direct:start").to("nagios:127.0.0.1:5667?password=secret").to("mock:result");
To send a CRITICAL message you can send the headers such as:
Map headers = new HashMap();
headers.put(NagiosConstants.LEVEL, "CRITICAL");
headers.put(NagiosConstants.HOST_NAME, "myHost");
headers.put(NagiosConstants.SERVICE_NAME, "myService");
template.sendBodyAndHeaders("direct:start", "Hello Nagios", headers);
Using NagiosEventNotiferThe Nagios component also provides an EventNotifer which you can use to send events to Nagios. For example we can enable this from Java as follows:
NagiosEventNotifier notifier = new NagiosEventNotifier();
notifier.getConfiguration().setHost("localhost");
notifier.getConfiguration().setPort(5667);
notifier.getConfiguration().setPassword("password");
CamelContext context = ...
context.getManagementStrategy().addEventNotifier(notifier);
return context;
In Spring XML its just a matter of defining a Spring bean with the type EventNotifier and Camel will pick it up as documented here: Advanced configuration of CamelContext using Spring. See AlsoNetty ComponentAvailable as of Camel 2.3 The netty component in Camel is a socket communication component, based on the JBoss Netty community offering (available under an Apache 2.0 license). This camel component supports both producer and consumer endpoints. The netty component has several options and allows fine-grained control of a number of TCP/UDP communication parameters (buffer sizes, keepAlives, tcpNoDelay etc) and facilitates both In-Only and In-Out communication on a Camel route. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-netty</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatThe URI scheme for a netty component is as follows netty:tcp://localhost:99999[?options] netty:udp://remotehost:99999/[?options] This component supports producer and consumer endpoints for both TCP and UDP. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Registry based OptionsCodec Handlers and SSL Keystores can be enlisted in the Registry, such as in the Spring XML file.
Sending Messages to/from a Netty endpointNetty ProducerIn Producer mode, the component provides the ability to send payloads to a socket endpoint The producer mode supports both one-way and request-response based operations. Netty ConsumerIn Consumer mode, the component provides the ability to:
The consumer mode supports both one-way and request-response based operations. Usage SamplesA UDP Netty endpoint using Request-Reply and serialized object payloadRouteBuilder builder = new RouteBuilder() { public void configure() { from("netty:udp://localhost:5155?sync=true") .process(new Processor() { public void process(Exchange exchange) throws Exception { Poetry poetry = (Poetry) exchange.getIn().getBody(); poetry.setPoet("Dr. Sarojini Naidu"); exchange.getOut().setBody(poetry); } } } }; A TCP based Netty consumer endpoint using One-way communicationRouteBuilder builder = new RouteBuilder() { public void configure() { from("netty:tcp://localhost:5150") .to("mock:result"); } }; An SSL/TCP based Netty consumer endpoint using Request-Reply communicationUsing the JSSE Configuration UtilityAs of Camel 2.9, the Netty component supports SSL/TLS configuration through the Camel JSSE Configuration Utility. This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the Netty component. Programmatic configuration of the componentKeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); NettyComponent nettyComponent = getContext().getComponent("netty", NettyComponent.class); nettyComponent.setSslContextParameters(scp); Spring DSL based configuration of endpoint
...
<camel:sslContextParameters
id="sslContextParameters">
<camel:keyManagers
keyPassword="keyPassword">
<camel:keyStore
resource="/users/home/server/keystore.jks"
password="keystorePassword"/>
</camel:keyManagers>
</camel:sslContextParameters>...
...
<to uri="netty:tcp://localhost:5150?sync=true&ssl=true&sslContextParameters=#sslContextParameters"/>
...
Using Basic SSL/TLS configuration on the Jetty ComponentJndiRegistry registry = new JndiRegistry(createJndiContext()); registry.bind("password", "changeit"); registry.bind("ksf", new File("src/test/resources/keystore.jks")); registry.bind("tsf", new File("src/test/resources/keystore.jks")); context.createRegistry(registry); context.addRoutes(new RouteBuilder() { public void configure() { String netty_ssl_endpoint = "netty:tcp://localhost:5150?sync=true&ssl=true&passphrase=#password" + "&keyStoreFile=#ksf&trustStoreFile=#tsf"; String return_string = "When You Go Home, Tell Them Of Us And Say," + "For Your Tomorrow, We Gave Our Today."; from(netty_ssl_endpoint) .process(new Processor() { public void process(Exchange exchange) throws Exception { exchange.getOut().setBody(return_string); } } } }); Using Multiple CodecsIn certain cases it may be necessary to add chains of encoders and decoders to the netty pipeline. To add multpile codecs to a camel netty endpoint the 'encoders' and 'decoders' uri parameters should be used. Like the 'encoder' and 'decoder' parameters they are used to supply references (to lists of ChannelUpstreamHandlers and ChannelDownstreamHandlers) that should be added to the pipeline. Note that if encoders is specified then the encoder param will be ignored, similarly for decoders and the decoder param. The lists of codecs need to be added to the Camel's registry so they can be resolved when the endpoint is created. LengthFieldBasedFrameDecoder lengthDecoder = new LengthFieldBasedFrameDecoder(1048576, 0, 4, 0, 4); StringDecoder stringDecoder = new StringDecoder(); registry.bind("length-decoder", lengthDecoder); registry.bind("string-decoder", stringDecoder); LengthFieldPrepender lengthEncoder = new LengthFieldPrepender(4); StringEncoder stringEncoder = new StringEncoder(); registry.bind("length-encoder", lengthEncoder); registry.bind("string-encoder", stringEncoder); List<ChannelUpstreamHandler> decoders = new ArrayList<ChannelUpstreamHandler>(); decoders.add(lengthDecoder); decoders.add(stringDecoder); List<ChannelDownstreamHandler> encoders = new ArrayList<ChannelDownstreamHandler>(); encoders.add(lengthEncoder); encoders.add(stringEncoder); registry.bind("encoders", encoders); registry.bind("decoders", decoders); Spring's native collections support can be used to specify the codec lists in an application context <util:list id="decoders" list-class="java.util.LinkedList"> <bean class="org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder"> <constructor-arg value="1048576"/> <constructor-arg value="0"/> <constructor-arg value="4"/> <constructor-arg value="0"/> <constructor-arg value="4"/> </bean> <bean class="org.jboss.netty.handler.codec.string.StringDecoder"/> </util:list> <util:list id="encoders" list-class="java.util.LinkedList"> <bean class="org.jboss.netty.handler.codec.frame.LengthFieldPrepender"> <constructor-arg value="4"/> </bean> <bean class="org.jboss.netty.handler.codec.string.StringEncoder"/> </util:list> <bean id="length-encoder" class="org.jboss.netty.handler.codec.frame.LengthFieldPrepender"> <constructor-arg value="4"/> </bean> <bean id="string-encoder" class="org.jboss.netty.handler.codec.string.StringEncoder"/> <bean id="length-decoder" class="org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder"> <constructor-arg value="1048576"/> <constructor-arg value="0"/> <constructor-arg value="4"/> <constructor-arg value="0"/> <constructor-arg value="4"/> </bean> <bean id="string-decoder" class="org.jboss.netty.handler.codec.string.StringDecoder"/> </beans> The bean names can then be used in netty endpoint definitions either as a comma separated list or contained in a List e.g. from("direct:multiple-codec").to("netty:tcp://localhost:{{port}}?encoders=#encoders&sync=false"); from("netty:tcp://localhost:{{port}}?decoders=#length-decoder,#string-decoder&sync=false").to("mock:multiple-codec"); } }; } } or via spring. <camelContext id="multiple-netty-codecs-context" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:multiple-codec"/> <to uri="netty:tcp://localhost:5150?encoders=#encoders&sync=false"/> </route> <route> <from uri="netty:tcp://localhost:5150?decoders=#length-decoder,#string-decoder&sync=false"/> <to uri="mock:multiple-codec"/> </route> </camelContext> Closing Channel When CompleteWhen acting as a server you sometimes want to close the channel when, for example, a client conversion is finished. However you can also instruct Camel on a per message basis as follows.
