CXF-RS

Since Camel 2.0

Both producer and consumer are supported

The CXFRS component provides integration with Apache CXF for connecting to JAX-RS 1.1 and 2.0 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>

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 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

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The CXF-RS component supports 5 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

headerFilterStrategy (filter)

To use a custom org.apache.camel.spi.HeaderFilterStrategy to filter header to and from Camel message.

HeaderFilterStrategy

useGlobalSslContextParameters (security)

Enable usage of global SSL context parameters.

false

boolean

Endpoint Options

The CXF-RS endpoint is configured using URI syntax:

cxfrs:beanId:address

with the following path and query parameters:

Path Parameters (2 parameters)

Name Description Default Type

beanId (common)

To lookup an existing configured CxfRsEndpoint. Must used bean: as prefix.

String

address (common)

The service publish address.

String

Query Parameters (31 parameters)

Name Description Default Type

features (common)

Set the feature list to the CxfRs endpoint.

List

loggingFeatureEnabled (common)

This option enables CXF Logging Feature which writes inbound and outbound REST messages to log.

false

boolean

loggingSizeLimit (common)

To limit the total size of number of bytes the logger will output when logging feature has been enabled.

int

modelRef (common)

This option is used to specify the model file which is useful for the resource class without annotation. When using this option, then the service class can be omitted, to emulate document-only endpoints.

String

providers (common)

Set custom JAX-RS provider(s) list to the CxfRs endpoint. You can specify a string with a list of providers to lookup in the registy separated by comma.

String

resourceClasses (common)

The resource classes which you want to export as REST service. Multiple classes can be separated by comma.

List

schemaLocations (common)

Sets the locations of the schema(s) which can be used to validate the incoming XML or JAXB-driven JSON.

List

skipFaultLogging (common)

This option controls whether the PhaseInterceptorChain skips logging the Fault that it catches.

false

boolean

bindingStyle (consumer)

Sets how requests and responses will be mapped to/from Camel. Two values are possible: SimpleConsumer: This binding style processes request parameters, multiparts, etc. and maps them to IN headers, IN attachments and to the message body. It aims to eliminate low-level processing of org.apache.cxf.message.MessageContentsList. It also also adds more flexibility and simplicity to the response mapping. Only available for consumers. Default: The default style. For consumers this passes on a MessageContentsList to the route, requiring low-level processing in the route. This is the traditional binding style, which simply dumps the org.apache.cxf.message.MessageContentsList coming in from the CXF stack onto the IN message body. The user is then responsible for processing it according to the contract defined by the JAX-RS method signature. Custom: allows you to specify a custom binding through the binding option.

Enum values:

  • SimpleConsumer

  • Default

  • Custom

Default

BindingStyle

publishedEndpointUrl (consumer)

This option can override the endpointUrl that published from the WADL which can be accessed with resource address url plus _wadl.

String

bridgeErrorHandler (consumer (advanced))

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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

exceptionHandler (consumer (advanced))

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 (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

ExchangePattern

serviceBeans (consumer (advanced))

The service beans (the bean ids to lookup in the registry) which you want to export as REST service. Multiple beans can be separated by comma.

String

cookieHandler (producer)

Configure a cookie handler to maintain a HTTP session.

CookieHandler

hostnameVerifier (producer)

The hostname verifier to be used. Use the # notation to reference a HostnameVerifier from the registry.

HostnameVerifier

sslContextParameters (producer)

The Camel SSL setting reference. Use the # notation to reference the SSL Context.

SSLContextParameters

throwExceptionOnFailure (producer)

This option tells the CxfRsProducer to inspect return codes and will generate an Exception if the return code is larger than 207.

true

boolean

httpClientAPI (producer (advanced))

If it is true, the CxfRsProducer will use the HttpClientAPI to invoke the service. If it is false, the CxfRsProducer will use the ProxyClientAPI to invoke the service.

true

boolean

ignoreDeleteMethodMessageBody (producer (advanced))

This option is used to tell CxfRsProducer to ignore the message body of the DELETE method when using HTTP API.

false

boolean

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

maxClientCacheSize (producer (advanced))

This option allows you to configure the maximum size of the cache. The implementation caches CXF clients or ClientFactoryBean in CxfProvider and CxfRsProvider.

10

int

synchronous (producer (advanced))

Sets whether synchronous processing should be strictly used.

false

boolean

binding (advanced)

To use a custom CxfBinding to control the binding between Camel Message and CXF Message.

CxfRsBinding

bus (advanced)

To use a custom configured CXF Bus.

Bus

continuationTimeout (advanced)

This option is used to set the CXF continuation timeout which could be used in CxfConsumer by default when the CXF server is using Jetty or Servlet transport.

30000

long

cxfRsConfigurer (advanced)

This option could apply the implementation of org.apache.camel.component.cxf.jaxrs.CxfRsEndpointConfigurer which supports to configure the CXF endpoint in programmatic way. User can configure the CXF server and client by implementing configure\{Server/Client} method of CxfEndpointConfigurer.

CxfRsConfigurer

defaultBus (advanced)

Will set the default bus when CXF endpoint create a bus by itself.

false

boolean

headerFilterStrategy (advanced)

To use a custom HeaderFilterStrategy to filter header to and from Camel message.

HeaderFilterStrategy

performInvocation (advanced)

When the option is true, Camel will perform the invocation of the resource class instance and put the response object into the exchange for further processing.

false

boolean

propagateContexts (advanced)

When the option is true, JAXRS UriInfo, HttpHeaders, Request and SecurityContext contexts will be available to custom CXFRS processors as typed Camel exchange properties. These contexts can be used to analyze the current requests using JAX-RS API.

false

boolean

Message Headers

The CXF-RS component supports 16 message header(s), which is/are listed below:

Name Description Default Type

operationName (common)

Constant: OPERATION_NAME

The name of the operation.

