Example: Developing Web services based on Web Services for J2EE
This example takes you through the steps to develop a Web service from an enterprise JavaBean (EJB) implementation. The development process is based on the Web Services for J2EE specification.
- Select the EJB or Java bean implementation that you want to enable as a Web service.
The implementation must meet the following Web Services for J2EE specification 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 or a Java bean without client-specific state, since 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 service operation.
The selected methods of an EJB must not have a transaction attribute of Mandatory, because there is no standard for Web services transactions at this time.
A Java bean in a Web container requires the following...
- 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
- Develop a Service Endpoint Interface.
Developing a Web service requires a Service Endpoint Interface.
If you are using an EJB implementation, develop a Service Endpoint Interface from an EJB remote interface.
If you are using a Java bean implementation, develop a Service Endpoint Interface for a Java bean implementation.
- Develop a WSDL file.
- Develop deployment descriptor templates.
If you are using an EJB implementation, develop Web services deployment descriptor templates from an EJB implementation.
If you are using a Java bean implementation, develop Web services deployment descriptor templates for a Java bean implementation.
- Configure the deployment descriptors.
By setting the ejb-link or servlet-link values of the service-impl-bean elements you can link to the EJB or Java bean that implements the service.
Configure the webservices.xml deployment descriptor.
Configure the ibm-webservices-bnd.xmi deployment descriptor.
- Assemble a JAR file or Assemble a WAR file.
- Assemble an EAR file from a Jar file or Assemble an EAR file from a WAR file.
- Enable the Web service-enabled EAR file.
This step only applies if you are using an EJB implementation.
- Deploy the Web service application.
- Publish the WSDL file.
See AlsoDeveloping Web services based on Web Services for J2EE