from("netty:tcp://localhost:8080").process(new Processor() {
public void process(Exchange exchange) throws Exception {
String body = exchange.getIn().getBody(String.class);
exchange.getOut().setBody("Bye " + body);
// some condition which determines if we should close
if (close) {
exchange.getOut().setHeader(NettyConstants.NETTY_CLOSE_CHANNEL_WHEN_COMPLETE, true);
}
}
});
Adding custom channel pipeline factories to gain complete control over a created pipelineAvailable as of Camel 2.5 Custom channel pipelines provide complete control to the user over the handler/interceptor chain by inserting custom handler(s), encoder(s) & decoders without having to specify them in the Netty Endpoint URL in a very simple way. In order to add a custom pipeline, a custom channel pipeline factory must be created and registered with the context via the context registry (JNDIRegistry,or the camel-spring ApplicationContextRegistry etc). A custom pipeline factory must be constructed as follows
The example below shows how ServerChannel Pipeline factory may be created public class SampleServerChannelPipelineFactory extends ServerPipelineFactory { private int maxLineSize = 1024; private boolean invoked; public ChannelPipeline getPipeline() throws Exception { invoked = true; ChannelPipeline channelPipeline = Channels.pipeline(); channelPipeline.addLast("encoder-SD", new StringEncoder(CharsetUtil.UTF_8)); channelPipeline.addLast("decoder-DELIM", new DelimiterBasedFrameDecoder(maxLineSize, true, Delimiters.lineDelimiter())); channelPipeline.addLast("decoder-SD", new StringDecoder(CharsetUtil.UTF_8)); channelPipeline.addLast("handler", new ServerChannelHandler(consumer)); return channelPipeline; } public boolean isfactoryInvoked() { return invoked; } } The custom channel pipeline factory can then be added to the registry and instantiated/utilized on a camel route in the following way Registry registry = camelContext.getRegistry(); serverPipelineFactory = new TestServerChannelPipelineFactory(); registry.bind("spf", serverPipelineFactory); context.addRoutes(new RouteBuilder() { public void configure() { String netty_ssl_endpoint = "netty:tcp://localhost:5150?serverPipelineFactory=#spf" String return_string = "When You Go Home, Tell Them Of Us And Say," + "For Your Tomorrow, We Gave Our Today."; from(netty_ssl_endpoint) .process(new Processor() { public void process(Exchange exchange) throws Exception { exchange.getOut().setBody(return_string); } } } }); See AlsoNMR ComponentThe nmr component is an adapter to the Normalized Message Router (NMR) in ServiceMix, which is intended for use by Camel applications deployed directly into the OSGi container. You can exchange objects with NMR and not only XML like this is the case with the JBI specification. The interest of this component is that you can interconnect camel routes deployed in different OSGI bundles. By contrast, the JBI component is intended for use by Camel applications deployed into the ServiceMix JBI container. InstallingThe NMR component is provided with Apache ServiceMix. It is not distributed with Camel. To install the NMR component in ServiceMix, enter the following command in the ServiceMix console window: features install nmr You also need to instantiate the NMR component. You can do this by editing your Spring configuration file, META-INF/spring/*.xml, and adding the following bean instance: <beans xmlns:osgi="http://www.springframework.org/schema/osgi" ... > ... <bean id="nmr" class="org.apache.servicemix.camel.nmr.ServiceMixComponent"> <property name="nmr"> <osgi:reference interface="org.apache.servicemix.nmr.api.NMR" /> </property> </bean> ... </beans> NMR consumer and producer endpointsThe following code:
from("nmr:MyServiceEndpoint")
Automatically exposes a new endpoint to the bus with endpoint name MyServiceEndpoint (see URI-format). When an NMR endpoint appears at the end of a route, for example:
to("nmr:MyServiceEndpoint")
The messages sent by this producer endpoint are sent to the already deployed JBI endpoint. URI formatnmr:endpointName URI Options
ExamplesConsumer from("nmr:MyServiceEndpoint") // consume nmr exchanges asynchronously from("nmr:MyServiceEndpoint?synchronous=true").to() // consume nmr exchanges synchronously and use the same thread as defined by NMR ThreadPool Producer from()...to("nmr:MyServiceEndpoint") // produce nmr exchanges asynchronously from()...to("nmr:MyServiceEndpoint?timeout=10000") // produce nmr exchanges synchronously and wait till 10s to receive response Using Stream bodiesIf you are using a stream type as the message body, you should be aware that a stream is only capable of being read once. So if you enable DEBUG logging, the body is usually logged and thus read. To deal with this, Camel has a streamCaching option that can cache the stream, enabling you to read it multiple times. from("nmr:MyEndpoint").streamCaching().to("xslt:transform.xsl", "bean:doSomething"); From Camel 1.5 onwards, the stream caching is default enabled, so it is not necessary to set the streamCaching() option. TestingNMR camel routes can be tested using the camel unit test approach even if they will be deployed next in different bundles on an OSGI runtime. With this aim in view, you will extend the ServiceMixNMR Mock class org.apache.servicemix.camel.nmr.AbstractComponentTest which will create a NMR bus, register the Camel NMR Component and the endpoints defined into the Camel routes. public class ExchangeUsingNMRTest extends AbstractComponentTest { @Test public void testProcessing() throws InterruptedException { MockEndpoint mock = getMockEndpoint("mock:simple"); mock.expectedBodiesReceived("Simple message body"); template.sendBody("direct:simple", "Simple message body"); assertMockEndpointsSatisfied(); } @Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { from("direct:simple").to("nmr:simple"); from("nmr:simple?synchronous=true").to("mock:simple"); } }; } } See AlsoQuartz ComponentThe quartz: component provides a scheduled delivery of messages using the Quartz scheduler. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-quartz</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
URI formatquartz://timerName?options quartz://groupName/timerName?options quartz://groupName/timerName/cronExpression (@deprecated) quartz://groupName/timerName/?cron=expression (Camel 2.0) quartz://timerName?cron=expression (Camel 2.0) The component uses either a CronTrigger or a SimpleTrigger. If no cron expression is provided, the component uses a simple trigger. If no groupName is provided, the quartz component uses the Camel group name. You can append query options to the URI in the following format, ?option=value&option=value&... Options
For example, the following routing rule will fire two timer events to the mock:results endpoint: from("quartz://myGroup/myTimerName?trigger.repeatInterval=2&trigger.repeatCount=1").routeId("myRoute").to("mock:result"); When using a StatefulJob, the JobDataMap is re-persisted after every execution of the job, thus preserving state for the next execution. Configuring quartz.properties fileBy default Quartz will look for a quartz.properties file in the root of the classpath. If you are using WAR deployments this means just drop the quartz.properties in WEB-INF/classes. However the Camel Quartz component also allows you to configure properties:
To do this you can configure this in Spring XML as follows <bean id="quartz" class="org.apache.camel.component.quartz.QuartzComponent"> <property name="propertiesFile" value="com/mycompany/myquartz.properties"/> </bean> Starting the Quartz schedulerAvailable as of Camel 2.4 The Quartz component offers an option to let the Quartz scheduler be started delayed, or not auto started at all.
To do this you can configure this in Spring XML as follows <bean id="quartz" class="org.apache.camel.component.quartz.QuartzComponent"> <property name="startDelayedSeconds" value="5"/> </bean> ClusteringAvailable as of Camel 2.4 If you use Quartz in clustered mode, e.g. the JobStore is clustered. Then from Camel 2.4 onwards the Quartz component will not pause/remove triggers when a node is being stopped/shutdown. This allows the trigger to keep running on the other nodes in the cluster. Note: When running in clustered node no checking is done to ensure unique job name/group for endpoints. Message HeadersCamel adds the getters from the Quartz Execution Context as header values. The following headers are added: The fireTime header contains the java.util.Date of when the exchange was fired. Using Cron TriggersAvailable as of Camel 2.0 For example, the following will fire a message every five minutes starting at 12pm (noon) to 6pm on weekdays:
from("quartz://myGroup/myTimerName?cron=0+0/5+12-18+?+*+MON-FRI").to("activemq:Totally.Rocks");
which is equivalent to using the cron expression 0 0/5 12-18 ? * MON-FRI The following table shows the URI character encodings we use to preserve valid URI syntax:
Using Cron Triggers in Camel 1.x@deprecated For example, the following endpoint URI will fire a message at 12pm (noon) every day
from("quartz://myGroup/myTimerName/0/0/12/*/*/$").to("activemq:Totally.Rocks");
which is equivalent to using the cron expression 0 0 12 * * ? The following table shows the URI character encodings we use to preserve valid URI syntax:
Specifying time zoneAvailable as of Camel 2.8.1
quartz://groupName/timerName?cron=0+0/5+12-18+?+*+MON-FRI&trigger.timeZone=Europe/Stockholm
The timeZone value is the values accepted by java.util.TimeZone. In Camel 2.8.0 or older versions you would have to provide your custom String to java.util.TimeZone Type Converter to be able configure this from the endpoint uri. See AlsoQuickFIX/J ComponentAvailable as of Camel 2.0 The quickfix component adapts the QuickFIX/J FIX engine for using in Camel . This component uses the standard Financial Interchange (FIX) protocol for message transport.
Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-quickfix</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatquickfix:configFile[?sessionID=sessionID] The configFile is the name of the QuickFIX/J configuration to use for the FIX engine (located as a resource found in your classpath). The optional sessionID identifies a specific FIX session. The format of the sessionID is: (BeginString):(SenderCompID)[/(SenderSubID)[/(SenderLocationID)]]->(TargetCompID)[/(TargetSubID)[/(TargetLocationID)]] Example URIs: quickfix:config.cfg quickfix:config.cfg?sessionID=FIX.4.2:MyTradingCompany->SomeExchange EndpointsFIX sessions are endpoints for the quickfix component. An endpoint URI may specify a single session or all sessions managed by a specific QuickFIX/J engine. Typical applications will use only one FIX engine but advanced users may create multiple FIX engines by referencing different configuration files in quickfix component endpoint URIs. When a consumer does not include a session ID in the endpoint URI, it will receive exchanges for all sessions managed by the FIX engine associated with the configuration file specified in the URI. If a producer does not specify a session in the endpoint URI then it must include the session-related fields in the FIX message being sent. If a session is specified in the URI then the component will automatically inject the session-related fields into the FIX message. Exchange FormatThe exchange headers include information to help with exchange filtering, routing and other processing. The following headers are available:
The DataDictionary header is useful if string messages are being received and need to be parsed in a route. QuickFIX/J requires a data dictionary to parse certain types of messages (with repeating groups, for example). By injecting a DataDictionary header in the route after receiving a message string, the FIX engine can properly parse the data. QuickFIX/J Configuration ExtensionsWhen using QuickFIX/J directly, one typically writes code to create instances of logging adapters, message stores and communication connectors. The quickfix component will automatically create instances of these classes based on information in the configuration file. It also provides defaults for many of the common required settings and adds additional capabilities (like the ability to activate JMX support). The following sections describe how the quickfix component processes the QuickFIX/J configuration. For comprehensive information about QuickFIX/J configuration, see the QFJ user manual. Communication ConnectorsWhen the component detects an initiator or acceptor session setting in the QuickFIX/J configuration file it will automatically create the corresponding initiator and/or acceptor connector. These settings can be in the default or in a specific session section of the configuration file.
The threading model for the QuickFIX/J session connectors can also be specified. These settings affect all sessions in the configuration file and must be placed in the settings default section.
LoggingThe QuickFIX/J logger implementation can be specified by including the following settings in the default section of the configuration file. The ScreenLog is the default if none of the following settings are present in the configuration. It's an error to include settings that imply more than one log implementation. The log factory implementation can also be set directly on the Quickfix component. This will override any related values in the QuickFIX/J settings file.
Message StoreThe QuickFIX/J message store implementation can be specified by including the following settings in the default section of the configuration file. The MemoryStore is the default if none of the following settings are present in the configuration. It's an error to include settings that imply more than one message store implementation. The message store factory implementation can also be set directly on the Quickfix component. This will override any related values in the QuickFIX/J settings file.
