Class

Since Camel 2.4

Only producer is supported

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 format

class:className[?options]

Where className is the fully qualified class name to create and use as bean.

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

The following two sections list all the options, firstly for the component followed by the endpoint.

Component Options

The Class component supports 4 options, which are listed below.

Name Description Default Type

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

scope (producer)

Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using delegate scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry.

Enum values:

  • Singleton

  • Request

  • Prototype

Singleton

BeanScope

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

beanInfoCacheSize (advanced)

Maximum cache size of internal cache for bean introspection. Setting a value of 0 or negative will disable the cache.

1000

int

Endpoint Options

The Class endpoint is configured using URI syntax:

class:beanName

With the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

beanName (common)

Required Sets the name of the bean to invoke.

String

Query Parameters (4 parameters)

Name Description Default Type

method (common)

Sets the name of the method to invoke on the bean.

String

scope (common)

Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using prototype scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry.

Enum values:

  • Singleton

  • Request

  • Prototype

Singleton

BeanScope

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

parameters (advanced)

Used for configuring additional properties on the bean.

Map

Message Headers

The Class component supports 1 message header(s), which is/are listed below:

Name Description Default Type

CamelBeanMethodName (producer)

Constant: BEAN_METHOD_NAME

The name of the method to invoke.

String

Using

You simply use the class component just as the Bean component but by specifying the fully qualified class name instead. For example to use the MyFooBean you have to do as follows:

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 instance

In 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?bean.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?bean.cool=#foo")
    .to("mock:result");

Which will look up a bean from the Registry with the id foo and invoke the setCool method on the created instance of the MyPrefixBean class.

See more details on the Bean component as the class component works in much the same way.

Spring Boot Auto-Configuration

When using class with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-bean-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 14 options, which are listed below.

Name Description Default Type

camel.component.bean.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.bean.bean-info-cache-size

Maximum cache size of internal cache for bean introspection. Setting a value of 0 or negative will disable the cache.

1000

Integer

camel.component.bean.enabled

Whether to enable auto configuration of the bean component. This is enabled by default.

Boolean

camel.component.bean.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.bean.scope

Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using delegate scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry.

BeanScope

camel.component.class.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.class.bean-info-cache-size

Maximum cache size of internal cache for bean introspection. Setting a value of 0 or negative will disable the cache.

1000

Integer

camel.component.class.enabled

Whether to enable auto configuration of the class component. This is enabled by default.

Boolean

camel.component.class.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.class.scope

Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using delegate scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. so when using prototype then this depends on the delegated registry.

BeanScope

camel.language.bean.enabled

Whether to enable auto configuration of the bean language. This is enabled by default.

Boolean

camel.language.bean.scope

Scope of bean. When using singleton scope (default) the bean is created or looked up only once and reused for the lifetime of the endpoint. The bean should be thread-safe in case concurrent threads is calling the bean at the same time. When using request scope the bean is created or looked up once per request (exchange). This can be used if you want to store state on a bean while processing a request and you want to call the same bean instance multiple times while processing the request. The bean does not have to be thread-safe as the instance is only called from the same request. When using prototype scope, then the bean will be looked up or created per call. However in case of lookup then this is delegated to the bean registry such as Spring or CDI (if in use), which depends on their configuration can act as either singleton or prototype scope. So when using prototype scope then this depends on the bean registry implementation.

Singleton

String

camel.language.bean.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.bean.validate

Whether to validate the bean has the configured method.

true

Boolean