EJB Web Services - EJB

EJB3.0暴露会话EJB作为Web服务提供选项。@WebService注释是用来标记一类作为一个Web服务端点，并使用@WebMethod是用来作为客户端的Web方法的公开方法。

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

   ...
   @WebMethod(operationName="getBooks")
   public List<Book> getBooks()  {    
      return entityManager.createQuery("From Books").getResultList();
   }
   ...
}

示例应用程序

让我们创建一个测试EJB在EJB3.0应用程序来测试BLOB/CLOB支持。

Step	Description
1	Create a project with a name EjbComponent under a package com.tutorialspoint.entity as explained in the EJB - Create Application chapter. Please use the project created in EJB - Persistence chapter as such for this chapter to understand clob/blob objects in ejb concepts.
2	Create LibraryPersistentBean.java under package com.tutorialspoint.stateless. Use EJB - Persistence chapter as reference. Keep rest of the files unchanged.
3	Clean and Build the application to make sure business logic is working as per the requirements.
4	Finally, deploy the application in the form of jar file on JBoss Application Server. JBoss Application server will get started automatically if it is not started yet.

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")
public class LibraryPersistentBean implements LibraryPersistentBeanRemote {

   public LibraryPersistentBean(){
   }

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

   public void addBook(Book book) {
      entityManager.persist(book);
   }    

   @WebMethod(operationName="getBooks")
   public List<Book> getBooks() {
      return entityManager.createQuery("From Book").getResultList();
   }
}

JBoss应用服务器的日志输出

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  [WSDLFilePublisher] WSDL published to: file:/D:/Jboss-5.0.1/server/default/data/wsdl/EjbComponent.jar/
LibraryService3853081455302946642.wsdl

创建客户端访问EJB作为Web服务

在NetBeansIDE中，选择File>NewProject>类别下选择项目类型，Java项目类型为Java应用。点击Next>按钮。输入项目的名称和位置。单击“Next>“按钮。我们选择名为EJBWebServiceClient。

右键点击项目名称在项目exporer窗口中。选择 New > WebService Client .

WSDL Client

添加EJB组件项目的LibraryPersistentBean早下创建WSDL和客户端位置使用在"编译"选项卡中添加项目“按钮。

Web Service Bean

单击“完成”按钮。在项目资源管理器验证以下结构。

Web Service Bean

Create EJBWebServiceClient.java

package ejbwebserviceclient;

public class EJBWebServiceClient {
   public static void main(String[] args) {   
   }
}

如下图所示，选择Web服务getBooks Web方法，将其拖动到代码窗口EJBWebServiceClient。

Web Service Method drag

会看到类似的输出如下所示。

Web Service Method dragged

更新EJBWebServiceClient的代码使用此方法。

package ejbwebserviceclient;

public class EJBWebServiceClient {

   public 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();
   }      
}

运行客户端

右键点击项目名称，项目资源管理器窗口。选择“Run”。 NetBeans将生成客户端并运行它。验证下面的输出。

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