Message FactoryA message factory is used to construct domain objects from raw FIX messages. The default message factory is DefaultMessageFactory. However, advanced applications may require a custom message factory. This can be set on the QuickFIX/J component. JMX
Other DefaultsThe component provides some default settings for what are normally required settings in QuickFIX/J configuration files. SessionStartTime and SessionEndTime default to "00:00:00", meaning the session will not be automatically started and stopped. The HeartBtInt (heartbeat interval) defaults to 30 seconds. Minimal Initiator Configuration Example[SESSION] ConnectionType=initiator BeginString=FIX.4.4 SenderCompID=YOUR_SENDER TargetCompID=YOUR_TARGET Using the InOut Message Exchange PatternCamel 2.8+ Although the FIX protocol is event-driven and asynchronous, there are specific pairs of messages Implementing InOut Exchanges for ConsumersAdd "exchangePattern=InOut" to the QuickFIX/J enpoint URI. The MessageOrderStatusService in
from("quickfix:examples/inprocess.cfg?sessionID=FIX.4.2:MARKET->TRADER&exchangePattern=InOut")
.filter(header(QuickfixjEndpoint.MESSAGE_TYPE_KEY).isEqualTo(MsgType.ORDER_STATUS_REQUEST))
.bean(new MarketOrderStatusService());
Implementing InOut Exchanges for ProducersFor producers, sending a message will block until a reply is received or a timeout occurs. There
The correlation criteria is defined with a MessagePredicate object. The following example will treat
exchange.setProperty(QuickfixjProducer.CORRELATION_CRITERIA_KEY,
new MessagePredicate(new SessionID(sessionID), MsgType.EXECUTION_REPORT)
.withField(ExecTransType.FIELD, Integer.toString(ExecTransType.STATUS))
.withField(OrderID.FIELD, request.getString(OrderID.FIELD)));
ExampleThe source code contains an example called RequestReplyExample that demonstrates the InOut exchanges The Spring configuration have changed from Camel 2.9 onwards. See further below for example. Spring ConfigurationCamel 2.6 - 2.8.x The QuickFIX/J component includes a Spring FactoryBean for configuring the session settings within a Spring context. A type converter for QuickFIX/J session ID strings is also included. The following example shows a simple configuration of an acceptor and initiator session with default settings for both sessions. <!-- camel route --> <camelContext id="quickfixjContext" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="quickfix:example"/> <filter> <simple>${in.header.EventCategory} == 'AppMessageReceived'</simple> <to uri="log:test"/> </filter> </route> </camelContext> <!-- quickfix component --> <bean id="quickfix" class="org.apache.camel.component.quickfixj.QuickfixjComponent"> <property name="engineSettings"> <util:map> <entry key="quickfix:example" value-ref="quickfixjSettings"/> </util:map> </property> <property name="messageFactory"> <bean class="org.apache.camel.component.quickfixj.QuickfixjSpringTest.CustomMessageFactory"/> </property> </bean> <!-- quickfix settings --> <bean id="quickfixjSettings" class="org.apache.camel.component.quickfixj.QuickfixjSettingsFactory"> <property name="defaultSettings"> <util:map> <entry key="SocketConnectProtocol" value="VM_PIPE"/> <entry key="SocketAcceptProtocol" value="VM_PIPE"/> <entry key="UseDataDictionary" value="N"/> </util:map> </property> <property name="sessionSettings"> <util:map> <entry key="FIX.4.2:INITIATOR->ACCEPTOR"> <util:map> <entry key="ConnectionType" value="initiator"/> <entry key="SocketConnectHost" value="localhost"/> <entry key="SocketConnectPort" value="5000"/> </util:map> </entry> <entry key="FIX.4.2:ACCEPTOR->INITIATOR"> <util:map> <entry key="ConnectionType" value="acceptor"/> <entry key="SocketAcceptPort" value="5000"/> </util:map> </entry> </util:map> </property> </bean> Camel 2.9 onwards The QuickFIX/J component includes a QuickfixjConfiguration class for configuring the session settings. A type converter for QuickFIX/J session ID strings is also included. The following example shows a simple configuration of an acceptor and initiator session with default settings for both sessions. <!-- camel route --> <camelContext id="quickfixjContext" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="quickfix:example"/> <filter> <simple>${in.header.EventCategory} == 'AppMessageReceived'</simple> <to uri="log:test"/> </filter> </route> </camelContext> <!-- quickfix component --> <bean id="quickfix" class="org.apache.camel.component.quickfixj.QuickfixjComponent"> <property name="configurations"> <util:map> <entry key="example" value-ref="quickfixjConfiguration"/> </util:map> </property> <property name="messageFactory"> <bean class="org.apache.camel.component.quickfixj.QuickfixjSpringTest.CustomMessageFactory"/> </property> </bean> <!-- quickfix settings --> <bean id="quickfixjConfiguration" class="org.apache.camel.component.quickfixj.QuickfixjConfiguration"> <property name="defaultSettings"> <util:map> <entry key="SocketConnectProtocol" value="VM_PIPE"/> <entry key="SocketAcceptProtocol" value="VM_PIPE"/> <entry key="UseDataDictionary" value="N"/> </util:map> </property> <property name="sessionSettings"> <util:map> <entry key="FIX.4.2:INITIATOR->ACCEPTOR"> <util:map> <entry key="ConnectionType" value="initiator"/> <entry key="SocketConnectHost" value="localhost"/> <entry key="SocketConnectPort" value="5000"/> </util:map> </entry> <entry key="FIX.4.2:ACCEPTOR->INITIATOR"> <util:map> <entry key="ConnectionType" value="acceptor"/> <entry key="SocketAcceptPort" value="5000"/> </util:map> </entry> </util:map> </property> </bean> Exception handlingQuickFIX/J behavior can be modified if certain exceptions are thrown during processing of a message. If a RejectLogon exception is thrown while processing an incoming logon administrative message, then the logon will be rejected. Normally, QuickFIX/J handles the logon process automatically. However, sometimes an outgoing logon message must be modified to include credentials required by a FIX counterparty. If the FIX logon message body is modified when sending a logon message (EventCategory=AdminMessageSent the modified message will be sent to the counterparty. It is important that the outgoing logon message is being processed synchronously. If it is processed asynchronously (on another thread), the FIX engine will immediately send the unmodified outgoing message when it's callback method returns. FIX Sequence Number ManagementIf an application exception is thrown during synchronous exchange processing, this will cause QuickFIX/J to not increment incoming FIX message sequence numbers and will cause a resend of the counterparty message. This FIX protocol behavior is primarily intended to handle transport errors rather than application errors. There are risks associated with using this mechanism to handle application errors. The primary risk is that the message will repeatedly cause application errors each time it's re-received. A better solution is to persist the incoming message (database, JMS queue) immediately before processing it. This also allows the application to process messages asynchronously without losing messages when errors occur. Although it's possible to send messages to a FIX session before it's logged on (the messages will be sent at logon time), it is usually a better practice to wait until the session is logged on. This eliminates the required sequence number resynchronization steps at logon. Waiting for session logon can be done by setting up a route that processes the SessionLogon event category and signals the application to start sending messages. See the FIX protocol specifications and the QuickFIX/J documentation for more details about FIX sequence number management. Route ExamplesSeveral examples are included in the QuickFIX/J component source code (test subdirectories). One of these examples implements a trival trade excecution simulation. The example defines an application component that uses the URI scheme "trade-executor". The following route receives messages for the trade executor session and passes application messages to the trade executor component. from("quickfix:examples/inprocess.cfg?sessionID=FIX.4.2:MARKET->TRADER"). filter(header(QuickfixjEndpoint.EVENT_CATEGORY_KEY).isEqualTo(QuickfixjEventCategory.AppMessageReceived)). to("trade-executor:market"); The trade executor component generates messages that are routed back to the trade session. The session ID must be set in the FIX message itself since no session ID is specified in the endpoint URI. from("trade-executor:market").to("quickfix:examples/inprocess.cfg"); The trader session consumes execution report messages from the market and processes them. from("quickfix:examples/inprocess.cfg?sessionID=FIX.4.2:TRADER->MARKET"). filter(header(QuickfixjEndpoint.MESSAGE_TYPE_KEY).isEqualTo(MsgType.EXECUTION_REPORT)). bean(new MyTradeExecutionProcessor()); QuickFIX/J Component Prior to Camel 2.5Available since Camel 2.0 The quickfix component is an implementation of the QuickFIX/J engine for Java . This engine allows to connect to a FIX server which is used to exchange financial messages according to FIX protocol standard. Note: The component can be used to send/receives messages to a FIX server. URI formatquickfix-server:config file quickfix-client:config file Where config file is the location (in your classpath) of the quickfix configuration file used to configure the engine at the startup. Note: Information about parameters available for quickfix can be found on QuickFIX/J web site. The quickfix-server endpoint must be used to receive from FIX server FIX messages and quickfix-client endpoint in the case that you want to send messages to a FIX gateway. Exchange data formatThe QuickFIX/J engine is like CXF component a messaging bus using MINA as protocol layer to create the socket connection with the FIX engine gateway. When QuickFIX/J engine receives a message, then it create a QuickFix.Message instance which is next received by the camel endpoint. This object is a 'mapping object' created from a FIX message formatted initially as a collection of key value pairs data. You can use this object or you can use the method 'toString' to retrieve the original FIX message. Note: Alternatively, you can use camel bindy dataformat to transform the FIX message into your own java POJO When a message must be send to QuickFix, then you must create a QuickFix.Message instance. SamplesDirection : to FIX gateway <route> <from uri="activemq:queue:fix"/> <bean ref="fixService" method="createFixMessage"/> // bean method in charge to transform message into a QuickFix.Message <to uri="quickfix-client:META-INF/quickfix/client.cfg"/> // Quickfix engine who will send the FIX messages to the gateway </route> Direction : from FIX gateway <route> <from uri="quickfix-server:META-INF/quickfix/server.cfg"/> // QuickFix engine who will receive the message from FIX gateway <bean ref="fixService" method="parseFixMessage"/> // bean method parsing the QuickFix.Message <to uri="uri="activemq:queue:fix"/>" </route> See AlsoPrinter ComponentAvailable as of Camel 2.1 The printer component provides a way to direct payloads on a route to a printer. Obviously the payload has to be a formatted piece of payload in order for the component to appropriately print it. The objective is to be able to direct specific payloads as jobs to a line printer in a camel flow. This component only supports a camel producer endpoint. The functionality allows for the payload to be printed on a default printer, named local, remote or wirelessly linked printer using the javax printing API under the covers. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-printer</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatSince the URI scheme for a printer has not been standardized (the nearest thing to a standard being the IETF print standard) and therefore not uniformly applied by vendors, we have chosen "lpr" as the scheme. lpr://localhost/default[?options] lpr://remotehost:port/path/to/printer[?options] You can append query options to the URI in the following format, ?option=value&option=value&... Options
