Example: Developing and deploying a JAX-RPC Web service from an existing application

We can develop a JAX-RPC Web service from an EJB or Java Beans implementation. The development process is based on the Web Services for Java EE specification.

1. Select the enterprise bean or Java Beans implementation that you want to enable as a JAX-RPC Web service.The implementation must meet the following Web Services for Java EE spec requirements:

   • It must have methods that can be mapped to a service endpoint interface. See step 2 for more information.

   • It must be a stateless session EJB implementation or a Java Beans implementation without client-specific state, because the implementation bean might be selected to process a request from any client. If a client-specific state is required, a client identifier must be passed as a parameter of the Web services operation.

     The selected methods of an enterprise bean must not have a transaction attribute of mandatory, because no standard currently exists, for these Web services transactions. A Java Beans implementation in a Web container requires the following contents:

     • A public default constructor

     • Exposed public methods

     • It must not save a client-specific state between method calls

     • It must be a public, non-final, and non-abstract class

     • It must not define a finalize method

2. Develop a service endpoint interface.

   Develop a Web service requires a service endpoint interface.

   For an EJB implementation, develop a service endpoint interface from an EJB remote interface.

   For a Java Beans implementation, develop a service endpoint interface for a Java Beans implementation.

3. Develop a Web Services Description Language (WSDL) file.

4. Develop deployment descriptor templates.

   For an EJB implementation, develop Web services deployment descriptor templates from an EJB implementation.

   If we are using a Java Beans implementation, develop Web services deployment descriptor templates for a Java Beans implementation.

5. Set the deployment descriptors.

   By setting the ejb-link or servlet-link values of the service-impl-bean elements we can link to the enterprise bean or Java Beans implementation that implement the service.

   Configure the webservices.xml deployment descriptor.

   Set the ibm-webservices-bnd.xmi deployment descriptor.

6. Assemble an enterprise archive (EAR) file from a JAR file or assemble an EAR file from a WAR file.
7. Enable the Web service-enabled EAR file.

   This step only applies if we are using an EJB implementation.

8. Deploy the Web service application.
9. Publish the WSDL file.

For a complete list of the supported standards and specifications, see the Web services specifications and API documentation.

---

 

Related tasks

Implement Web services applications with JAX-RPC

 

Related

Web services specifications and APIs