EJB之消息驱动bean

java消息服务(简称JMS)是用于访问企业消息系统的开发商的API，可以概括为应用程序A发送一条消息到消息服务器的某个目的地，然后消息服务器将消息发送给监听这个目的地的程序B，JMS支持两种消息传递模型，点对点(简称PTP)和发布/订阅(简称pub/sub)，PTP规定一条消息只能发送给一个接收方，pub/sub允许一条消息发送给多个接收方，以下是个JMS的小例子
1.首先我们需要配置消息到达的目的地址，命名规范为*-service.xml,每个应用服务器的配置都不同，我用的是JBoss，代码如下

<?xml version="1.0" encoding="UTF-8"?> 
<server>
	  <mbean code="org.jboss.mq.server.jmx.Queue" 
		name="jboss.mq.destination:service=Queue,name=liaokangQueue"> 
		<attribute name="JNDIName">queue/liaokangQueue</attribute>
	 <depends optional-attribute-name="DestinationManager">jboss.mq:service=DestinationManager</depends>    
	</mbean> 

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

</server>

将其部署在server\default\deploy目录下

2.新建一个java项目，并将jboss的client目录下的jar文件全部引入，新建一个类来向目的地发送消息，代码如下，这是Queue消息

package com.lamp.app;

import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSession;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class QueueSender {
	
	public static void main(String[] args) {
		try {
			InitialContext ctx = new InitialContext();
			QueueConnectionFactory factory = (QueueConnectionFactory)ctx.lookup("QueueConnectionFactory");
			QueueConnection conn = factory.createQueueConnection();
			QueueSession session = conn.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
			Destination destination = (Destination) ctx.lookup("queue/liaokangQueue");
			MessageProducer producer = session.createProducer(destination);
			producer.send(session.createTextMessage("欢迎来到消息驱动的世界,这是queue消息"));
			session.close();
			conn.close();
		} catch (NamingException e) {
			e.printStackTrace();
		} catch (JMSException e) {
			e.printStackTrace();
		}
	}
}

当然不要忘记在src目录下新建JNDI的配置文件jndi.properties
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.provider.url=localhost:1099

然后采用消息驱动bean来接受消息

package com.lamp.message;

import javax.ejb.ActivationConfigProperty;
import javax.ejb.MessageDriven;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.TextMessage;


@MessageDriven(activationConfig={
	@ActivationConfigProperty(propertyName="destinationType",propertyValue="javax.jms.Queue"),
	@ActivationConfigProperty(propertyName="destination",propertyValue="queue/liaokangQueue")
})
public class MessageDriverBean implements MessageListener{

	public void onMessage(Message message) {
		TextMessage tmsg = (TextMessage)message;
		try {
			System.out.println(tmsg.getText());
		} catch (JMSException e) {
			e.printStackTrace();
		}
	}

}

以下是Topic消息的发送
Topic消息发送类

package com.lamp.app;

import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.TopicConnection;
import javax.jms.TopicConnectionFactory;
import javax.jms.TopicSession;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class TopicSender {

	
	public static void main(String[] args) {

		try {
			InitialContext ctx = new InitialContext();
			TopicConnectionFactory factory = (TopicConnectionFactory) ctx
					.lookup("TopicConnectionFactory");
			TopicConnection conn = factory.createTopicConnection();
			TopicSession session = conn.createTopicSession(false,
					TopicSession.AUTO_ACKNOWLEDGE);
			Destination destination = (Destination) ctx
					.lookup("topic/liaokangTopic");
			MessageProducer producer = session.createProducer(destination);
			producer.send(session.createTextMessage("欢迎来到消息驱动的世界,这是topic消息"));
			session.close();
			conn.close();
		} catch (NamingException e) {
			e.printStackTrace();
		} catch (JMSException e) {
			e.printStackTrace();
		}

	}

}

topic消息类型接收类

package com.lamp.message;

import javax.ejb.ActivationConfigProperty;
import javax.ejb.MessageDriven;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.TextMessage;


@MessageDriven(activationConfig={
		@ActivationConfigProperty(propertyName="destinationType",propertyValue="javax.jms.Topic"),
		@ActivationConfigProperty(propertyName="destination",propertyValue="topic/liaokangTopic")
	})
public class TopicReceiver implements MessageListener {

	public void onMessage(Message message) {
		TextMessage tmsg = (TextMessage)message;
		try {
			System.out.println(tmsg.getText());
		} catch (JMSException e) {
			e.printStackTrace();
		}
	}

}

不同Queue的是你可以新建多个消息接受类来接受同一个目的地Topic类型的消息
最后将工程打包成jar，部署到JBossserver\default\deploy目录下，在发送方类中运行main方法

猜你喜欢