Sending Messages to a PrinterPrinter ProducerSending data to the printer is very straightforward and involves creating a producer endpoint that can be sent message exchanges on in route. Usage SamplesExample 1: Printing text based payloads on a Default printer using letter stationary and one-sided modeRouteBuilder builder = new RouteBuilder() { public void configure() { from(file://inputdir/?delete=true) .to("lpr://localhost/default?copies=2" + "&flavor=DocFlavor.INPUT_STREAM&" + "&mimeType=AUTOSENSE" + "&mediaSize=na-letter" + "&sides=one-sided") }}; Example 2: Printing GIF based payloads on a Remote printer using A4 stationary and one-sided modeRouteBuilder builder = new RouteBuilder() { public void configure() { from(file://inputdir/?delete=true) .to("lpr://remotehost/sales/salesprinter" + "?copies=2&sides=one-sided" + "&mimeType=GIF&mediaSize=iso-a4" + "&flavor=DocFlavor.INPUT_STREAM") }}; Example 3: Printing JPEG based payloads on a Remote printer using Japanese Postcard stationary and one-sided modeRouteBuilder builder = new RouteBuilder() { public void configure() { from(file://inputdir/?delete=true) .to("lpr://remotehost/sales/salesprinter" + "?copies=2&sides=one-sided" + "&mimeType=JPEG" + "&mediaSize=japanese-postcard" + "&flavor=DocFlavor.INPUT_STREAM") }}; Properties ComponentAvailable as of Camel 2.3 URI formatproperties:key[?options] Where key is the key for the property to lookup Options
Using PropertyPlaceholderAvailable as of Camel 2.3 Camel now provides a new PropertiesComponent in camel-core which allows you to use property placeholders when defining Camel Endpoint URIs. The property placeholder is generally in use when doing:
SyntaxThe syntax to use Camel's property placeholder is to use {{key}} for example {{file.uri}} where file.uri is the property key. PropertyResolverCamel provides a pluggable mechanism which allows 3rd part to provide their own resolver to lookup properties. Camel provides a default implementation org.apache.camel.component.properties.DefaultPropertiesResolver which is capable of loading properties from the file system, classpath or Registry. You can prefix the locations with either:
Defining locationThe PropertiesResolver need to know a location(s) where to resolve the properties. You can define 1 to many locations. If you define the location in a single String property you can separate multiple locations with comma such as:
pc.setLocation("com/mycompany/myprop.properties,com/mycompany/other.properties");
Using system and environment variables in locationsAvailable as of Camel 2.7 The location now supports using placeholders for JVM system properties and OS environments variables. For example:
location=file:${karaf.home}/etc/foo.properties
In the location above we defined a location using the file scheme using the JVM system property with key karaf.home. To use an OS environment variable instead you would have to prefix with env:
location=file:${env:APP_HOME}/etc/foo.properties
Where APP_HOME is an OS environment. You can have multiple placeholders in the same location, such as:
location=file:${env:APP_HOME}/etc/${prop.name}.properties
Configuring in Java DSLYou have to create and register the PropertiesComponent under the name properties such as: PropertiesComponent pc = new PropertiesComponent(); pc.setLocation("classpath:com/mycompany/myprop.properties"); context.addComponent("properties", pc); Configuring in Spring XMLSpring XML offers two variations to configure. You can define a spring bean as a PropertiesComponent which resembles the way done in Java DSL. Or you can use the <propertyPlaceholder> tag. <bean id="properties" class="org.apache.camel.component.properties.PropertiesComponent"> <property name="location" value="classpath:com/mycompany/myprop.properties"/> </bean> Using the <propertyPlaceholder> tag makes the configuration a bit more fresh such as: <camelContext ...> <propertyPlaceholder id="properties" location="com/mycompany/myprop.properties"/> </camelContext> Using a Properties from the RegistryAvailable as of Camel 2.4 Then you could setup the Properties component as follows:
<propertyPlaceholder id="properties" location="ref:myProperties"/>
Where myProperties is the id to use for lookup in the OSGi registry. Notice we use the ref: prefix to tell Camel that it should lookup the properties for the Registry. Examples using properties componentWhen using property placeholders in the endpoint URIs you can either use the properties: component or define the placeholders directly in the URI. We will show example of both cases, starting with the former. // properties cool.end=mock:result // route from("direct:start").to("properties:{{cool.end}}"); You can also use placeholders as a part of the endpoint uri: // properties cool.foo=result // route from("direct:start").to("properties:mock:{{cool.foo}}"); In the example above the to endpoint will be resolved to mock:result. You can also have properties with refer to each other such as: // properties cool.foo=result cool.concat=mock:{{cool.foo}} // route from("direct:start").to("properties:mock:{{cool.concat}}"); Notice how cool.concat refer to another property. The properties: component also offers you to override and provide a location in the given uri using the locations option: from("direct:start").to("properties:bar.end?locations=com/mycompany/bar.properties"); ExamplesYou can also use property placeholders directly in the endpoint uris without having to use properties:. // properties cool.foo=result // route from("direct:start").to("mock:{{cool.foo}}"); And you can use them in multiple wherever you want them: // properties cool.start=direct:start cool.showid=true cool.result=result // route from("{{cool.start}}") .to("log:{{cool.start}}?showBodyType=false&showExchangeId={{cool.showid}}") .to("mock:{{cool.result}}"); You can also your property placeholders when using ProducerTemplate for example: template.sendBody("{{cool.start}}", "Hello World"); Example with Simple languageThe Simple language now also support using property placeholders, for example in the route below: // properties cheese.quote=Camel rocks // route from("direct:start") .transform().simple("Hi ${body} do you think ${properties:cheese.quote}?"); You can also specify the location in the Simple language for example: // bar.properties bar.quote=Beer tastes good // route from("direct:start") .transform().simple("Hi ${body}. ${properties:com/mycompany/bar.properties:bar.quote}."); Additional property placeholder supported in Spring XMLThe property placeholders is also supported in many of the Camel Spring XML tags such as <package>, <packageScan>, <contextScan>, <jmxAgent>, <endpoint>, <routeBuilder>, <proxy> and the others. The example below has property placeholder in the <jmxAgent> tag: <camelContext xmlns="http://camel.apache.org/schema/spring"> <propertyPlaceholder id="properties" location="org/apache/camel/spring/jmx.properties"/> <!-- we can use propery placeholders when we define the JMX agent --> <jmxAgent id="agent" registryPort="{{myjmx.port}}" disabled="{{myjmx.disabled}}" usePlatformMBeanServer="{{myjmx.usePlatform}}" createConnector="true" statisticsLevel="RoutesOnly"/> <route id="foo" autoStartup="false"> <from uri="seda:start"/> <to uri="mock:result"/> </route> </camelContext> You can also define property placeholders in the various attributes on the <camelContext> tag such as trace as shown here: <camelContext trace="{{foo.trace}}" xmlns="http://camel.apache.org/schema/spring"> <propertyPlaceholder id="properties" location="org/apache/camel/spring/processor/myprop.properties"/> <template id="camelTemplate" defaultEndpoint="{{foo.cool}}"/> <route> <from uri="direct:start"/> <setHeader headerName="{{foo.header}}"> <simple>${in.body} World!</simple> </setHeader> <to uri="mock:result"/> </route> </camelContext> Overriding a property setting using a JVM System PropertyAvailable as of Camel 2.5 PropertiesComponent pc = context.getComponent("properties", PropertiesComponent.class); pc.setCache(false); System.setProperty("cool.end", "mock:override"); System.setProperty("cool.result", "override"); context.addRoutes(new RouteBuilder() { @Override public void configure() throws Exception { from("direct:start").to("properties:cool.end"); from("direct:foo").to("properties:mock:{{cool.result}}"); } }); context.start(); getMockEndpoint("mock:override").expectedMessageCount(2); template.sendBody("direct:start", "Hello World"); template.sendBody("direct:foo", "Hello Foo"); System.clearProperty("cool.end"); System.clearProperty("cool.result"); assertMockEndpointsSatisfied(); Using property placeholders for any kind of attribute in the XML DSLAvailable as of Camel 2.7 Previously it was only the xs:string type attributes in the XML DSL that support placeholders. For example often a timeout attribute would be a xs:int type and thus you cannot set a string value as the placeholder key. This is now possible from Camel 2.7 onwards using a special placeholder namespace. In the example below we use the prop prefix for the namespace http://camel.apache.org/schema/placeholder by which we can use the prop prefix in the attributes in the XML DSLs. Notice how we use that in the Multicast to indicate that the option stopOnException should be the value of the placeholder with the key "stop". <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:prop="http://camel.apache.org/schema/placeholder" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd "> <!-- Notice in the declaration above, we have defined the prop prefix as the Camel placeholder namespace --> <bean id="damn" class="java.lang.IllegalArgumentException"> <constructor-arg index="0" value="Damn"/> </bean> <camelContext xmlns="http://camel.apache.org/schema/spring"> <propertyPlaceholder id="properties" location="classpath:org/apache/camel/component/properties/myprop.properties" xmlns="http://camel.apache.org/schema/spring"/> <route> <from uri="direct:start"/> <!-- use prop namespace, to define a property placeholder, which maps to option stopOnException={{stop}} --> <multicast prop:stopOnException="stop"> <to uri="mock:a"/> <throwException ref="damn"/> <to uri="mock:b"/> </multicast> </route> </camelContext> </beans> In our properties file we have the value defined as
stop=true
Using property placeholder in the Java DSLAvailable as of Camel 2.7 Likewise we have added support for defining placeholders in the Java DSL using the new placeholder DSL as shown in the following equivalent example: from("direct:start") // use a property placeholder for the option stopOnException on the Multicast EIP // which should have the value of {{stop}} key being looked up in the properties file .multicast().placeholder("stopOnException", "stop") .to("mock:a").throwException(new IllegalAccessException("Damn")).to("mock:b"); Using Blueprint property placeholder with Camel routesAvailable as of Camel 2.7 Camel supports Blueprint which also offers a property placeholder service. Camel supports convention over configuration, so all you have to do is to define the OSGi Blueprint property placeholder in the XML file as shown below: Using OSGi blueprint property placeholders in Camel routes <blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0" xsi:schemaLocation=" http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd"> <!-- OSGI blueprint property placeholder --> <cm:property-placeholder id="myblueprint.placeholder" persistent-id="camel.blueprint"> <!-- list some properties for this test --> <cm:default-properties> <cm:property name="result" value="mock:result"/> </cm:default-properties> </cm:property-placeholder> <camelContext xmlns="http://camel.apache.org/schema/blueprint"> <!-- in the route we can use {{ }} placeholders which will lookup in blueprint as Camel will auto detect the OSGi blueprint property placeholder and use it --> <route> <from uri="direct:start"/> <to uri="mock:foo"/> <to uri="{{result}}"/> </route> </camelContext> </blueprint> By default Camel detects and uses OSGi blueprint property placeholder service. You can disable this by setting the attribute useBlueprintPropertyResolver to false on the <camelContext> definition.
