myeclipse8+jboss5开发EJB3消息驱动Bean(MDB)实例

最新推荐文章于 2016-08-25 13:41:57 发布

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本文介绍了一个具体的EJB3项目与JMS集成的例子，包括如何在Web项目中发送消息到队列，以及如何在EJB项目中实现MessageDrivenBean接收这些消息。

先看最后的目录结构：

mdb为EJB3项目；mdbTest为Web项目，add project:

上代码:

web项目中的servlet: mdb.java:

import java.io.IOException;
import java.io.PrintWriter;
import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSender;
import javax.jms.QueueSession;
import javax.jms.TextMessage;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class mdb extends HttpServlet {
 /**
  * The doGet method of the servlet. <br>
  *
  * This method is called when a form has its tag value method equals to get.
  * 
  * @param request the request send by the client to the server
  * @param response the response send by the server to the client
  * @throws ServletException if an error occurred
  * @throws IOException if an error occurred
  */
 public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
  out.println("<HTML>");
  out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
  out.println("  <BODY>");
    try {
      //获取QueueConnectionFactory对象
      InitialContext context =new InitialContext();
      QueueConnectionFactory factory =(QueueConnectionFactory)context.lookup("ConnectionFactory");
      
      //创建QueueConnection
      QueueConnection connnection =factory.createQueueConnection();
      
      //创建QueueSession
      QueueSession session =connnection.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
      
      //获取Destination对象
      Queue queue =(Queue)context.lookup("queue/myqueue");
      
      //获取文本信息
      TextMessage msg =session.createTextMessage();
      //创建发布者
      QueueSender sender =session.createSender(queue);
      
      for(int i=0;i<5;i++){
       msg.setText("世界你好啊！      "+i);
       //发送消息
       sender.send(msg);
      }
      
      System.out.println("消息已发送");
     } catch (NamingException e) {
      e.printStackTrace();
     } catch (JMSException e) {
      e.printStackTrace();
     }
  
  out.println("  </BODY>");
  out.println("</HTML>");
  out.flush();
  out.close();
 }
}

ejb项目中的Message Driven Bean: MyQueueMDBBean.java

package com.test.ejb;
import javax.ejb.EJBException;
import javax.ejb.MessageDriven;
import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.TextMessage;
import javax.ejb.ActivationConfigProperty;
@MessageDriven(
 activationConfig ={
   @ActivationConfigProperty(propertyName="destinationType",propertyValue="javax.jms.Queue"),
   @ActivationConfigProperty(propertyName="destination",propertyValue="queue/myqueue")
 }
)
 
public class MyQueueMDBBean implements MessageDrivenBean,MessageListener {
  private  MessageDrivenContext mdc = null;
  
  public MyQueueMDBBean(){
   System.out.println("初始化构造函数MDBean()");
  }
 public void onMessage(Message msg) {
  TextMessage textMessage =(TextMessage)msg;
  
  try {
   System.out.println("MyQueueMDBBean被调用了【"+textMessage.getText()+"】");
  } catch (JMSException e) {
   e.printStackTrace();
  }
 }
 
 public void ejbCreate() {
  System.out.println("MDBean.ejbCreate()");
 }
public void ejbRemove() throws EJBException {
 //A container invokes this method before it ends the life of the message-driven object. 
 System.out.println("MDBean.remove()");
}
public void setMessageDrivenContext(MessageDrivenContext mdc)throws EJBException {
 //Set the associated message-driven context.
 System.out.println("MDBean.setMessageDrivenContext()");
 this.mdc=mdc;
}
}

在deploy目录下的mail-service.xml下加上代码：

<mbean code="org.jboss.mq.server.jmx.Queue" name="jboss.org.destination:server=Queue,name=myqueue" > 
　　<attribute name="JNDIName" >queue/myqueue</attribute> 
　　<depends optional-attribute-name = "DestinationManager" > jboss.mq:service=DestinationManager </depends> 
</mbean>

现在部署此ejb。

并新建一个空目录：queue

通过jboss在queue中生成文件：myqueue-service.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<server>
    <mbean xmbean-dd="xmdesc/Queue-xmbean.xml" name="jboss.messaging.destination:service=Queue,name=myQueue" code="org.jboss.jms.server.destination.QueueService">
        <attribute name="SecurityConfig">
            <security>
                <role create="true" name="guest2" read="true" write="true"/>
            </security>
        </attribute>
        <attribute name="PageSize">2000</attribute>
        <attribute name="ServerPeer">jboss.messaging:service=ServerPeer</attribute>
        <attribute name="FullSize">200000</attribute>
        <attribute name="JNDIName">queue/myQueue</attribute>
        <attribute name="RedeliveryDelay">-1</attribute>
        <attribute name="DownCacheSize">2000</attribute>
        <attribute name="MaxSize">-1</attribute>
        <attribute name="MaxDeliveryAttempts">-1</attribute>
        <depends optional-attribute-name="ServerPeer">jboss.messaging:service=ServerPeer</depends>
        <depends>jboss.messaging:service=PostOffice</depends>
    </mbean>
</server>

最后jboss配置一下：

部署测试：http://localhost:8080/mdbTest/mdb

在jboss命令行输出：（初次运行结果）

21:53:49,847 INFO [STDOUT] MyQueueMDBBean被调用了【世界你好啊！      0】
21:53:49,851 INFO [STDOUT] 初始化构造函数MDBean()
21:53:49,852 INFO [STDOUT] 消息已发送
21:53:49,858 INFO [STDOUT] MyQueueMDBBean被调用了【世界你好啊！      1】
21:53:49,864 INFO [STDOUT] MyQueueMDBBean被调用了【世界你好啊！      2】
21:53:49,866 INFO [STDOUT] MyQueueMDBBean被调用了【世界你好啊！      3】
21:53:49,868 INFO [STDOUT] MyQueueMDBBean被调用了【世界你好啊！      4】

本人亲测，就是上面的效果。当然，若版本不致的话，可能出现问题。