RouteBox Component (deprecated)

Available as of Camel version 2.6

Routebox subject for change

The Routebox component will be revisited in upcoming releases to see if it can be further simplified, be more intuitive and user friendly. The related Context component may be regardes as the simpler component. This component may be @deprecated in favor of Context.

The routebox component enables the creation of specialized endpoints that offer encapsulation and a strategy based indirection service to a collection of camel routes hosted in an automatically created or user injected camel context.

Routebox endpoints are camel endpoints that may be invoked directly on camel routes. The routebox endpoint performs the following key functions

  • encapsulation - acts as a blackbox, hosting a collection of camel routes stored in an inner camel context. The inner context is fully under the control of the routebox component and is JVM bound.

  • strategy based indirection - direct payloads sent to the routebox endpoint along a camel route to specific inner routes based on a user defined internal routing strategy or a dispatch map.

  • exchange propagation - forward exchanges modified by the routebox endpoint to the next segment of the camel route.

The routebox component supports both consumer and producer endpoints.

Producer endpoints are of two flavors

  • Producers that send or dispatch incoming requests to a external routebox consumer endpoint

  • Producers that directly invoke routes in an internal embedded camel context thereby not sending requests to an external consumer.

Maven users will need to add the following dependency to their pom.xml for this component:

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

The need for a Camel Routebox endpoint

The routebox component is designed to ease integration in complex environments needing

  • a large collection of routes and

  • involving a wide set of endpoint technologies needing integration in different ways

In such environments, it is often necessary to craft an integration solution by creating a sense of layering among camel routes effectively organizing them into

  • Coarse grained or higher level routes - aggregated collection of inner or lower level routes exposed as Routebox endpoints that represent an integration focus area. For example

Focus Area Coarse grained Route Examples

Department Focus

HR routes, Sales routes etc

Supply chain & B2B Focus

Shipping routes, Fulfillment routes, 3rd party services etc

Technology Focus

Database routes, JMS routes, Scheduled batch routes etc

  • Fine grained routes - routes that execute a singular and specific business and/or integration pattern.

Requests sent to Routebox endpoints on coarse grained routes can then delegate requests to inner fine grained routes to achieve a specific integration objective, collect the final inner result, and continue to progress to the next step along the coarse-grained route.

URI format

routebox:routeboxname[?options]

You can append query options to the URI in the following format, ?option=value&option=value&…​

Options

The RouteBox component has no options.

The RouteBox endpoint is configured using URI syntax:

routebox:routeboxName

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

routeboxName

Required Logical name for the routebox (eg like a queue name)

String

Query Parameters (17 parameters):

Name Description Default Type

dispatchMap (common)

A string representing a key in the Camel Registry matching an object value of the type HashMap. The HashMap key should contain strings that can be matched against the value set for the exchange header ROUTE_DISPATCH_KEY. The HashMap value should contain inner route consumer URI’s to which requests should be directed.

Map

dispatchStrategy (common)

To use a custom RouteboxDispatchStrategy which allows to use custom dispatching instead of the default.

RouteboxDispatch Strategy

forkContext (common)

Whether to fork and create a new inner CamelContext instead of reusing the same CamelContext.

true

boolean

innerProtocol (common)

The Protocol used internally by the Routebox component. Can be Direct or SEDA. The Routebox component currently offers protocols that are JVM bound.

direct

String

queueSize (common)

Create a fixed size queue to receive requests.

int

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

pollInterval (consumer)

The timeout used when polling from seda. When a timeout occurs, the consumer can check whether it is allowed to continue running. Setting a lower value allows the consumer to react more quickly upon shutdown.

1000

long

threads (consumer)

Number of threads to be used by the routebox to receive requests.

20

int

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer)

Sets the exchange pattern when the consumer creates an exchange.

ExchangePattern

connectionTimeout (producer)

Timeout in millis used by the producer when sending a message.

20000

long

sendToConsumer (producer)

Dictates whether a Producer endpoint sends a request to an external routebox consumer. If the setting is false, the Producer creates an embedded inner context and processes requests internally.

true

boolean

innerContext (advanced)

A string representing a key in the Camel Registry matching an object value of the type org.apache.camel.CamelContext. If a CamelContext is not provided by the user a CamelContext is automatically created for deployment of inner routes.

CamelContext

innerProducerTemplate (advanced)

The ProducerTemplate to use by the internal embeded CamelContext

ProducerTemplate

innerRegistry (advanced)

To use a custom registry for the internal embedded CamelContext.

Registry

routeBuilders (advanced)

A string representing a key in the Camel Registry matching an object value of the type List. If the user does not supply an innerContext pre-primed with inner routes, the routeBuilders option must be provided as a non-empty list of RouteBuilders containing inner routes

String

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

Spring Boot Auto-Configuration

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

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

The component supports 2 options, which are listed below.

