EJB 3.0入门

import javax.ejb.MessageDriven;

import javax.ejb.ActivationConfigProperty;

import javax.ejb.Inject;

import javax.jms.*;

import java.util.*;

import javax.ejb.TimedObject;

import javax.ejb.Timer;

import javax.ejb.TimerService;

@MessageDriven(

activationConfig = {

@ActivationConfigProperty(propertyName="connectionFactoryJndiName", 
propertyValue="jms/TopicConnectionFactory"),

@ActivationConfigProperty(propertyName="destinationName", 
propertyValue="jms/myTopic"),

@ActivationConfigProperty(propertyName="destinationType", 
propertyValue="javax.jms.Topic"),

@ActivationConfigProperty(propertyName="messageSelector", 
propertyValue="RECIPIENT = 'MDB'")

}

)
/**

*监听可配置JMS队列或者主题和通过当一个消息发送到队列或者主题

*调用它的onMessage()方法得到提醒的一个简单的消息驱动

*该Bean打印消息的内容

*/
public class MessageLogger implements MessageListener, TimedObject

{
@Inject javax.ejb.MessageDrivenContext mc;
public void onMessage(Message message)

{

System.out.println("onMessage() - " + message);

try

{

String subject = message.getStringProperty("subject");

String inmessage = message.getStringProperty("message");

System.out.println("Message received\n\tDate: " + new java.util.Date() + 
"\n\tSubject: " + subject + "\n\tMessage: " + inmessage + "\n");

System.out.println("Creating Timer a single event timer");

TimerService ts = mc.getTimerService();

Timer timer = ts.createTimer(30000, subject);

System.out.println("Timer created by MDB at: " + 
new Date(System.currentTimeMillis()) +" with info: "+subject);

}

catch (Throwable ex)

{

ex.printStackTrace();

}

}
public void ejbTimeout(Timer timer)

{

System.out.println("EJB 3.0: Timer with MDB");

System.out.println("ejbTimeout() called at: " + 
new Date(System.currentTimeMillis()));

return;

}

}

import javax.naming.Context;

import javax.naming.InitialContext;
/**

* 一个调用无状态会话Bean中方法的简单的Bean客户端

*/
public class CalculateejbClient

{

public static void main(String [] args)

{

Context context = new InitialContext();

CalculateEJB myejb =

(CalculateEJB)context.lookup("java:comp/env/ejb/CalculateEJB");

myejb.incrementValue();

}

}