Developing JAX-WS web services (bottom-up)

When starting from existing JavaBeans or enterprise beans, you can use a bottom-up approach to developing Web services based on the Java™ API for XML-Based Web Services (JAX-WS) programming model.

Before you begin

Determine the existing JavaBeans or enterprise beans that you want to expose as a JAX-WS web service.

Best practice: During the JAX-WS provider implementation, do not dispatch the incoming requests to other processors like servlet, JSP, JAX-RS, or other JAX-WS service. If you dispatch the requests to other processors, it breaks the normal flow of the JAX-WS engine, so the JAX-WS engine does not support this situation.

About this task

When developing JAX-WS web services starting from existing JavaBeans or enterprise beans, you can expose the bean as a JAX-WS web service by using annotations. Adding the @WebService or @WebServiceProvider annotation to the bean defines the bean as a JAX-WS web service. JAX-WS web services can optionally use a service endpoint interface. In addition to annotating the bean and the optional service endpoint interface, you must assemble all the artifacts that the web service requires, and deploy the resulting application into the application server environment to complete the process of enabling the bean as a web service. Although the use of a WSDL file is considered a best practice, you are not required to package a WSDL file with your JAX-WS web services.

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 that are exposed as JAX-WS web services must be packaged in EJB 3.0 or higher modules.
  • JAX-WS applications containing enterprise beans must be deployed with the endptEnabler command.
  • JAX-WS web services using enterprise beans are supported over an HTTP or Java Message Service (JMS) transport.
  • Enterprise beans may use CDI. Note that constructor injection is not supported.
  • You can optionally include Web Services Description Language (WSDL) documents in the JAX-WS application packaging.

Starting with WebSphere® Application Server Version 7.0 and later, Java EE 5 application modules (web application modules version 2.5 or later, or EJB modules version 3.0 or later) are scanned for annotations to identify JAX-WS services and clients. However, pre-Java EE 5 application modules (web application modules version 2.4 or before, or EJB modules version 2.1 or before) are not scanned for JAX-WS annotations, by default, for performance considerations. In the Version 6.1 Feature Pack for Web Services, the default behavior is to scan pre-Java EE 5 web application modules to identify JAX-WS services and to scan pre-Java EE 5 web application modules and EJB modules for service clients during application installation. Because the default behavior for WebSphere Application Server Version 7.0 and later is to not scan pre-Java EE 5 modules for annotations during application installation or server startup, to preserve backward compatability with the feature pack from previous releases, you must configure either the UseWSFEP61ScanPolicy property in the META-INF/MANIFEST.MF of a web application archive (WAR) file or EJB module or define the Java virtual machine custom property, com.ibm.websphere.webservices.UseWSFEP61ScanPolicy, on servers to request scanning during application installation and server startup. To learn more about annotations scanning, see the JAX-WS annotations information.

Procedure

  1. Set up a development environment for web services.
    You do not have to set up a development environment if you are using Rational® Application Developer.
  2. Determine the existing JavaBeans or enterprise beans that you want to expose as a JAX-WS web service.
  3. Develop JAX-WS web services with annotations.
  4. Generate Java artifacts for JAX-WS applications.

    Use JAX-WS tooling to generate the necessary JAX-WS and JAXB artifacts needed for JAX-WS web services applications when starting from JavaBeans or enterprise beans components.

    If you are developing a service implementation bean that is invoked using the HTTP transport, then the WSDL file generated by the wsgen command-line tool during this step is optional. However, if you are developing a service implementation bean that is invoked using the SOAP over JMS transport, then the WSDL file generated by the wsgen tool during this step is required in subsequent steps, and therefore, not optional.

  5. (optional) Enable MTOM for JAX-WS web services.
    You can use SOAP Message Transmission Optimization Mechanism (MTOM) to optimize the transmission of binary attachments, such as images or files along with web services requests.
  6. (optional) Enforce adherence to WSDL bindings in JAX-WS web services.
    You can use the RespectBindingFeature to control whether a JAX-WS implementation is required to respect the contents of a wsdl:binding that is associated with an endpoint.
  7. (optional) Develop and configure a webservices.xml deployment descriptor for JAX-WS applications.
    You can optionally use the webservices.xml deployment descriptor to augment or override application metadata that is specified in annotations within your JAX-WS web services.
  8. Complete the implementation of your web services application.
  9. (Optional) Customize URL patterns in the web.xml file.
    When JavaBeans are exposed as JAX-WS endpoints, you can optionally customize the URL patterns within the web.xml deployment descriptor contained in the web application archive (WAR) file.
  10. Assemble the artifacts for your web service.

    Use assembly tools provided with the application server to assemble your Java-based web services modules.

    If you have assembled an EAR file that contains enterprise beans modules that include web services, use the endptEnabler command-line tool or an assembly tool before deployment to produce a web services endpoint WAR file. This tool is also used to specify whether the web services are exposed using SOAP over Java Message Service (JMS) or SOAP over HTTP.

  11. Deploy the EAR file into the application server.
    You can now deploy the EAR file that has been configured and enabled for JAX-WS web services onto the application server.
  12. Test the web service to make sure that the service works with the application server.

Results

You have developed a JAX-WS application.