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();
}
}