String

CamelAuthentication (common)

Constant: AUTHENTICATION

The authentication.

Subject

CamelHttpMethod (common)

Constant: HTTP_METHOD

The http method to use.

String

CamelHttpPath (common)

Constant: HTTP_PATH

The http path.

String

Content-Type (common)

Constant: CONTENT_TYPE

The content type.

String

CamelHttpQuery (common)

Constant: HTTP_QUERY

The http query.

String

CamelHttpResponseCode (common)

Constant: HTTP_RESPONSE_CODE

The http response code.

Integer

Content-Encoding (common)

Constant: CONTENT_ENCODING

The content encoding.

String

org.apache.cxf.message.Message.PROTOCOL_HEADERS (common)

Constant: PROTOCOL_HEADERS

The protocol headers.

Map

CamelCxfMessage (common)

Constant: CAMEL_CXF_MESSAGE

The CXF message.

Message

CamelCxfRsUsingHttpAPI (common)

Constant: CAMEL_CXF_RS_USING_HTTP_API

If it is true, the CxfRsProducer will use the HttpClientAPI to invoke the service. If it is false, the CxfRsProducer will use the ProxyClientAPI to invoke the service.

Boolean

CamelCxfRsVarValues (common)

Constant: CAMEL_CXF_RS_VAR_VALUES

The path values.

Object[]

CamelCxfRsResponseClass (common)

Constant: CAMEL_CXF_RS_RESPONSE_CLASS

The response class.

Class

CamelCxfRsResponseGenericType (common)

Constant: CAMEL_CXF_RS_RESPONSE_GENERIC_TYPE

The response generic type.

Type

CamelCxfRsQueryMap (common)

Constant: CAMEL_CXF_RS_QUERY_MAP

The query map.

Map

CamelCxfRsOperationResourceInfoStack (common)

Constant: CAMEL_CXF_RS_OPERATION_RESOURCE_INFO_STACK

The stack of MethodInvocationInfo representing resources path when JAX-RS invocation looks for target.

OperationResourceInfoStack

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.

How to configure the REST endpoint in 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 Camel REST service route configuration example here.

How to override the CXF producer address from message header

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()));

Consuming a REST Request - Simple Binding Style

Since 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:

  • JAX-RS Parameters (@HeaderParam, @QueryParam, etc.) are injected as IN message headers. The header name matches the value of the annotation.

  • The request entity (POJO or other type) becomes the IN message body. If a single entity cannot be identified in the JAX-RS method signature, it falls back to the original MessageContentsList.

  • Binary @Multipart body parts become IN message attachments, supporting DataHandler, InputStream, DataSource and CXF’s Attachment class.

  • Non-binary @Multipart body parts are mapped as IN message headers. The header name matches the Body Part name.

Additionally, the following rules apply to the Response mapping:

  • If the message body type is different to javax.ws.rs.core.Response (user-built response), a new Response is created and the message body is set as the entity (so long it’s not null). The response status code is taken from the Exchange.HTTP_RESPONSE_CODE header, or defaults to 200 OK if not present.

  • If the message body type is equal to javax.ws.rs.core.Response, it means that the user has built a custom response, and therefore it is respected and it becomes the final response.

  • In all cases, Camel headers permitted by custom or default HeaderFilterStrategy are added to the HTTP response.

Enabling the Simple Binding Style

This binding style can be activated by setting the bindingStyle parameter in the consumer endpoint to value SimpleConsumer:

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

Examples of request binding with different method signatures

Below is a list of method signatures along with the expected result from the Simple binding.

public Response doAction(BusinessObject request);
Request payload is placed in IN message body, replacing the original MessageContentsList.

public Response doAction(BusinessObject request, @HeaderParam("abcd") String abcd, @QueryParam("defg") String defg); Request payload placed in IN message body, replacing the original MessageContentsList. Both request params mapped as IN message headers with names abcd and defg.

public Response doAction(@HeaderParam("abcd") String abcd, @QueryParam("defg") String defg); Both request params mapped as IN message headers with names abcd and defg. The original MessageContentsList is preserved, even though it only contains the 2 parameters.

public Response doAction(@Multipart(value="body1") BusinessObject request, @Multipart(value="body2") BusinessObject request2); The first parameter is transferred as a header with name body1, and the second one is mapped as header body2. The original MessageContentsList is preserved as the IN message body.

public Response doAction(InputStream abcd); The InputStream is unwrapped from the MessageContentsList and preserved as the IN message body.

public Response doAction(DataHandler abcd); The DataHandler is unwrapped from the MessageContentsList and preserved as the IN message body.

More examples of the Simple Binding Style

Given a JAX-RS resource class with this method:

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

Serviced by the following route:

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

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

The following HTTP request with XML payload (given that the Customer DTO is JAXB-annotated):

POST /customers/gold?active=true

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

Will print the message:

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

For more examples on how to process requests and write responses can be found here.

Consuming a REST Request - Default Binding Style

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. 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…​

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.

It is sufficient to provide an interface only as opposed to a no-op service implementation class for the default mode.

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);
}

How to invoke the REST service through camel-cxfrs producer

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.getMessage().getBody();

assertNotNull(response, "The response should not be null");
assertEquals(123, response.getId(), "Get a wrong customer id");
assertEquals("John", response.getName(), "Get a wrong customer name");
assertEquals(200, exchange.getMessage().getHeader(Exchange.HTTP_RESPONSE_CODE), "Get a wrong response code");
assertEquals("value", exchange.getMessage().getHeader("key"), "Get a wrong header value");

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);
    }
});

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);