= CXF-RS Component
:doctitle: CXF-RS
:shortname: cxfrs
:artifactid: camel-cxf-rest
:description: Expose JAX-RS REST services using Apache CXF or connect to external REST services using CXF REST client.
:since: 2.0
:supportlevel: Stable
:component-header: Both producer and consumer are supported
//Manually maintained attributes
:camel-spring-boot-name: cxf-rest

*Since Camel {since}*

*{component-header}*

The CXFRS component provides integration with
http://cxf.apache.org[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:

[source,xml]
-------------------------------------------------------------------------------------
<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
------------------------------------------------------------------


// component-configure options: START

// component-configure options: END

// component options: START
include::partial$component-configure-options.adoc[]
include::partial$component-endpoint-options.adoc[]
// component options: END

// endpoint options: START

// endpoint options: END

// component headers: START
include::partial$component-endpoint-headers.adoc[]
// component headers: END

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
https://github.com/apache/camel/blob/main/components/camel-cxf/camel-cxf-spring-rest/src/main/resources/schema/cxfJaxrsEndpoint.xsd[schema
file] and http://cxf.apache.org/docs/jax-rs.html[CXF JAX-RS
documentation] for more information.

== How to configure the REST endpoint in Camel

In
https://github.com/apache/camel/blob/main/components/camel-cxf/camel-cxf-spring-rest/src/main/resources/schema/cxfJaxrsEndpoint.xsd[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".

[source,java]
----------------------------------------------------------------------------------------------
 // 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`:

[source,java]
---------------------------------------------------------
  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:

[source,java]
------------------------------------------------------------------------------------------------------------------------------------------------
@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:

[source,java]
--------------------------------------------------------------------------------------------
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
https://svn.apache.org/repos/asf/camel/trunk/components/camel-cxf/src/test/java/org/apache/camel/component/cxf/jaxrs/simplebinding/[here].

== Consuming a REST Request - Default Binding Style

The http://cxf.apache.org/docs/jax-rs.html[CXF JAXRS front end]
implements the https://javaee.github.io/jsr311/[JAX-RS (JSR-311) API], so we can
export the resources classes as a REST service. And we leverage the
http://cxf.apache.org/docs/invokers.html[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...
[source,java]
----
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]
====
*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.

[source,java]
----
@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 http://cxf.apache.org/docs/jax-rs.html[CXF JAXRS front end]
implements
http://cxf.apache.org/docs/jax-rs-client-api.html#JAX-RSClientAPI-Proxy-basedAPI[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
http://cxf.apache.org/docs/jax-rs-client-api.html#JAX-RSClientAPI-Proxy-basedAPI[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:
[source,java]
----
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(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.getOut().getHeader(Exchange.HTTP_RESPONSE_CODE), "Get a wrong response code");
assertEquals("value", exchange.getOut().getHeader("key"), "Get a wrong header value");
----

The http://cxf.apache.org/docs/jax-rs.html[CXF JAXRS front end] also
provides
http://cxf.apache.org/docs/jax-rs-client-api.html#JAX-RSClientAPI-CXFWebClientAPI[a
http centric client API]. You can also invoke this API from
`camel-cxfrs` producer. You need to specify the
https://www.javadoc.io/doc/org.apache.camel/camel-api/current/org/apache/camel/Exchange.html#HTTP_PATH[HTTP_PATH]
and
the https://www.javadoc.io/doc/org.apache.camel/camel-api/current/org/apache/camel/Exchange.html#HTTP_METHOD[HTTP_METHOD] and
let the producer use the http centric client API by using the URI option
*httpClientAPI* or by setting the message header
https://www.javadoc.io/doc/org.apache.camel/camel-cxf-transport/current/org/apache/camel/component/cxf/common/message/CxfConstants.html#CAMEL_CXF_RS_USING_HTTP_API[CxfConstants.CAMEL_CXF_RS_USING_HTTP_API].
You can turn the response object to the type class specified with the
message
header https://www.javadoc.io/doc/org.apache.camel/camel-cxf-transport/current/org/apache/camel/component/cxf/common/message/CxfConstants.html#CAMEL_CXF_RS_RESPONSE_CLASS[CxfConstants.CAMEL_CXF_RS_RESPONSE_CLASS].
[source,java]
----
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.
[source,java]
----
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 https://www.javadoc.io/doc/org.apache.camel/camel-cxf-transport/current/org/apache/camel/component/cxf/common/message/CxfConstants.html#CAMEL_CXF_RS_QUERY_MAP[CxfConstants.CAMEL_CXF_RS_QUERY_MAP]
header to set the parameter map for it.
[source,java]
----
Map<String, String> queryMap = new LinkedHashMap<>();
queryMap.put("q1", "new");
queryMap.put("q2", "world");
inMessage.setHeader(CxfConstants.CAMEL_CXF_RS_QUERY_MAP, queryMap);
----


include::spring-boot:partial$starter.adoc[]
