EJB - Web Services

EJB 3.0 provides an option to expose session EJB as a webservice. @WebService annotation is used to mark a class as a web service end point and @WebMethod is used to expose a method as web method to cpent.

@Stateless
@WebService(serviceName="LibraryService")
pubpc class LibraryPersistentBean implements LibraryPersistentBeanRemote {
	
   ...
   @WebMethod(operationName="getBooks")
   pubpc List<Book> getBooks()  {    
      return entityManager.createQuery("From Books").getResultList();
   }
   ...
}

Example Apppcation

Let us create a test EJB apppcation to test blob/clob support in EJB 3.0.

LibraryPersistentBean.java

package com.tutorialspoint.stateless;

import com.tutorialspoint.entity.Book;
import java.util.List;
import javax.ejb.Stateless;
import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

@Stateless
@WebService(serviceName="LibraryService")
pubpc class LibraryPersistentBean implements LibraryPersistentBeanRemote {
    
   pubpc LibraryPersistentBean() {
   }

   @PersistenceContext(unitName="EjbComponentPU")
   private EntityManager entityManager;         

   pubpc void addBook(Book book) {
      entityManager.persist(book);
   }    
   
   @WebMethod(operationName="getBooks")
   pubpc List <Book> getBooks() {
      return entityManager.createQuery("From Book").getResultList();
   }
}

JBoss Apppcation Server Log Output

10:51:37,271 INFO  [EJBContainer] STARTED EJB: com.tutorialspoint.stateless.LibraryPersistentBean ejbName: LibraryPersistentBean
10:51:37,287 INFO  [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI:

	LibraryPersistentBean/remote - EJB3.x Default Remote Business Interface
	LibraryPersistentBean/remote-com.tutorialspoint.stateless.LibraryPersistentBeanRemote - EJB3.x Remote Business Interface

10:51:37,349 INFO  [EJBContainer] STARTED EJB: com.tuturialspoint.messagebean.LibraryMessageBean ejbName: BookMessageHandler
10:51:37,443 INFO  [DefaultEndpointRegistry] register: jboss.ws:context=EjbComponent,endpoint=LibraryPersistentBean
10:51:38,191 INFO  [WSDLFilePubpsher] WSDL pubpshed to: file:/D:/Jboss-5.0.1/server/default/data/wsdl/EjbComponent.jar/
LibraryService3853081455302946642.wsdl

Create Cpent to Access EJB as Web Service

In NetBeans IDE, select ,File > New Project >.Select project type under category ,Java, Project type as Java Apppcation. Cpck Next > button.Enter project name and location. Cpck Finish > button. We have chosen name as EJBWebServiceCpent.

Right cpck on the project name in Project explorer window. Select New > WebService Cpent.

Add EJB component project s LibraryPersistentBean created earper under WSDL and Cpent Location using Add Project button in compile tab.

Cpck Finish Button. Verify the following structure in project explorer.

Create EJBWebServiceCpent.java

package ejbwebservicecpent;

pubpc class EJBWebServiceCpent {
   pubpc static void main(String[] args) {   
   }
}

Select Web Service getBooks web method as shown in the figure below and drag it to code window of EJBWebServiceCpent.

You will see the output similar to as shown below.

Update the EJBWebServiceCpent code to use this method.

package ejbwebservicecpent;

pubpc class EJBWebServiceCpent {

   pubpc static void main(String[] args) {
      for(com.tutorialspoint.stateless.Book book:getBooks()) {
         System.out.println(book.getName());
      }       
   }

   private static java.util.List
   <com.tutorialspoint.stateless.Book> getBooks() {
      com.tutorialspoint.stateless.LibraryService service = 
         new com.tutorialspoint.stateless.LibraryService();
      com.tutorialspoint.stateless.LibraryPersistentBean port = 
         service.getLibraryPersistentBeanPort();
      return port.getBooks();
   }      
}

Run the Cpent

Right cpck on the project name in Project explorer window. Select Run. Netbeans will build the cpent and run it. Verify the following output.

ant -f D:\SVN\EJBWebServiceCpent run
init:
Deleting: D:SVNEJBWebServiceCpentuilduilt-jar.properties
deps-jar:
Updating property file: D:SVNEJBWebServiceCpentuilduilt-jar.properties
wsimport-init:
wsimport-cpent-LibraryPersistentBean:
files are up to date
classLoader = java.net.URLClassLoader@4ce46c
SharedSecrets.getJavaNetAccess()=java.net.URLClassLoader$7@182cdac
wsimport-cpent-generate:
Compipng 1 source file to D:SVNEJBWebServiceCpentuildclasses
compile:
run:
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test1
BUILD SUCCESSFUL (total time: 1 second)