This example will lead you through creating your first service with Spring. You'll learn how to:
- Set up your build for CXF
- Writing a simple JAX-WS service
- Set up the HTTP transport
This example corresponds to the spring_http example in the CXF distribution.
Setting up your build
Open up your favorite IDE and create a new project. The first thing we need to do is add the necessary CXF dependencies to the project. You can find these dependencies in the CXF distribution in the lib directory.
commons-logging-1.1.jar geronimo-activation_1.1_spec-1.0-M1.jar (or Sun's Activation jar) geronimo-annotation_1.0_spec-1.1.jar (JSR 250) geronimo-javamail_1.4_spec-1.0-M1.jar (or Sun's JavaMail jar) geronimo-servlet_2.5_spec-1.1-M1.jar (or Sun's Servlet jar) geronimo-ws-metadata_2.0_spec-1.1.1.jar (JSR 181) jaxb-api-2.0.jar jaxb-impl-2.0.5.jar jaxws-api-2.0.jar neethi-2.0.jar saaj-api-1.3.jar saaj-impl-1.3.jar stax-api-1.0.1.jar wsdl4j-1.6.1.jar wstx-asl-3.2.1.jar XmlSchema-1.2.jar xml-resolver-1.2.jar
The Spring jars:
aopalliance-1.0.jar spring-core-2.0.4.jar spring-beans-2.0.4.jar spring-context-2.0.4.jar spring-web-2.0.4.jar
And the CXF jar:
cxf-2.0-incubator.jar
Writing your Service
First we'll write our service interface. It will have one operation called "sayHello" which says "Hello" to whoever submits their name.
Our implementation will then look like this:
The @WebService
annotation on the implementation class lets CXF know which interface to use when creating WSDL. In this case its simply our HelloWorld interface.
Declaring your server beans
CXF contains support for "nice XML" within Spring 2.0. For the JAX-WS side of things, we have a <jaxws:endpoint> bean which sets up a server side endpoint.
Lets create a "beans.xml" file in our WEB-INF directory which declares an endpoint bean:
The bean uses the following properties:
id
specifies the id of the bean in the Spring context.implementor
specifies the implementation class.address
specifies the location the service will be hosted. This should just be a related path. This is because CXF can't know the war name and the servlet container's listening port, CXF will update the endpoint address with the request url at the runtime.
To provide a bean name instead of a classname as an implementor, simply supply the bean-name prepended with "#", e.g. implementor="#myBean".
Setting up the Servlet
We'll need to add two things to our web.xml file:
- the Spring
ContextLoaderLister
. This starts Spring and loads our beans.xml file. We can specify where our file is via acontext-param
element. - the CXF Servlet
Error formatting macro: snippet: java.lang.NullPointerException
It is important to note that the address that you chose for your endpoint bean must be one your servlet listens on. For instance, if my Servlet was register for "/some-services/*" but my address was "/more-services/HelloWorld", there is no way CXF could receive a request.
Create a Client
CXF includes a JaxWsProxyFactory bean which create a client for you from your service interface. You simply need to tell it what your service class is (the HelloWorld interface in this case) and the URL of your service. You can then create a client bean via the JaxWsProxyFactory bean by calling it's create() method.
Here's an example:
If you were going to access your client you could now simply pull it out of the Spring context (or better yet, inject it into your application using Spring!):
ApplicationContext context = ...; // your Spring ApplicationContext HellWorld client = (HelloWorld) context.getBean("client");
Advanced Steps
For more information on using Spring you may want to read the Configuration and Spring sections of the User's Guide.