Network Deployment (Distributed operating systems), v8.0 > End-to-end paths > Web services
Implementing web services applications with JAX-WS
When starting from existing JavaBeans or enterprise beans, you can use a bottom-up approach to developing Web services based on JAX-WS.
Best practice: IBM WAS supports the JAX-WS
programming model and JAX-RPC. JAX-WS is the next generation web services programming model extending the foundation provided by 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.
bprac
JAX-WS
To develop web services based on JAX-WS, you can use a bottom-up development approach starting from existing JavaBeans or enterprise beans or you can use a top-down development approach starting with an existing WSDL file. This task describes the steps when using the bottom-up development approach.
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, 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.
- 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.
- 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 JMS transport.
- Enterprise beans may use CDI. Note that constructor injection is not supported.
For transitioning users: Starting with WAS v7.0 and later, Java EE 5 application modules (web application modules version 2.5 or above, or EJB modules version 3.0 or above)
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 v6.1 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 WAS 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, configure either the UseWSFEP61ScanPolicy property in the META-INF/MANIFEST.MF of a 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. trns
Procedure
- Set up a development environment for web services.
- Determine the existing JavaBeans or enterprise beans to expose as a JAX-WS web service.
- Develop JAX-WS web services with annotations.
- Generate Java artifacts for JAX-WS applications.
- (optional) Enable MTOM for JAX-WS web services.
- (optional) Enforce adherence to WSDL bindings in JAX-WS web services.
- (optional) Develop and configure a webservices.xml deployment descriptor for JAX-WS applications.
- Complete the implementation of your web services application.
- (Optional) Customize URL patterns in the web.xml file.
- Assemble the artifacts for your web service.
- Deploy the EAR file into the application server.
- Test the web service to make sure that the service works with the application server.
Results
You have developed a JAX-WS application.