You can also explicit refer to a specific OSGi blueprint property placeholder by its id. For that you need to use the Camel's <propertyPlaceholder> as shown in the example below: Explicit referring to a OSGi blueprint placeholder in Camel <blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0" xsi:schemaLocation=" http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd"> <!-- OSGI blueprint property placeholder --> <cm:property-placeholder id="myblueprint.placeholder" persistent-id="camel.blueprint"> <!-- list some properties for this test --> <cm:default-properties> <cm:property name="prefix.result" value="mock:result"/> </cm:default-properties> </cm:property-placeholder> <camelContext xmlns="http://camel.apache.org/schema/blueprint"> <!-- using Camel properties component and refer to the blueprint property placeholder by its id --> <propertyPlaceholder id="properties" location="blueprint:myblueprint.placeholder" prefixToken="[[" suffixToken="]]" propertyPrefix="prefix."/> <!-- in the route we can use {{ }} placeholders which will lookup in blueprint --> <route> <from uri="direct:start"/> <to uri="mock:foo"/> <to uri="[[result]]"/> </route> </camelContext> </blueprint> Notice how we use the blueprint scheme to refer to the OSGi blueprint placeholder by its id. This allows you to mix and match, for example you can also have additional schemes in the location. For example to load a file from the classpath you can do:
location="blueprint:myblueprint.placeholder,classpath:myproperties.properties"
Each location is separated by comma. See Also
Ref ComponentThe ref: component is used for lookup of existing endpoints bound in the Registry. URI formatref:someName Where someName is the name of an endpoint in the Registry (usually, but not always, the Spring registry). If you are using the Spring registry, someName would be the bean ID of an endpoint in the Spring registry. Runtime lookupThis component can be used when you need dynamic discovery of endpoints in the Registry where you can compute the URI at runtime. Then you can look up the endpoint using the following code: // lookup the endpoint String myEndpointRef = "bigspenderOrder"; Endpoint endpoint = context.getEndpoint("ref:" + myEndpointRef); Producer producer = endpoint.createProducer(); Exchange exchange = producer.createExchange(); exchange.getIn().setBody(payloadToSend); // send the exchange producer.process(exchange); ... And you could have a list of endpoints defined in the Registry such as: <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring"> <endpoint id="normalOrder" uri="activemq:order.slow"/> <endpoint id="bigspenderOrder" uri="activemq:order.high"/> ... </camelContext> SampleIn the sample below we use the ref: in the URI to reference the endpoint with the spring ID, endpoint2: <bean id="mybean" class="org.apache.camel.spring.example.DummyBean"> <property name="endpoint" ref="endpoint1"/> </bean> <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <jmxAgent id="agent" disabled="true"/> <endpoint id="endpoint1" uri="direct:start"/> <endpoint id="endpoint2" uri="mock:end"/> <route> <from ref="endpoint1"/> <to uri="ref:endpoint2"/> </route> </camelContext> You could, of course, have used the ref attribute instead:
<to ref="endpoint2"/>
Which is the more common way to write it. See AlsoRestlet ComponentThe Restlet component provides Restlet based endpoints for consuming and producing RESTful resources. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-restlet</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatrestlet:restletUrl[?options] Format of restletUrl:
protocol://hostname[:port][/resourcePattern]
Restlet promotes decoupling of protocol and application concerns. The reference implementation of Restlet Engine supports a number of protocols. However, we have tested the HTTP protocol only. The default port is port 80. We do not automatically switch default port based on the protocol yet. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Message HeadersCamel 1.x
Camel 2.x
Message BodyCamel will store the restlet response from the external server on the OUT body. All headers from the IN message will be copied to the OUT message, so that headers are preserved during routing. SamplesRestlet Endpoint with AuthenticationThe following route starts a restlet consumer endpoint that listens for POST requests on http://localhost:8080. The processor creates a response that echoes the request body and the value of the id header. from("restlet:http://localhost:" + port + "/securedOrders?restletMethod=post&restletRealm=#realm").process(new Processor() { public void process(Exchange exchange) throws Exception { exchange.getOut().setBody( "received [" + exchange.getIn().getBody() + "] as an order id = " + exchange.getIn().getHeader("id")); } }); The restletRealm setting (in 2.x, use the # notation, that is, restletRealm=#refName)in the URI query is used to look up a Realm Map in the registry. If this option is specified, the restlet consumer uses the information to authenticate user logins. Only authenticated requests can access the resources. In this sample, we create a Spring application context that serves as a registry. The bean ID of the Realm Map should match the restletRealmRef. <util:map id="realm"> <entry key="admin" value="foo" /> <entry key="bar" value="foo" /> </util:map> The following sample starts a direct endpoint that sends requests to the server on http://localhost:8080 (that is, our restlet consumer endpoint). // Note: restletMethod and restletRealmRef are stripped // from the query before a request is sent as they are // only processed by Camel. from("direct:start-auth").to("restlet:http://localhost:" + port + "/securedOrders?restletMethod=post"); That is all we need. We are ready to send a request and try out the restlet component: final String id = "89531"; Map<String, Object> headers = new HashMap<String, Object>(); headers.put(RestletConstants.RESTLET_LOGIN, "admin"); headers.put(RestletConstants.RESTLET_PASSWORD, "foo"); headers.put("id", id); String response = (String)template.requestBodyAndHeaders( "direct:start-auth", "<order foo='1'/>", headers); The sample client sends a request to the direct:start-auth endpoint with the following headers:
The sample client gets a response like the following: received [<order foo='1'/>] as an order id = 89531 Single restlet endpoint to service multiple methods and URI templates (2.0 or later)It is possible to create a single route to service multiple HTTP methods using the restletMethods option. This snippet also shows how to retrieve the request method from the header: from("restlet:http://localhost:" + portNum + "/users/{username}?restletMethods=post,get") .process(new Processor() { public void process(Exchange exchange) throws Exception { // echo the method exchange.getOut().setBody(exchange.getIn().getHeader(Exchange.HTTP_METHOD, String.class)); } }); In addition to servicing multiple methods, the next snippet shows how to create an endpoint that supports multiple URI templates using the restletUriPatterns option. The request URI is available in the header of the IN message as well. If a URI pattern has been defined in the endpoint URI (which is not the case in this sample), both the URI pattern defined in the endpoint and the restletUriPatterns option will be honored. from("restlet:http://localhost:" + portNum + "?restletMethods=post,get&restletUriPatterns=#uriTemplates") .process(new Processor() { public void process(Exchange exchange) throws Exception { // echo the method String uri = exchange.getIn().getHeader(Exchange.HTTP_URI, String.class); String out = exchange.getIn().getHeader(Exchange.HTTP_METHOD, String.class); if (("http://localhost:" + portNum + "/users/homer").equals(uri)) { exchange.getOut().setBody(out + " " + exchange.getIn().getHeader("username", String.class)); } else if (("http://localhost:" + portNum + "/atom/collection/foo/component/bar").equals(uri)) { exchange.getOut().setBody(out + " " + exchange.getIn().getHeader("id", String.class) + " " + exchange.getIn().getHeader("cid", String.class)); } } }); The restletUriPatterns=#uriTemplates option references the List<String> bean defined in the Spring XML configuration. <util:list id="uriTemplates"> <value>/users/{username}</value> <value>/atom/collection/{id}/component/{cid}</value> </util:list> Using Restlet API to populate responseAvailable as of Camel 2.8 You may want to use the org.restlet.Response API to populate the response. This gives you full access to the Restlet API and fine grained control of the response. See the route snippet below where we generate the response from an inlined Camel Processor: Generating response using Restlet Response API from("restlet:http://localhost:" + portNum + "/users/{id}/like/{beer}") .process(new Processor() { public void process(Exchange exchange) throws Exception { // the Restlet request should be available if neeeded Request request = exchange.getIn().getHeader(RestletConstants.RESTLET_REQUEST, Request.class); assertNotNull("Restlet Request", request); // use Restlet API to create the response Response response = exchange.getIn().getHeader(RestletConstants.RESTLET_RESPONSE, Response.class); assertNotNull("Restlet Response", response); response.setStatus(Status.SUCCESS_OK); response.setEntity("<response>Beer is Good</response>", MediaType.TEXT_XML); exchange.getOut().setBody(response); } }); Using the Restlet servlet within a webappAvailable as of Camel 2.8 Use of the Restlet servlet within a servlet container enables routes to be configured with relative paths in URIs (removing the restrictions of hard-coded absolute URIs) and for the hosting servlet container to handle incoming requests (rather than have to spawn a separate server process on a new port). To configure, add the following to your camel-context.xml; <camelContext> <route id="RS_RestletDemo"> <from uri="restlet:/demo/{id}" /> <transform> <simple>Request type : ${header.CamelHttpMethod} and ID : ${header.id}</simple> </transform> </route> </camelContext> <bean id="RestletComponent" class="org.restlet.Component" /> <bean id="RestletComponentService" class="org.apache.camel.component.restlet.RestletComponent"> <constructor-arg index="0"> <ref bean="RestletComponent" /> </constructor-arg> </bean> And add this to your web.xml; <!-- Restlet Servlet --> <servlet> <servlet-name>RestletServlet</servlet-name> <servlet-class>org.restlet.ext.spring.SpringServerServlet</servlet-class> <init-param> <param-name>org.restlet.component</param-name> <param-value>RestletComponent</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>RestletServlet</servlet-name> <url-pattern>/rs/*</url-pattern> </servlet-mapping> You will then be able to access the deployed route at http://localhost:8080/mywebapp/rs/demo/1234 where; localhost:8080 is the server and port of your servlet container
"Request type : GET and ID : 1234"
You will need to add dependency on the Spring extension to restlet which you can do in your Maven pom.xml file: <dependency> <groupId>org.restlet.jee</groupId> <artifactId>org.restlet.ext.spring</artifactId> <version>${restlet-version}</version> </dependency> And you would need to add dependency on the restlet maven repository as well: <repository> <id>maven-restlet</id> <name>Public online Restlet repository</name> <url>http://maven.restlet.org</url> </repository> See AlsoRMI ComponentThe rmi: component binds PojoExchanges to the RMI protocol (JRMP). Since this binding is just using RMI, normal RMI rules still apply regarding what methods can be invoked. This component supports only PojoExchanges that carry a method invocation from an interface that extends the Remote interface. All parameters in the method should be either Serializable or Remote objects. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-rmi</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
rmi://rmi-regisitry-host:rmi-registry-port/registry-path[?options]
For example:
rmi://localhost:1099/path/to/service
You can append query options to the URI in the following format, ?option=value&option=value&... Options
UsingTo call out to an existing RMI service registered in an RMI registry, create a route similar to the following: from("pojo:foo").to("rmi://localhost:1099/foo"); To bind an existing camel processor or service in an RMI registry, define an RMI endpoint as follows: RmiEndpoint endpoint= (RmiEndpoint) endpoint("rmi://localhost:1099/bar"); endpoint.setRemoteInterfaces(ISay.class); from(endpoint).to("pojo:bar"); Note that when binding an RMI consumer endpoint, you must specify the Remote interfaces exposed. In XML DSL you can do as follows from Camel 2.7 onwards:
<camel:route>
<from uri="rmi://localhost:37541/helloServiceBean?remoteInterfaces=org.apache.camel.example.osgi.HelloService"/>
<to uri="bean:helloServiceBean"/>
</camel:route>
See AlsoRSS ComponentAvailable as of Camel 2.0 The rss: component is used for polling RSS feeds. Camel will default poll the feed every 60th seconds. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-rss</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> Note: The component currently only supports polling (consuming) feeds.
