Chapter 20. CXFRS
CXFRS Component
The cxfrs: component provides integration with Apache CXF for connecting to JAX-RS services hosted in CXF.
Maven users will need to add the following dependency to their
pom.xml for this component:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-cxf</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
Note
When using CXF as a consumer, the CAMEL:CXF Bean Component allows you to factor out how message payloads are received from their processing as a RESTful or SOAP web service. This has the potential of using a multitude of transports to consume web services. The bean component's configuration is also simpler and provides the fastest method to implement web services using Camel and CXF.
URI format
cxfrs://address?options
Where address represents the CXF endpoint's address
cxfrs:bean:rsEndpoint
Where rsEndpoint represents the Spring bean's name which represents 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
Options
| Name | Description | Example | Required? | default value |
|---|---|---|---|---|
resourceClasses
|
The resource classes which you want to export as REST service. Multiple classes can be separated by a comma. |
resourceClasses=org.apache.camel.rs.Example1,org.apache.camel.rs.Exchange2
|
No | None |
httpClientAPI
|
New to Apache Camel 2.1 If it is true, the CxfRsProducer will use the HttpClientAPI to invoke the service |
httpClientAPI=true
|
No |
true
|
synchronous
|
New in 2.5, this option will let CxfRsConsumer decide to use sync or async API to do the underlying work. The default value is false which means it will try to use async API by default. |
synchronous=true
|
No |
false
|
throwExceptionOnFailure
|
New in 2.6, this option tells the CxfRsProducer to inspect return codes and will generate an Exception if the return code is larger than 207. |
throwExceptionOnFailure=true
|
No |
true
|
maxClientCacheSize
|
New in 2.6, you can set the In message header, CamelDestinationOverrideUrl, to dynamically override the target destination Web Service or REST Service defined in your routes. The implementation caches CXF clients or ClientFactoryBean in CxfProvider and CxfRsProvider. This option allows you to configure the maximum size of the cache.
|
maxClientCacheSize=5
|
No | 10 |
setDefaultBus
|
New in 2.9.0. Will set the default bus when CXF endpoint create a bus by itself |
setDefaultBus=true
|
No |
false
|
bus
|
New in 2.9.0. A default bus created by CXF Bus Factory. Use \# notation to reference a bus object from the registry. The referenced object must be an instance of org.apache.cxf.Bus.
|
bus=#busName
|
No | _None_ |
You can also configure the CXF REST endpoint through the Spring configuration. Since there are lots of differences between the CXF REST client and CXF REST Server, we provide different configurations for them. Please check out the schema file and CXF REST user guide for more information.
How to configure the REST endpoint in Apache Camel
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 Apache Camel REST service route configuration example here.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:cxf="http://camel.apache.org/schema/cxf"
xmlns:jaxrs="http://cxf.apache.org/jaxrs"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://camel.apache.org/schema/cxf http://camel.apache.org/schema/cxf/camel-cxf.xsd
http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd
">
<!-- Defined the real JAXRS back end service -->
<jaxrs:server id="restService"
address="http://localhost:9002/rest"
staticSubresourceResolution="true">
<jaxrs:serviceBeans>
<ref bean="customerService"/>
</jaxrs:serviceBeans>
</jaxrs:server>
<!--bean id="jsonProvider" class="org.apache.cxf.jaxrs.provider.JSONProvider"/-->
<bean id="customerService" class="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService" />
<!-- Defined the server endpoint to create the cxf-rs consumer -->
<cxf:rsServer id="rsServer" address="http://localhost:9000/route"
serviceClass="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService"
loggingFeatureEnabled="true" loggingSizeLimit="20" skipFaultLogging="true"/>
<!-- Defined the client endpoint to create the cxf-rs consumer -->
<cxf:rsClient id="rsClient" address="http://localhost:9002/rest"
serviceClass="org.apache.camel.component.cxf.jaxrs.testbean.CustomerService"
loggingFeatureEnabled="true" skipFaultLogging="true"/>
<!-- The camel route context -->
<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="cxfrs://bean://rsServer"/>
<!-- We can remove this configure as the CXFRS producer is using the HttpAPI by default -->
<setHeader headerName="CamelCxfRsUsingHttpAPI">
<constant>True</constant>
</setHeader>
<to uri="cxfrs://bean://rsClient"/>
</route>
</camelContext>
</beans>How to consume the REST request in Apache Camel
CXF JAXRS front end implements the JAXRS(JSR311) 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, you don't need to specify the URI template within your restlet endpoint, CXF take care of the REST request URI to resource class method mapping according to the JSR311 specification. All you need to do in Apache 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";
