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A Web Service Example: HelloServiceBean

This example demonstrates a simple web service that generates a response based on information received from the client. HelloServiceBean is a stateless session bean that implements a single method, sayHello. This method matches the sayHello method invoked by the client described in A Simple JAX-WS Client (page 503).

The Web Service Endpoint Implementation Class

HelloServiceBean is the endpoint implementation class. The endpoint implementation class is typically the primary programming artifact for enterprise bean web service endpoints. The web service endpoint implementation class has the following requirements:

The class must be annotated with either the javax.jws.WebService or javax.jws.WebServiceProvider annotations.
The implementing class may explicitly reference an SEI through the endpointInterface element of the @WebService annotation, but is not required to do so. If no endpointInterface is not specified in @WebService, an SEI is implicitly defined for the implementing class.
The business methods of the implementing class must be public, and must not be declared static or final.
Business methods that are exposed to web service clients must be annotated with javax.jws.WebMethod.
Business methods that are exposed to web service clients must have JAX-B-compatible parameters and return types. See Default Data Type Bindings (page 512).
The implementing class must not be declared final and must not be abstract.
The implementing class must have a default public constructor.
The endpoint class must be annotated @Stateless.
The implementing class must not define the finalize method.
The implementing class may use the javax.annotation.PostConstruct or javax.annotation.PreDestroy annotations on its methods for lifecycle event callbacks.

The @PostConstruct method is called by the container before the implementing class begins responding to web service clients.

The @PreDestroy method is called by the container before the endpoint is removed from operation.

Stateless Session Bean Implementation Class

The HelloServiceBean class implements the sayHello method, which is annotated @WebMethod. The source code for the HelloServiceBean class follows:

package com.sun.tutorial.javaee.ejb;

import javax.ejb.Stateless;
import javax.jws.WebMethod;
import javax.jws.WebService;

@Stateless
@WebService
public class HelloServiceBean {
  private String message = "Hello, ";

  public void HelloServiceBean() {}

  @WebMethod
  public String sayHello(String name) {
    return message + name + ".";
  }
} 

Building and Packaging helloservice

In a terminal window, go to the <INSTALL>/javaeetutorial5/examples/ejb/helloservice/ directory. To build helloservice, type the following command:

ant 

This runs the default task, which compiles the source files and packages the application into an JAR file located at <INSTALL>/examples/ejb/helloservice/dist/helloservice.jar.

Deploying helloservice

Now that the Java EE application contains the enterprise bean deploy the helloservice application using ant:

ant deploy 

Upon deployment, the Application Server generates additional artifacts required for web service invocation, including the WSDL file.

Testing the Service Without a Client

The Application Server Admin Console allows you to test the methods of a web service endpoint. To test the sayHello method of HelloServiceBean, do the following:

Open the Admin Console by opening the following URL in a web browser:

  http://localhost:4848/

Enter the admin username and password to log in to the Admin Console.
Click Web Services in the left pane of the Admin Console.
Click helloservice.
Click Test.
Under Methods, enter a name as the parameter to the sayHello method.
Click the sayHello button.

This will take you to the sayHello Method invocation page.

Under Method returned, you'll see the response from the endpoint.

All of the material in The Java™ EE 5 Tutorial is copyright-protected and may not be published in other works without express written permission from Sun Microsystems.