Name Description Default Type

camel.component.routebox.enabled

Enable routebox component

true

Boolean

camel.component.routebox.resolve-property-placeholders

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

Boolean

Sending/Receiving Messages to/from the routebox

Before sending requests it is necessary to properly configure the routebox by loading the required URI parameters into the Registry as shown below. In the case of Spring, if the necessary beans are declared correctly, the registry is automatically populated by Camel.

Step 1: Loading inner route details into the Registry

@Override
protected JndiRegistry createRegistry() throws Exception {
    JndiRegistry registry = new JndiRegistry(createJndiContext());

    // Wire the routeDefinitions & dispatchStrategy to the outer camelContext where the routebox is declared
    List<RouteBuilder> routes = new ArrayList<RouteBuilder>();
    routes.add(new SimpleRouteBuilder());
    registry.bind("registry", createInnerRegistry());
    registry.bind("routes", routes);

    // Wire a dispatch map to registry
    HashMap<String, String> map = new HashMap<String, String>();
    map.put("addToCatalog", "seda:addToCatalog");
    map.put("findBook", "seda:findBook");
    registry.bind("map", map);

    // Alternatively wiring a dispatch strategy to the registry
    registry.bind("strategy", new SimpleRouteDispatchStrategy());

    return registry;
}

private JndiRegistry createInnerRegistry() throws Exception {
    JndiRegistry innerRegistry = new JndiRegistry(createJndiContext());
    BookCatalog catalogBean = new BookCatalog();
    innerRegistry.bind("library", catalogBean);

    return innerRegistry;
}
...
CamelContext context = new DefaultCamelContext(createRegistry());

Step 2: Optionaly using a Dispatch Strategy instead of a Dispatch Map

Using a dispatch Strategy involves implementing the interface org.apache.camel.component.routebox.strategy.RouteboxDispatchStrategy as shown in the example below.

public class SimpleRouteDispatchStrategy implements RouteboxDispatchStrategy {

    /* (non-Javadoc)
     * @see org.apache.camel.component.routebox.strategy.RouteboxDispatchStrategy#selectDestinationUri(java.util.List, org.apache.camel.Exchange)
     */
    public URI selectDestinationUri(List<URI> activeDestinations,
            Exchange exchange) {
        URI dispatchDestination = null;

        String operation = exchange.getIn().getHeader("ROUTE_DISPATCH_KEY", String.class);
        for (URI destination : activeDestinations) {
            if (destination.toASCIIString().equalsIgnoreCase("seda:" + operation)) {
                dispatchDestination = destination;
                break;
            }
        }

        return dispatchDestination;
    }
}

Step 2: Launching a routebox consumer

When creating a route consumer, note that the # entries in the routeboxUri are matched to the created inner registry, routebuilder list and dispatchStrategy/dispatchMap in the CamelContext Registry. Note that all routebuilders and associated routes are launched in the routebox created inner context

private String routeboxUri = "routebox:multipleRoutes?innerRegistry=#registry&routeBuilders=#routes&dispatchMap=#map";

public void testRouteboxRequests() throws Exception {
    CamelContext context = createCamelContext();
    template = new DefaultProducerTemplate(context);
    template.start();

    context.addRoutes(new RouteBuilder() {
        public void configure() {
            from(routeboxUri)
                .to("log:Routes operation performed?showAll=true");
        }
    });
    context.start();

    // Now use the ProducerTemplate to send the request to the routebox
    template.requestBodyAndHeader(routeboxUri, book, "ROUTE_DISPATCH_KEY", "addToCatalog");
}

Step 3: Using a routebox producer

When sending requests to the routebox, it is not necessary for producers do not need to know the inner route endpoint URI and they can simply invoke the Routebox URI endpoint with a dispatch strategy or dispatchMap as shown below

It is necessary to set a special exchange Header called ROUTE_DISPATCH_KEY (optional for Dispatch Strategy) with a key that matches a key in the dispatch map so that the request can be sent to the correct inner route

from("direct:sendToStrategyBasedRoutebox")
    .to("routebox:multipleRoutes?innerRegistry=#registry&routeBuilders=#routes&dispatchStrategy=#strategy")
    .to("log:Routes operation performed?showAll=true");

from ("direct:sendToMapBasedRoutebox")
    .setHeader("ROUTE_DISPATCH_KEY", constant("addToCatalog"))
    .to("routebox:multipleRoutes?innerRegistry=#registry&routeBuilders=#routes&dispatchMap=#map")
    .to("log:Routes operation performed?showAll=true");