What's the Camel Transport for CXF

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 You can use the camel-cxf component to communicate the CXF endpoints in Camel Context, in this way we just treat CXF as a service framework library in Camel. But if you want to leverage the Camel routing and mediation engine in CXF , the best way is to treat Camel as an EIP library and put it into CXF transport layer. The Camel transport for CXF is this kind of component which implements the CXF transport API with the Camel core library.

CXF architecture in one minute

CXF is a service framework which supports lots of transports and bindings and you can easily develop and publish the service as you want. Here are two layers in the CXF runtime, one is generic messaging layer comprised of Messages, Interceptors, and InterceptorChains, the other is transport layer which hides transport specific details from the messaging layer. This two layer are build up with the service model which holds the WS* meta data. The transport layer with feed the incoming message to the message layer and consume the outgoing message from the message layer.

You can find the more information for the CXF architecture document herehttp://cwiki.apache.org/CXF20DOC/cxf-architecture.html.

Integrate Camel's into CXF transport layer

Camel transport for CXF implements the CXF transport API, you could treat it as a normal transport implementation. But you need to initiate a camel context for the camel transport and do the routing and mediation work as you want in the CXF transport layer than pass the message to CXF Messaging layer for the WS* message handling.
Here we connect a camel consumer with the Camel conduit and a camel producer with the Camel Destination by using the endpoint URL in a certain Camel context.

Configure the Camel context

Basically , Camel transport factory is in charge of Camel transport, and CXF core will load this factory when you put the camel-cxf.jar into the class path. Since you need to pass the camel context into the transport layer , you could do it in a programmatic way or with the spring configuration.

This allows you to easily use Camel's routing engine and integration patterns support together with your CXF services.

Integrate Camel into CXF transport layer

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

Setting up the Camel Transport in Spring

You can use the following snippet in your applicationcontext if you want to configure anything special. If you only want to activate the camel transport you do not have to do anything in your application context. As soon as you include the camel-cxf-transport jar (or camel-cxf.jar if your camel version is less than 2.7.x) in your app, cxf will scan the jar and load a CamelTransportFactory for you.

...

Integrating the Camel Transport

...

in a programmatic way

Camel transport provides a setConetxt setContext method that you could use to set the Camel context into the transport factory. If you want this factory take effect, you need to register the factory into the CXF bus. Here is a full example for you.

...

...

Configure the destination and conduit with Spring

Namespace

The elements used to configure an Camel transport endpoint are defined in the namespace http://cxf.apache.org/transports/camel. It is commonly referred to using the prefix camel. In order to use the Camel transport configuration elements, you will need to add the lines shown below to the beans element of your endpoint's configuration file. In addition, you will need to add the configuration elements' namespace to the xsi:schemaLocation attribute.

...

The destination element

You configure an Camel transport server endpoint using the camel:destination element and its children. The camel:destination element takes a single attribute, name, that specifies the WSDL port element that corresponds to the endpoint. The value for the name attribute takes the form portQName.camel-destination. The example below shows the camel:destination element that would be used to add configuration for an endpoint that was specified by the WSDL fragment <port binding="widgetSOAPBinding" name="widgetSOAPPort"> if the endpoint's target namespace was http://widgets.widgetvendor.net.

...

The camel:destination element for Spring has a number of child elements that specify configuration information. They are described below.

The conduit element

You configure a Camel transport client using the camel:conduit element and its children. The camel:conduit element takes a single attribute, name, that specifies the WSDL port element that corresponds to the endpoint. The value for the name attribute takes the form portQName.camel-conduit. For example, the code below shows the camel:conduit element that would be used to add configuration for an endpoint that was specified by the WSDL fragment <port binding="widgetSOAPBinding" name="widgetSOAPPort"> if the endpoint's target namespace was http://widgets.widgetvendor.net.

...

The camel:conduit element has a number of child elements that specify configuration information. They are described below.

Configure the destination and conduit with Blueprint

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

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

...

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

...

Example Using Camel as a load balancer for CXF

This example shows how to use the camel load balancing feature in CXF. You need to

Setting the Camel context with the spring configuration

Since Camel and CXF both support the spring configuration, you can easily set up the Camel context in the Camel transport for CXF. If you do not familiar with the CXF transport configuration, please ref to http://cwiki.apache.org/CXF20DOC/server-http-transport.html and http://cwiki.apache.org/CXF20DOC/client-http-transport-including-ssl-support.html for more information.
This example show how to use the camel load balance feature in CXF, and you need load the configuration file in CXF and publish the endpoints on the address "camel://direct:EndpointA" and "camel://direct:EndpointB"

...

...

If you just want to set the conduit's Camel context, you can take the below configuration file as an example

Complete Howto and Example for attaching Camel to CXF

Better JMS Transport for CXF Webservice using Apache Camel 

...