Routebox Component

Table of Contents

The need for a Camel Routebox endpoint
URI format
Options
Sending/Receiving Messages to/from the routebox

Available as of Camel 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

The routebox component supports both consumer and producer endpoints.

Producer endpoints are of two flavors

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 AreaCoarse 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 component supports 18 endpoint options which are listed below:

{% raw %}

NameGroupDefaultJava TypeDescription

routeboxName

common

 

String

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

dispatchMap

common

 

Map

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.

dispatchStrategy

common

 

RouteboxDispatchStrategy

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

forkContext

common

true

boolean

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

innerProtocol

common

direct

String

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

queueSize

common

 

int

Create a fixed size queue to receive requests.

bridgeErrorHandler

consumer

false

boolean

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/ERROR level and ignored.

pollInterval

consumer

1000

long

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.

threads

consumer

20

int

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

exceptionHandler

consumer (advanced)

 

ExceptionHandler

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

exchangePattern

consumer (advanced)

 

ExchangePattern

Sets the exchange pattern when the consumer creates an exchange.

connectionTimeout

producer

20000

long

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

sendToConsumer

producer

true

boolean

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.

innerContext

advanced

 

CamelContext

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.

innerProducerTemplate

advanced

 

ProducerTemplate

The ProducerTemplate to use by the internal embeded CamelContext

innerRegistry

advanced

 

Registry

To use a custom registry for the internal embedded CamelContext.

routeBuilders

advanced

 

String

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

synchronous

advanced

false

boolean

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

{% endraw %}

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");