Chapter 285. RouteBox Component (deprecated)
Available as of Camel version 2.6
Routebox subject for change
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>285.1. 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.
285.2. URI format
routebox:routeboxname[?options]
You can append query options to the URI in the following format, ?option=value&option=value&…
285.3. Options
The RouteBox component has no options.
The RouteBox endpoint is configured using URI syntax:
routebox:routeboxName
with the following path and query parameters:
285.3.1. Path Parameters (1 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| routeboxName | Required Logical name for the routebox (eg like a queue name) | String |
285.3.2. 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 |
285.4. Spring Boot Auto-Configuration
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 |
285.5. 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.
285.5.1. 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());285.5.2. 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;
}
}285.5.3. 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");
}285.5.4. 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");