URI formatrss:rssUri Where rssUri is the URI to the RSS feed to poll. You can append query options to the URI in the following format, ?option=value&option=value&... Options
Exchange data typesCamel initializes the In body on the Exchange with a ROME SyndFeed. Depending on the value of the splitEntries flag, Camel returns either a SyndFeed with one SyndEntry or a java.util.List of SyndEntrys.
Message Headers
RSS DataformatThe RSS component ships with an RSS dataformat that can be used to convert between String (as XML) and ROME RSS model objects.
A route using this would look something like this: from("rss:file:src/test/data/rss20.xml?splitEntries=false&consumer.delay=1000").marshal().rss().to("mock:marshal"); The purpose of this feature is to make it possible to use Camel's lovely built-in expressions for manipulating RSS messages. As shown below, an XPath expression can be used to filter the RSS message: // only entries with Camel in the title will get through the filter from("rss:file:src/test/data/rss20.xml?splitEntries=true&consumer.delay=100") .marshal().rss().filter().xpath("//item/title[contains(.,'Camel')]").to("mock:result"); Filtering entriesYou can filter out entries quite easily using XPath, as shown in the data format section above. You can also exploit Camel's Bean Integration to implement your own conditions. For instance, a filter equivalent to the XPath example above would be: // only entries with Camel in the title will get through the filter from("rss:file:src/test/data/rss20.xml?splitEntries=true&consumer.delay=100"). filter().method("myFilterBean", "titleContainsCamel").to("mock:result"); The custom bean for this would be: public static class FilterBean { public boolean titleContainsCamel(@Body SyndFeed feed) { SyndEntry firstEntry = (SyndEntry) feed.getEntries().get(0); return firstEntry.getTitle().contains("Camel"); } } See AlsoUnable to render {include} Couldn't find a page to include called: Scalate
SEDA ComponentThe seda: component provides asynchronous SEDA behavior, so that messages are exchanged on a BlockingQueue and consumers are invoked in a separate thread from the producer. Note that queues are only visible within a single CamelContext. If you want to communicate across CamelContext instances (for example, communicating between Web applications), see the VM component. This component does not implement any kind of persistence or recovery, if the VM terminates while messages are yet to be processed. If you need persistence, reliability or distributed SEDA, try using either JMS or ActiveMQ.
URI formatseda:someName[?options] Where someName can be any string that uniquely identifies the endpoint within the current CamelContext. You can append query options to the URI in the following format, ?option=value&option=value&...
Options
You can set these default value on seda component since Camel 2.9
Changes in Camel 2.0In Camel 2.0 the SEDA component supports using Request Reply, where the caller will wait for the Async route to complete. For instance: from("mina:tcp://0.0.0.0:9876?textline=true&sync=true").to("seda:input"); from("seda:input").to("bean:processInput").to("bean:createResponse"); In the route above, we have a TCP listener on port 9876 that accepts incoming requests. The request is routed to the seda:input queue. As it is a Request Reply message, we wait for the response. When the consumer on the seda:input queue is complete, it copies the response to the original message response. Camel 1.x does not have this feature implemented, the SEDA queues in Camel 1.x will never wait.
Concurrent consumersBy default, the SEDA endpoint uses a single consumer thread, but you can configure it to use concurrent consumer threads. So instead of thread pools you can use:
from("seda:stageName?concurrentConsumers=5").process(...)
Difference between thread pools and concurrent consumersThe thread pool is a pool that can increase/shrink dynamically at runtime depending on load, whereas the concurrent consumers are always fixed. Thread poolsBe aware that adding a thread pool to a SEDA endpoint by doing something like:
from("seda:stageName").thread(5).process(...)
Can wind up with two BlockQueues: one from the SEDA endpoint, and one from the workqueue of the thread pool, which may not be what you want. Instead, you might want to consider configuring a Direct endpoint with a thread pool, which can process messages both synchronously and asynchronously. For example:
from("direct:stageName").thread(5).process(...)
You can also directly configure number of threads that process messages on a SEDA endpoint using the concurrentConsumers option. SampleIn the route below we use the SEDA queue to send the request to this async queue to be able to send a fire-and-forget message for further processing in another thread, and return a constant reply in this thread to the original caller. public void configure() throws Exception { from("direct:start") // send it to the seda queue that is async .to("seda:next") // return a constant response .transform(constant("OK")); from("seda:next").to("mock:result"); } Here we send a Hello World message and expects the reply to be OK. Object out = template.requestBody("direct:start", "Hello World"); assertEquals("OK", out); The "Hello World" message will be consumed from the SEDA queue from another thread for further processing. Since this is from a unit test, it will be sent to a mock endpoint where we can do assertions in the unit test. Using multipleConsumersAvailable as of Camel 2.2 In this example we have defined two consumers and registered them as spring beans. <!-- define the consumers as spring beans --> <bean id="consumer1" class="org.apache.camel.spring.example.FooEventConsumer"/> <bean id="consumer2" class="org.apache.camel.spring.example.AnotherFooEventConsumer"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <!-- define a shared endpoint which the consumers can refer to instead of using url --> <endpoint id="foo" uri="seda:foo?multipleConsumers=true"/> </camelContext> Since we have specified multipleConsumers=true on the seda foo endpoint we can have those two consumers receive their own copy of the message as a kind of pub-sub style messaging. As the beans are part of an unit test they simply send the message to a mock endpoint, but notice how we can use @Consume to consume from the seda queue. public class FooEventConsumer { @EndpointInject(uri = "mock:result") private ProducerTemplate destination; @Consume(ref = "foo") public void doSomething(String body) { destination.sendBody("foo" + body); } } Extracting queue information.If you need it, you can also get information like queue size etc without using JMX like this: SedaEndpoint seda = context.getEndpoint("seda:xxxx"); int size = seda.getExchanges().size() See AlsoServlet ComponentAvailable as of Camel 2.0 The servlet: component provides HTTP based endpoints for consuming HTTP requests that arrive at a HTTP endpoint and this endpoint is bound to a published Servlet. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-servlet</artifactId> <version>x.x.x</version> <\!-\- use the same version as your Camel core version \--> </dependency> URI format
servlet://relative_path[?options]
You can append query options to the URI in the following format, ?option=value&option=value&... Options
Message HeadersCamel will apply the same Message Headers as the HTTP component. Camel will also populate all request.parameter and request.headers. For example, if a client request has the URL, http://myserver/myserver?orderid=123, the exchange will contain a header named orderid with the value 123. UsageYou can only consume from endpoints generated by the Servlet component. Therefore, it should only be used as input into your camel routes. To issue HTTP requests against other HTTP endpoints, use the HTTP Component Sample
In this sample, we define a route that exposes a HTTP service at http://localhost:8080/camel/services/hello. <web-app> <servlet> <servlet-name>CamelServlet</servlet-name> <display-name>Camel Http Transport Servlet</display-name> <servlet-class>org.apache.camel.component.servlet.CamelHttpTransportServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>CamelServlet</servlet-name> <url-pattern>/services/*</url-pattern> </servlet-mapping> </web-app> Then you can define your route as follows: from("servlet:///hello?matchOnUriPrefix=true").process(new Processor() { public void process(Exchange exchange) throws Exception { String contentType = exchange.getIn().getHeader(Exchange.CONTENT_TYPE, String.class); String path = exchange.getIn().getHeader(Exchange.HTTP_PATH, String.class); assertEquals("Get a wrong content type", CONTENT_TYPE, contentType); // assert camel http header String charsetEncoding = exchange.getIn().getHeader(Exchange.HTTP_CHARACTER_ENCODING, String.class); assertEquals("Get a wrong charset name from the message heaer", "UTF-8", charsetEncoding); // assert exchange charset assertEquals("Get a wrong charset naem from the exchange property", "UTF-8", exchange.getProperty(Exchange.CHARSET_NAME)); exchange.getOut().setHeader(Exchange.CONTENT_TYPE, contentType + "; charset=UTF-8"); exchange.getOut().setHeader("PATH", path); exchange.getOut().setBody("<b>Hello World</b>"); } });
Sample when using Spring 3.xSample when using Spring 2.xWhen using the Servlet component in a Camel/Spring application it's often required to load the Spring ApplicationContext after the Servlet component has started. This can be accomplished by using Spring's ContextLoaderServlet instead of ContextLoaderListener. In that case you'll need to start ContextLoaderServlet after CamelHttpTransportServlet like this: <web-app> <servlet> <servlet-name>CamelServlet</servlet-name> <servlet-class> org.apache.camel.component.servlet.CamelHttpTransportServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet> <servlet-name>SpringApplicationContext</servlet-name> <servlet-class> org.springframework.web.context.ContextLoaderServlet </servlet-class> <load-on-startup>2</load-on-startup> </servlet> <web-app> Sample when using OSGiFrom Camel 2.6.0, you can publish the CamelHttpTransportServlet as an OSGi service with help of SpringDM like this. <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:osgi="http://www.springframework.org/schema/osgi" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi.xsd"> <bean id="camelServlet" class="org.apache.camel.component.servlet.CamelHttpTransportServlet"> </bean> <!-- Enlist it in OSGi service registry This will cause two things: 1) As the pax web whiteboard extender is running the CamelServlet will be registered with the OSGi HTTP Service 2) It will trigger the HttpRegistry in other bundles so the servlet is made known there too --> <osgi:service ref="camelServlet"> <osgi:interfaces> <value>javax.servlet.Servlet</value> <value>org.apache.camel.component.http.CamelServlet</value> </osgi:interfaces> <osgi:service-properties> <entry key="alias" value="/camel/services" /> <entry key="matchOnUriPrefix" value="true" /> <entry key="servlet-name" value="CamelServlet"/> </osgi:service-properties> </osgi:service> </beans> Then use this service in your camel route like this: <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://camel.apache.org/schema/spring" xmlns:osgi="http://www.springframework.org/schema/osgi" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <osgi:reference id="servletref" interface="org.apache.camel.component.http.CamelServlet"> <osgi:listener bind-method="register" unbind-method="unregister"> <ref bean="httpRegistry"/> </osgi:listener> </osgi:reference> <bean id="httpRegistry" class="org.apache.camel.component.servlet.DefaultHttpRegistry"/> <bean id="servlet" class="org.apache.camel.component.servlet.ServletComponent"> <property name="httpRegistry" ref="httpRegistry" /> </bean> <bean id="servletProcessor" class="org.apache.camel.itest.osgi.servlet.ServletProcessor" /> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <!-- notice how we can use the servlet scheme which is that osgi:reference above --> <from uri="servlet:///hello"/> <process ref="servletProcessor"/> </route> </camelContext> </beans> For versions prior to Camel 2.6 you can use an Activator to publish the CamelHttpTransportServlet on the OSGi platform import java.util.Dictionary; import java.util.Hashtable; import org.apache.camel.component.servlet.CamelHttpTransportServlet; import org.osgi.framework.BundleActivator; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceReference; import org.osgi.service.http.HttpContext; import org.osgi.service.http.HttpService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.osgi.context.BundleContextAware; public final class ServletActivator implements BundleActivator, BundleContextAware { private static final transient Logger LOG = LoggerFactory.getLogger(ServletActivator.class); private static boolean registerService; /** * HttpService reference. */ private ServiceReference httpServiceRef; /** * Called when the OSGi framework starts our bundle */ public void start(BundleContext bc) throws Exception { registerServlet(bc); } /** * Called when the OSGi framework stops our bundle */ public void stop(BundleContext bc) throws Exception { if (httpServiceRef != null) { bc.ungetService(httpServiceRef); httpServiceRef = null; } } protected void registerServlet(BundleContext bundleContext) throws Exception { httpServiceRef = bundleContext.getServiceReference(HttpService.class.getName()); if (httpServiceRef != null && !registerService) { LOG.info("Register the servlet service"); final HttpService httpService = (HttpService)bundleContext.getService(httpServiceRef); if (httpService != null) { // create a default context to share between registrations final HttpContext httpContext = httpService.createDefaultHttpContext(); // register the hello world servlet final Dictionary<String, String> initParams = new Hashtable<String, String>(); initParams.put("matchOnUriPrefix", "false"); initParams.put("servlet-name", "CamelServlet"); httpService.registerServlet("/camel/services", // alias new CamelHttpTransportServlet(), // register servlet initParams, // init params httpContext // http context ); registerService = true; } } } public void setBundleContext(BundleContext bc) { try { registerServlet(bc); } catch (Exception e) { LOG.error("Cannot register the servlet, the reason is " + e); } } } See AlsoShiro Security ComponentAvailable as of Camel 2.5 The shiro-security component in Camel is a security focused component, based on the Apache Shiro security project. Apache Shiro is a powerful and flexible open-source security framework that cleanly handles authentication, authorization, enterprise session management and cryptography. The objective of the Apache Shiro project is to provide the most robust and comprehensive application security framework available while also being very easy to understand and extremely simple to use. This camel shiro-security component allows authentication and authorization support to be applied to different segments of a camel route. Shiro security is applied on a route using a Camel Policy. A Policy in Camel utilizes a strategy pattern for applying interceptors on Camel Processors. It offering the ability to apply cross-cutting concerns (for example. security, transactions etc) on sections/segments of a camel route. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-shiro</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> Shiro Security BasicsTo employ Shiro security on a camel route, a ShiroSecurityPolicy object must be instantiated with security configuration details (including users, passwords, roles etc). This object must then be applied to a camel route. This ShiroSecurityPolicy Object may also be registered in the Camel registry (JNDI or ApplicationContextRegistry) and then utilized on other routes in the Camel Context. Configuration details are provided to the ShiroSecurityPolicy using an Ini file (properties file) or an Ini object. The Ini file is a standard Shiro configuration file containing user/role details as shown below [users] # user 'ringo' with password 'starr' and the 'sec-level1' role ringo = starr, sec-level1 george = harrison, sec-level2 john = lennon, sec-level3 paul = mccartney, sec-level3 [roles] # 'sec-level3' role has all permissions, indicated by the # wildcard '*' sec-level3 = * # The 'sec-level2' role can do anything with access of permission # readonly (*) to help sec-level2 = zone1:* # The 'sec-level1' role can do anything with access of permission # readonly sec-level1 = zone1:readonly:* Instantiating a ShiroSecurityPolicy ObjectA ShiroSecurityPolicy object is instantiated as follows
private final String iniResourcePath = "classpath:shiro.ini";
private final byte[] passPhrase = {
(byte) 0x08, (byte) 0x09, (byte) 0x0A, (byte) 0x0B,
(byte) 0x0C, (byte) 0x0D, (byte) 0x0E, (byte) 0x0F,
(byte) 0x10, (byte) 0x11, (byte) 0x12, (byte) 0x13,
(byte) 0x14, (byte) 0x15, (byte) 0x16, (byte) 0x17};
List<permission> permissionsList = new ArrayList<permission>();
Permission permission = new WildcardPermission("zone1:readwrite:*");
permissionsList.add(permission);
final ShiroSecurityPolicy securityPolicy =
new ShiroSecurityPolicy(iniResourcePath, passPhrase, true, permissionsList);
ShiroSecurityPolicy Options
Applying Shiro Authentication on a Camel RouteThe ShiroSecurityPolicy, tests and permits incoming message exchanges containing a encrypted SecurityToken in the Message Header to proceed further following proper authentication. The SecurityToken object contains a Username/Password details that are used to determine where the user is a valid user.
protected RouteBuilder createRouteBuilder() throws Exception {
final ShiroSecurityPolicy securityPolicy =
new ShiroSecurityPolicy("classpath:shiro.ini", passPhrase);
return new RouteBuilder() {
public void configure() {
onException(UnknownAccountException.class).
to("mock:authenticationException");
onException(IncorrectCredentialsException.class).
to("mock:authenticationException");
onException(LockedAccountException.class).
to("mock:authenticationException");
onException(AuthenticationException.class).
to("mock:authenticationException");
from("direct:secureEndpoint").
to("log:incoming payload").
policy(securityPolicy).
to("mock:success");
}
};
}
Applying Shiro Authorization on a Camel RouteAuthorization can be applied on a camel route by associating a Permissions List with the ShiroSecurityPolicy. The Permissions List specifies the permissions necessary for the user to proceed with the execution of the route segment. If the user does not have the proper permission set, the request is not authorized to continue any further.
protected RouteBuilder createRouteBuilder() throws Exception {
final ShiroSecurityPolicy securityPolicy =
new ShiroSecurityPolicy("./src/test/resources/securityconfig.ini", passPhrase);
return new RouteBuilder() {
public void configure() {
onException(UnknownAccountException.class).
to("mock:authenticationException");
onException(IncorrectCredentialsException.class).
to("mock:authenticationException");
onException(LockedAccountException.class).
to("mock:authenticationException");
onException(AuthenticationException.class).
to("mock:authenticationException");
from("direct:secureEndpoint").
to("log:incoming payload").
policy(securityPolicy).
to("mock:success");
}
};
}
Creating a ShiroSecurityToken and injecting it into a Message ExchangeA ShiroSecurityToken object may be created and injected into a Message Exchange using a Shiro Processor called ShiroSecurityTokenInjector. An example of injecting a ShiroSecurityToken using a ShiroSecurityTokenInjector in the client is shown below
ShiroSecurityToken shiroSecurityToken = new ShiroSecurityToken("ringo", "starr");
ShiroSecurityTokenInjector shiroSecurityTokenInjector =
new ShiroSecurityTokenInjector(shiroSecurityToken, passPhrase);
from("direct:client").
process(shiroSecurityTokenInjector).
to("direct:secureEndpoint");
Sending Messages to routes secured by a ShiroSecurityPolicyMessages and Message Exchanges sent along the camel route where the security policy is applied need to be accompanied by a SecurityToken in the Exchange Header. The SecurityToken is an encrypted object that holds a Username and Password. The SecurityToken is encrypted using AES 128 bit security by default and can be changed to any cipher of your choice. Given below is an example of how a request may be sent using a ProducerTemplate in Camel along with a SecurityToken
@Test
public void testSuccessfulShiroAuthenticationWithNoAuthorization() throws Exception {
//Incorrect password
ShiroSecurityToken shiroSecurityToken = new ShiroSecurityToken("ringo", "stirr");
// TestShiroSecurityTokenInjector extends ShiroSecurityTokenInjector
TestShiroSecurityTokenInjector shiroSecurityTokenInjector =
new TestShiroSecurityTokenInjector(shiroSecurityToken, passPhrase);
successEndpoint.expectedMessageCount(1);
failureEndpoint.expectedMessageCount(0);
template.send("direct:secureEndpoint", shiroSecurityTokenInjector);
successEndpoint.assertIsSatisfied();
failureEndpoint.assertIsSatisfied();
}
SIP ComponentAvailable as of Camel 2.5 The sip component in Camel is a communication component, based on the Jain SIP implementation (available under the JCP license). Session Initiation Protocol (SIP) is an IETF-defined signaling protocol, widely used for controlling multimedia communication sessions such as voice and video calls over Internet Protocol (IP).The SIP protocol is an Application Layer protocol designed to be independent of the underlying transport layer; it can run on Transmission Control Protocol (TCP), User Datagram Protocol (UDP) or Stream Control Transmission Protocol (SCTP). The Jain SIP implementation supports TCP and UDP only. The Camel SIP component only supports the SIP Publish and Subscribe capability as described in the RFC3903 - Session Initiation Protocol (SIP) Extension for Event This camel component supports both producer and consumer endpoints. Camel SIP Producers (Event Publishers) and SIP Consumers (Event Subscribers) communicate event & state information to each other using an intermediary entity called a SIP Presence Agent (a stateful brokering entity). For SIP based communication, a SIP Stack with a listener must be instantiated on both the SIP Producer and Consumer (using separate ports if using localhost). This is necessary in order to support the handshakes & acknowledgements exchanged between the SIP Stacks during communication. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-sip</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatThe URI scheme for a sip endpoint is as follows: sip://johndoe@localhost:99999[?options] sips://johndoe@localhost:99999/[?options] This component supports producer and consumer endpoints for both TCP and UDP. You can append query options to the URI in the following format, ?option=value&option=value&... OptionsThe SIP Component offers an extensive set of configuration options & capability to create custom stateful headers needed to propagate state via the SIP protocol.
