Writing Java class based Web Services involves building a Java class that includes one or more methods. When a Web Services client makes a service request, Oracle Application Server Web Services invokes a Web Services Servlet that runs the method that implements the service request. There are very few restrictions on what actions Web Services can perform. At a minimum, Web Services generate some data that is sent to a client or perform an action as specified by a Web Service request.
This section shows how to write a stateful and a stateless Java Web Service that returns a string, "Hello World". The stateful service also returns an integer running count of the number of method calls to the service. This Java Web Service receives a client request and generates a response that is returned to the Web Service client.
The sample code is supplied on the Oracle Technology Network Web site,
After expanding the Web Services
demo.zipfile, the Java class based Web Service is in the directory under
webservices/demo/basic/java_serviceson UNIX or in
Writing Stateless and Stateful Java Web Services
Oracle Application Server Web Services supports stateful and stateless implementations for Java classes running as Web Services, as follows:
- For a stateful Java implementation, Oracle Application Server Web Services uses a single Java instance to serve the Web Service requests from an individual client.
- For a stateless Java implementation, Oracle Application Server Web Services creates multiple instances of the Java class in a pool, any one of which may be used to service a request. After servicing the request, the object is returned to the pool for use by a subsequent request.