Chapter 79. CXF-RS Component

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?resourceClasses=org.apache.camel.rs.Example

The CXF-RS component supports 3 options, which are listed below.

The CXF-RS endpoint is configured using URI syntax:

cxfrs:beanId:address

with the following path and query parameters:

The component supports 4 options, which are listed below.

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. Please check out the schema file and CXF JAX-RS documentation for more information.

In camel-cxf schema file, there are two elements for the REST endpoint definition. cxf:rsServer for REST consumer, cxf:rsClient for REST producer.
You can find a Camel REST service route configuration example here.

The camel-cxfrs producer supports to override the services address by setting the message with the key of "CamelDestinationOverrideUrl".

 // set up the service address from the message header to override the setting of CXF endpoint
 exchange.getIn().setHeader(Exchange.DESTINATION_OVERRIDE_URL, constant(getServiceAddress()));

Available as of Camel 2.11

The Default binding style is rather low-level, requiring the user to manually process the MessageContentsList object coming into the route. Thus, it tightly couples the route logic with the method signature and parameter indices of the JAX-RS operation. Somewhat inelegant, difficult and error-prone.

In contrast, the SimpleConsumer binding style performs the following mappings, in order to make the request data more accessible to you within the Camel Message:

Additionally, the following rules apply to the Response mapping:

  from("cxfrs:bean:rsServer?bindingStyle=SimpleConsumer")
    .to("log:TEST?showAll=true");

@POST @Path("/customers/{type}")
public Response newCustomer(Customer customer, @PathParam("type") String type, @QueryParam("active") @DefaultValue("true") boolean active) {
    return null;
}

from("cxfrs:bean:rsServer?bindingStyle=SimpleConsumer")
    .recipientList(simple("direct:${header.operationName}"));

from("direct:newCustomer")
    .log("Request: type=${header.type}, active=${header.active}, customerData=${body}");

POST /customers/gold?active=true

Payload:
<Customer>
  <fullName>Raul Kripalani</fullName>
  <country>Spain</country>
  <project>Apache Camel</project>
</Customer>

Request: type=gold, active=true, customerData=<Customer.toString() representation>

The CXF JAXRS front end implements the JAX-RS (JSR-311) 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. Unlike the Camel Restlet component, you don’t need to specify the URI template within your endpoint, CXF takes care of the REST request URI to resource class method mapping according to the JSR-311 specification. All you need to do in Camel is delegate this method request to a right processor or endpoint.

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";
private static final String CXF_RS_ENDPOINT_URI2 =
        "cxfrs://http://localhost:" + CXT + "/rest2?resourceClasses=org.apache.camel.component.cxf.jaxrs.testbean.CustomerService";
private static final String CXF_RS_ENDPOINT_URI3 =
        "cxfrs://http://localhost:" + CXT + "/rest3?"
        + "resourceClasses=org.apache.camel.component.cxf.jaxrs.testbean.CustomerServiceNoAnnotations&"
        + "modelRef=classpath:/org/apache/camel/component/cxf/jaxrs/CustomerServiceModel.xml";
private static final String CXF_RS_ENDPOINT_URI4 =
        "cxfrs://http://localhost:" + CXT + "/rest4?"
        + "modelRef=classpath:/org/apache/camel/component/cxf/jaxrs/CustomerServiceDefaultHandlerModel.xml";
private static final String CXF_RS_ENDPOINT_URI5 =
        "cxfrs://http://localhost:" + CXT + "/rest5?"
        + "propagateContexts=true&"
        + "modelRef=classpath:/org/apache/camel/component/cxf/jaxrs/CustomerServiceDefaultHandlerModel.xml";
protected RouteBuilder createRouteBuilder() throws Exception {
    final Processor testProcessor = new TestProcessor();
    final Processor testProcessor2 = new TestProcessor2();
    final Processor testProcessor3 = new TestProcessor3();
    return new RouteBuilder() {
        public void configure() {
            errorHandler(new NoErrorHandlerBuilder());
            from(CXF_RS_ENDPOINT_URI).process(testProcessor);
            from(CXF_RS_ENDPOINT_URI2).process(testProcessor);
            from(CXF_RS_ENDPOINT_URI3).process(testProcessor);
            from(CXF_RS_ENDPOINT_URI4).process(testProcessor2);
            from(CXF_RS_ENDPOINT_URI5).process(testProcessor3);
        }
    };
}

And the corresponding resource class used to configure the endpoint…​

INFO:*Note about resource classes*

By default, JAX-RS resource classes are only*used to configure JAX-RS properties. Methods will *not be executed during routing of messages to the endpoint. Instead, it is the responsibility of the route to do all processing.