protected RouteBuilder createRouteBuilder() throws Exception {
return new RouteBuilder() {
public void configure() {
errorHandler(new NoErrorHandlerBuilder());
from(CXF_RS_ENDPOINT_URI).process(new Processor() {
public void process(Exchange exchange) throws Exception {
Message inMessage = exchange.getIn();
// Get the operation name from in message
String operationName = inMessage.getHeader(CxfConstants.OPERATION_NAME, String.class);
if ("getCustomer".equals(operationName)) {
String httpMethod = inMessage.getHeader(Exchange.HTTP_METHOD, String.class);
assertEquals("Get a wrong http method", "GET", httpMethod);
String path = inMessage.getHeader(Exchange.HTTP_PATH, String.class);
// The parameter of the invocation is stored in the body of in message
String id = inMessage.getBody(String.class);
if ("/customerservice/customers/126".equals(path)) {
Customer customer = new Customer();
customer.setId(Long.parseLong(id));
customer.setName("Willem");
// We just put the response Object into the out message body
exchange.getOut().setBody(customer);
} else {
if ("/customerservice/customers/400".equals(path)) {
// We return the remote client IP address this time
org.apache.cxf.message.Message cxfMessage = inMessage.getHeader(CxfConstants.CAMEL_CXF_MESSAGE, org.apache.cxf.message.Message.class);
ServletRequest request = (ServletRequest) cxfMessage.get("HTTP.REQUEST");
String remoteAddress = request.getRemoteAddr();
Response r = Response.status(200).entity("The remoteAddress is " + remoteAddress).build();
exchange.getOut().setBody(r);
return;
}
if ("/customerservice/customers/123".equals(path)) {
// send a customer response back
Response r = Response.status(200).entity("customer response back!").build();
exchange.getOut().setBody(r);
return;
}
if ("/customerservice/customers/456".equals(path)) {
Response r = Response.status(404).entity("Can't found the customer with uri " + path).build();
throw new WebApplicationException(r);
} else {
throw new RuntimeCamelException("Can't found the customer with uri " + path);
}
}
}
if ("updateCustomer".equals(operationName)) {
assertEquals("Get a wrong customer message header", "header1;header2", inMessage.getHeader("test"));
String httpMethod = inMessage.getHeader(Exchange.HTTP_METHOD, String.class);
assertEquals("Get a wrong http method", "PUT", httpMethod);
Customer customer = inMessage.getBody(Customer.class);
assertNotNull("The customer should not be null.", customer);
// Now you can do what you want on the customer object
assertEquals("Get a wrong customer name.", "Mary", customer.getName());
// set the response back
exchange.getOut().setBody(Response.ok().build());
}
}
});
}
};
}
The corresponding resource class used to configure the endpoint is defined as an interface:
@Path("/customerservice/")
public interface CustomerServiceResource {
@GET
@Path("/customers/{id}/")
Customer getCustomer(@PathParam("id") String id);
@PUT
@Path("/customers/")
Response updateCustomer(Customer customer);
}
Important
The resource class is used to configure the JAXRS properties only. The methods will not be executed during the routing of messages to the endpoint, the route itself is responsible for all processing instead.
How to invoke the REST service through camel-cxfrs producer ?
CXF JAXRS front end implements a proxy based client API, with this API you can invoke the remote REST service through a proxy.
camel-cxfrs producer is based on this proxy API. So, you just need to specify the operation name in the message header and prepare the parameter in the message body, 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();
setupDestinationURL(inMessage);
// 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");
// 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 ", String.valueOf(response.getId()), "123");
assertEquals("Get a wrong customer name", response.getName(), "John");
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"));
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 Http method and let the the producer know to use the HTTP centric client by using the URI option httpClientAPI or set the message header with CxfConstants.CAMEL_CXF_RS_USING_HTTP_API. You can turn the response object to the type class that you specify with 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();
setupDestinationURL(inMessage);
// 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);
}
});
// get the response message
Customer response = (Customer) exchange.getOut().getBody();
assertNotNull("The response should not be null ", response);
assertEquals("Get a wrong customer id ", String.valueOf(response.getId()), "123");
assertEquals("Get a wrong customer name", response.getName(), "John");
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"));
From Apache 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:" + getPort2() + "/" + getClass().getSimpleName() + "/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<String, String>();
queryMap.put("q1", "new");
queryMap.put("q2", "world");
inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_QUERY_MAP, queryMap);