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Implement web services applications from existing WSDL files with JAX-WS

When starting with an existing Web Services Description Language (WSDL) file, we can use a top-down approach to developing web services based on JAX-WS.

IBM WebSphere Application Server supports JAX-WS and JAX-RPC. Using the strategic JAX-WS programming model, development of web services and clients is simplified through support of a standards-based annotations model. Although JAX-RPC and applications are still supported, take advantage of the easy-to-implement JAX-WS programming model to develop new web services applications and clients.best-practices

Locate the WSDL file that defines the web service to implement. We can develop a WSDL file or obtain one from an existing web service through email, downloading or a URL.

To develop web services based on JAX-WS, we can use a bottom-up development approach starting from existing JavaBeans or enterprise beans or we can use a top-down development approach starting with an existing WSDL file. This task describes the steps when using the top-down development approach.

Considerations when using JavaBeans

  • JavaBeans exposed as JAX-WS web services are supported only over an HTTP transport.
  • JavaBeans may use Contexts and Dependency Injection (CDI). Note that constructor injection is not supported.

Considerations when using enterprise beans

  • The enterprise bean must be a stateless or singleton session bean.

  • Enterprise beans exposed as JAX-WS web services must be packaged in EJB 3.0 or higher modules.
  • JAX-WS web service applications containing enterprise beans must be deployed with the endptEnabler command.
  • JAX-WS web services using enterprise beans are supported over an HTTP or JMS transport.

  • Enterprise beans may use CDI. Note that constructor injection is not supported.


Tasks

  1. Set up a development environment for web services. We do not have to set up a development environment if we are using Rational Application Developer.
  2. Develop Java artifacts for JAX-WS applications using the wsimport command-line tool. The wsimport tool processes a WSDL file and generates portable Java artifacts used to create a web service.
  3. (optional) Enable MTOM for JAX-WS web services. Use SOAP Message Transmission Optimization Mechanism to optimize the transmission of binary attachments such as images or files along with web services requests.
  4. (optional) Enforce adherence to WSDL bindings in JAX-WS web services. Use the RespectBindingFeature to control whether a JAX-WS implementation is required to respect the contents of a wsdl:binding associated with an endpoint.
  5. (optional) Develop and configure a webservices.xml deployment descriptor for JAX-WS applications. We can optionally use the webservices.xml deployment descriptor to augment or override application metadata specified in annotations within the JAX-WS web services.
  6. Complete the implementation of our web service application.

  7. (Optional) Customize URL patterns in the web.xml file. When JavaBeans are exposed as JAX-WS endpoints, we can optionally customize the URL patterns within the web.xml deployment descriptor contained in the web application archive (WAR) file.
  8. Assemble the artifacts for our web service.
  9. Deploy the EAR file into the application server. We can now deploy the EAR file configured and enabled for web services onto the application server.
  10. Test the web service to make sure that the service works with the application server.

We have created a JAX-WS web service by starting with an existing WSDL file.


Related:

  • JAX-WS
  • Set up a development environment for web services
  • Generate Java artifacts for JAX-WS applications from a WSDL file
  • Enable MTOM for JAX-WS web services
  • Enforcing adherence to WSDL bindings in JAX-WS web services
  • Developing a webservices.xml deployment descriptor for JAX-WS applications
  • Completing the JavaBeans implementation for JAX-WS applications
  • Completing the EJB implementation for JAX-WS applications
  • Customize URL patterns in the web.xml file for JAX-WS applications
  • Assembling web services applications
  • Deploy web services applications onto application servers
  • Testing web services-enabled clients
  • Use HTTP to transport web services
  • Use SOAP over JMS to transport web services
  • Example: Installing a web services sample with the console
  • Implement web services applications with JAX-WS
  • Artifacts used to develop web services
  • Web services specifications and APIs
  • Contexts and Dependency Injection (CDI)
  • JAX-WS API documentation
  • JAX-WS API User's Guide documentation