Note that starting from Camel 2.15 it is also sufficient to provide an interface only as opposed to a no-op service implementation class for the default mode.

Starting from Camel 2.15, if a performInvocation option is enabled, the service implementation will be invoked first, the response will be set on the Camel exchange and the route execution will continue as usual. This can be useful for integrating the existing JAX-RS implementations into Camel routes and for post-processing JAX-RS Responses in custom processors.

@Path("/customerservice/")
public interface CustomerServiceResource {

    @GET
    @Path("/customers/{id}/")
    Customer getCustomer(@PathParam("id") String id);

    @PUT
    @Path("/customers/")
    Response updateCustomer(Customer customer);

    @Path("/{id}")
    @PUT()
    @Consumes({ "application/xml", "text/plain",
                    "application/json" })
    @Produces({ "application/xml", "text/plain",
                    "application/json" })
    Object invoke(@PathParam("id") String id,
                    String payload);
}

The CXF JAXRS front end implements a proxy-based client API, with this API you can invoke the remote REST service through a proxy. The camel-cxfrs producer is based on this proxy API. You just need to specify the operation name in the message header and prepare the parameter in the message body, the camel-cxfrs producer will generate right REST request for you.

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();
        // 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 a customer header
        inMessage.setHeader("key", "value");
        // setup the accept content type
        inMessage.setHeader(Exchange.ACCEPT_CONTENT_TYPE, "application/json");
        // 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 ", 123, response.getId());
assertEquals("Get a wrong customer name", "John", response.getName());
assertEquals("Get a wrong response code", 200, exchange.getOut().getHeader(Exchange.HTTP_RESPONSE_CODE));
assertEquals("Get a wrong header value", "value", exchange.getOut().getHeader("key"));

The 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 the HTTP_METHOD and let the producer use the http centric client API by using the URI option httpClientAPI or by setting the message header CxfConstants.CAMEL_CXF_RS_USING_HTTP_API. You can turn the response object to the type class specified with the message header 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();
        // 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);
        // set a customer header
        inMessage.setHeader("key", "value");
        // since we use the Get method, so we don't need to set the message body
        inMessage.setBody(null);
    }
});

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:9003/testQuery?httpClientAPI=true&q1=12&q2=13"

To support the Dynamical routing, you can override the URI’s query parameters by using the CxfConstants.CAMEL_CXF_RS_QUERY_MAP header to set the parameter map for it.

Map<String, String> queryMap = new LinkedHashMap<>();
queryMap.put("q1", "new");
queryMap.put("q2", "world");
inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_QUERY_MAP, queryMap);

In CXF you offer or consume a webservice by defining its address. The first part of the address specifies the protocol to use. For example address="http://localhost:9000" 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 easily use Camel’s routing engine and integration patterns support together with your CXF services.

To include the Camel Tranport into your CXF bus you use the CamelTransportFactory. You can do this in Java as well as in Spring.

<!-- you don't need to specify the CamelTransportFactory configuration as it is auto load by CXF bus -->
<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>

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();
// set up the CamelContext which will be use by the CamelTransportFactory
camelTransportFactory.setCamelContext(context)
// if you are using CXF higher then 2.4.x the
camelTransportFactory.setBus(bus);

// if you are lower CXF, you need to register the ConduitInitiatorManager and DestinationFactoryManager like below
// 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);

From Camel 2.11.x, Camel Transport supports to be configured with Blueprint.

If you are using blueprint, you should use the namespace http://cxf.apache.org/transports/camel/blueprint and import the schema like the blow.

Adding the Configuration Namespace for blueprint

<beans ...
       xmlns:camel="http://cxf.apache.org/transports/camel/blueprint"
       ...
       xsi:schemaLocation="...
                           http://cxf.apache.org/transports/camel/blueprint
                           http://cxf.apache.org/schmemas/blueprint/camel.xsd
                          ...>

In blueprint camel:conduit camel:destination only has one camelContextId attribute, they doesn’t support to specify the camel context in the camel destination.

  <camel:conduit id="*.camel-conduit" camelContextId="camel1" />
  <camel:destination id="*.camel-destination" camelContextId="camel1" />

This example shows how to use the camel load balancing feature in CXF. You need to load the configuration file in CXF and publish the endpoints on the address "camel://direct:EndpointA" and "camel://direct:EndpointB"

Better JMS Transport for CXF Webservice using Apache Camel