Registry based OptionsSIP requires a number of headers to be sent/received as part of a request. These SIP header can be enlisted in the Registry, such as in the Spring XML file. The values that could be passed in, are the following:
Sending Messages to/from a SIP endpointCreating a Camel SIP PublisherIn the example below, a SIP Publisher is created to send SIP Event publications to
producerTemplate.sendBodyAndHeader(
"sip://agent@localhost:5152?stackName=client&eventHeaderName=evtHdrName&eventId=evtid&fromUser=user2&fromHost=localhost&fromPort=3534",
"EVENT_A",
"REQUEST_METHOD",
Request.PUBLISH);
Creating a Camel SIP SubscriberIn the example below, a SIP Subscriber is created to receive SIP Event publications sent to
@Override protected RouteBuilder createRouteBuilder() throws Exception { return new RouteBuilder() { @Override public void configure() throws Exception { // Create PresenceAgent from("sip://agent@localhost:5152?stackName=PresenceAgent&presenceAgent=true&eventHeaderName=evtHdrName&eventId=evtid") .to("mock:neverland"); // Create Sip Consumer(Event Subscriber) from("sip://johndoe@localhost:5154?stackName=Subscriber&toUser=agent&toHost=localhost&toPort=5152&eventHeaderName=evtHdrName&eventId=evtid") .to("log:ReceivedEvent?level=DEBUG") .to("mock:notification"); } }; } The Camel SIP component also ships with a Presence Agent that is meant to be used for Testing and Demo purposes only. An example of instantiating a Presence Agent is given above. Note that the Presence Agent is set up as a user agent@localhost:5152 and is capable of communicating with both Publisher as well as Subscriber. It has a separate SIP stackName distinct from Publisher as well as Subscriber. While it is set up as a Camel Consumer, it does not actually send any messages along the route to the endpoint "mock:neverland". SMPP ComponentAvailable as of Camel 2.2 This component provides access to an SMSC (Short Message Service Center) over the SMPP protocol to send and receive SMS. The JSMPP is used. Starting with Camel 2.9, you are also able to execute ReplaceSm, QuerySm, SubmitMulti, CancelSm and DataSm. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-smpp</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatsmpp://[username@]hostname[:port][?options] smpps://[username@]hostname[:port][?options] If no username is provided, then Camel will provide the default value smppclient. You can append query options to the URI in the following format, ?option=value&option=value&... URI Options
You can have as many of these options as you like.
smpp://smppclient@localhost:2775?password=password&enquireLinkTimer=3000&transactionTimer=5000&systemType=consumer
Message HeadersThe following message headers can be used to affect the behavior of the SMPP producer
The following message headers are used by the SMPP producer to set the response from the SMSC in the message header
The following message headers are used by the SMPP consumer to set the request data from the SMSC in the message header
Exception handlingThis component supports the general Camel exception handling capabilities. from("smpp://smppclient@localhost:2775?password=password&enquireLinkTimer=3000&transactionTimer=5000&systemType=consumer") .doTry() .to("bean:dao?method=updateSmsState") .doCatch(Exception.class) .throwException(new ProcessRequestException("update of sms state failed", 100)) .end(); Please refer to the SMPP specification for the complete list of error codes and their meanings. SamplesA route which sends an SMS using the Java DSL: from("direct:start") .to("smpp://smppclient@localhost:2775? password=password&enquireLinkTimer=3000&transactionTimer=5000&systemType=producer"); A route which sends an SMS using the Spring XML DSL: <route> <from uri="direct:start"/> <to uri="smpp://smppclient@localhost:2775? password=password&enquireLinkTimer=3000&transactionTimer=5000&systemType=producer"/> </route> A route which receives an SMS using the Java DSL: from("smpp://smppclient@localhost:2775?password=password&enquireLinkTimer=3000&transactionTimer=5000&systemType=consumer") .to("bean:foo"); A route which receives an SMS using the Spring XML DSL: <route> <from uri="smpp://smppclient@localhost:2775? password=password&enquireLinkTimer=3000&transactionTimer=5000&systemType=consumer"/> <to uri="bean:foo"/> </route>
Debug loggingThis component has log level DEBUG, which can be helpful in debugging problems. If you use log4j, you can add the following line to your configuration: log4j.logger.org.apache.camel.component.smpp=DEBUG See AlsoSNMP ComponentAvailable as of Camel 2.1 The snmp: component gives you the ability to poll SNMP capable devices or receiving traps. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-snmp</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format
snmp://hostname[:port][?Options]
The component supports polling OID values from an SNMP enabled device and receiving traps. You can append query options to the URI in the following format, ?option=value&option=value&... Options
The result of a pollGiven the situation, that I poll for the following OIDs: OIDs 1.3.6.1.2.1.1.3.0 1.3.6.1.2.1.25.3.2.1.5.1 1.3.6.1.2.1.25.3.5.1.1.1 1.3.6.1.2.1.43.5.1.1.11.1 The result will be the following: Result of toString conversion <?xml version="1.0" encoding="UTF-8"?> <snmp> <entry> <oid>1.3.6.1.2.1.1.3.0</oid> <value>6 days, 21:14:28.00</value> </entry> <entry> <oid>1.3.6.1.2.1.25.3.2.1.5.1</oid> <value>2</value> </entry> <entry> <oid>1.3.6.1.2.1.25.3.5.1.1.1</oid> <value>3</value> </entry> <entry> <oid>1.3.6.1.2.1.43.5.1.1.11.1</oid> <value>6</value> </entry> <entry> <oid>1.3.6.1.2.1.1.1.0</oid> <value>My Very Special Printer Of Brand Unknown</value> </entry> </snmp> As you maybe recognized there is one more result than requested....1.3.6.1.2.1.1.1.0. ExamplesPolling a remote device: snmp:192.168.178.23:161?protocol=udp&type=POLL&oids=1.3.6.1.2.1.1.5.0 Setting up a trap receiver (Note that no OID info is needed here!): snmp:127.0.0.1:162?protocol=udp&type=TRAP Routing example in Java: (converts the SNMP PDU to XML String) from("snmp:192.168.178.23:161?protocol=udp&type=POLL&oids=1.3.6.1.2.1.1.5.0"). convertBodyTo(String.class). to("activemq:snmp.states"); See AlsoSpring Integration ComponentThe spring-integration: component provides a bridge for Camel components to talk to spring integration endpoints. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring-integration</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI formatspring-integration:defaultChannelName[?options] Where defaultChannelName represents the default channel name which is used by the Spring Integration Spring context. It will equal to the inputChannel name for the Spring Integration consumer and the outputChannel name for the Spring Integration provider. You can append query options to the URI in the following format, ?option=value&option=value&... Options
UsageThe Spring integration component is a bridge that connects Camel endpoints with Spring integration endpoints through the Spring integration's input channels and output channels. Using this component, we can send Camel messages to Spring Integration endpoints or receive messages from Spring integration endpoints in a Camel routing context. ExamplesUsing the Spring integration endpointYou can set up a Spring integration endpoint using a URI, as follows: <beans:beans xmlns="http://www.springframework.org/schema/integration" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <!-- spring integration channels --> <channel id="inputChannel"/> <channel id="outputChannel"/> <channel id="onewayChannel"/> <!-- spring integration service activators --> <service-activator input-channel="inputChannel" ref="helloService" method="sayHello"/> <service-activator input-channel="onewayChannel" ref="helloService" method="greet"/> <!-- custom bean --> <beans:bean id="helloService" class="org.apache.camel.component.spring.integration.HelloWorldService"/> <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:twowayMessage"/> <to uri="spring-integration:inputChannel?inOut=true&inputChannel=outputChannel"/> </route> <route> <from uri="direct:onewayMessage"/> <to uri="spring-integration:onewayChannel?inOut=false"/> </route> </camelContext> <!-- spring integration channels --> <channel id="requestChannel"/> <channel id="responseChannel"/> <!-- cusom Camel processor --> <beans:bean id="myProcessor" class="org.apache.camel.component.spring.integration.MyProcessor"/> <!-- Camel route --> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="spring-integration://requestChannel?outputChannel=responseChannel&inOut=true"/> <process ref="myProcessor"/> </route> </camelContext> Or directly using a Spring integration channel name: <beans:beans xmlns="http://www.springframework.org/schema/integration" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd"> <!-- spring integration channel --> <channel id="outputChannel"/> <camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="outputChannel"/> <to uri="mock:result"/> </route> </camelContext> The Source and Target adapterSpring integration also provides the Spring integration's source and target adapters, which can route messages from a Spring integration channel to a Camel endpoint or from a Camel endpoint to a Spring integration channel. This example uses the following namespaces: <beans:beans xmlns="http://www.springframework.org/schema/integration" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel-si="http://camel.apache.org/schema/spring/integration" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd http://camel.apache.org/schema/spring/integration http://camel.apache.org/schema/spring/integration/camel-spring-integration.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd "> You can bind your source or target to a Camel endpoint as follows: <!-- Create the camel context here --> <camelContext id="camelTargetContext" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:EndpointA" /> <to uri="mock:result" /> </route> <route> <from uri="direct:EndpointC"/> <process ref="myProcessor"/> </route> </camelContext> <!-- We can bind the camelTarget to the camel context's endpoint by specifying the camelEndpointUri attribute --> <camel-si:camelTarget id="camelTargetA" camelEndpointUri="direct:EndpointA" expectReply="false"> <camel-si:camelContextRef>camelTargetContext</camel-si:camelContextRef> </camel-si:camelTarget> <camel-si:camelTarget id="camelTargetB" camelEndpointUri="direct:EndpointC" replyChannel="channelC" expectReply="true"> <camel-si:camelContextRef>camelTargetContext</camel-si:camelContextRef> </camel-si:camelTarget> <camel-si:camelTarget id="camelTargetD" camelEndpointUri="direct:EndpointC" expectReply="true"> <camel-si:camelContextRef>camelTargetContext</camel-si:camelContextRef> </camel-si:camelTarget> <beans:bean id="myProcessor" class="org.apache.camel.component.spring.integration.MyProcessor"/> <!-- spring integration channels --> <channel id="channelA"/> <channel id="channelB"/> <channel id="channelC"/> <!-- spring integration service activator --> <service-activator input-channel="channelB" output-channel="channelC" ref="helloService" method="sayHello"/> <!-- custom bean --> <beans:bean id="helloService" class="org.apache.camel.component.spring.integration.HelloWorldService"/> <camelContext id="camelSourceContext" xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="direct:OneWay"/> <to uri="direct:EndpointB"/> </route> <route> <from uri="direct:TwoWay"/> <to uri="direct:EndpointC"/> </route> </camelContext> <!-- camelSource will redirect the message coming for direct:EndpointB to the spring requestChannel channelA --> <camel-si:camelSource id="camelSourceA" camelEndpointUri="direct:EndpointB" requestChannel="channelA" expectReply="false"> <camel-si:camelContextRef>camelSourceContext</camel-si:camelContextRef> </camel-si:camelSource> <!-- camelSource will redirect the message coming for direct:EndpointC to the spring requestChannel channelB then it will pull the response from channelC and put the response message back to direct:EndpointC --> <camel-si:camelSource id="camelSourceB" camelEndpointUri="direct:EndpointC" requestChannel="channelB" replyChannel="channelC" expectReply="true"> <camel-si:camelContextRef>camelSourceContext</camel-si:camelContextRef> </camel-si:camelSource> See AlsoSpring Web Services ComponentAvailable as of Camel 2.6 The spring-ws: component allows you to integrate with Spring Web Services. It offers both client-side support, for accessing web services, and server-side support for creating your own contract-first web services. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring-ws</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
URI formatThe URI scheme for this component is as follows spring-ws:[mapping-type:]address[?options] To expose a web service mapping-type needs to be set to any of the following:
As a consumer the address should contain a value relevant to the specified mapping-type (e.g. a SOAP action, XPath expression). As a producer the address should be set to the URI of the web service your calling upon. You can append query options to the URI in the following format, ?option=value&option=value&... Options
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