JMS入门之实例

JMS是一个由AS提供的Message服务。

它能接受消息产生者(Message Provider)所发出的消息，并把消息转发给消息消费者(Message Consumer)。

2、JMS提供2种类型的消息服务：(1)Queue，即点对点，每个消息只转发给一个消息消费者使用。

(2)Topic，即发布和订阅，每个消息可以转发给所有的订阅者(消费者)。

3、WEBLOGIC 8下的JMS配置：(1)配置JMS Connection Factory(2)配置JMS File Store(目前所找到的文档都是配置File Store,其实在具体的应用中，可能JMS JDBC Store更广泛，但暂时没有找到资料)(3)配置JMS Server(4)在JMS Server的destinations中配置JMS Queue或者JMS Topic其中提供给消息产生者和消息消费者使用的是JMS Connection Factory的JNDI和JMS Queue或者JMS Topic的JNDI。

4、消息产生者向JMS发送消息的步骤：(1)使用JNDI查询对象JMS ConnectionFactory和Destination(JMS Queue/Topic)(2)使用管理对象JMS ConnectionFactory建立连接Connection(3)使用连接Connection 建立会话Session(4)使用会话Session和管理对象Destination创建消息生产者MessageSender(5)使用消息生产者MessageSender发送消息一个消息发送者的例子：package myjms;import java.util.*;import javax.naming.*;import javax.jms.*;public class MessageProducter {public static void main(String[] args) {String queueConnectionFactoryName = "myjmsconnectionfactory"; //JMS Connection Factory的JNDIString queueName = "myjmsqueue"; //JMS Queue或者JMS Topic的JNDI boolean transacted = false;//transaction模式int acknowledgementMode =Session.AUTO_ACKNOWLEDGE;//acknowledgement模式String message="Message need to send";//模拟需要发送的消息Properties properties = new Properties();properties.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLIniti alContextFactory");properties.put(Context.PROVIDER_URL, "t3://localhost:7001");try {Context context = new InitialContext(properties);Object obj = context.lookup(queueConnectionFactoryName);QueueConnectionFactory queueConnectionFactory = (QueueConnectionFactory) obj;//JMS Connection Factory的获得obj = context.lookup(queueName);Queue queue = (Queue) obj;//JMS Queue或者JMS Topic的获得QueueConnectionqueueConnection=queueConnectionFactory.createQueueConnection();//产生连接queueConnection.start();QueueSession queueSession =queueConnection.createQueueSession(transacted, acknowledgementMode);TextMessage textMessage = queueSession.createTextMessage();textMessage.clearBody();textMessage.setText(message);QueueSender queueSender = queueSession.createSender(queue);queueSender.send(textMessage);if (transacted) {mit();}if (queueSender != null) {queueSender.close();}if (queueSession != null) {queueSession.close();}if (queueConnection != null) {queueConnection.close();}}catch(Exception ex){ex.printStackTrace();}}}5、消息消费者从JMS接受消息的步骤：(1)使用JNDI查询对象JMS ConnectionFactory和Destination(JMS Queue/Topic)(2)使用管理对象JMS ConnectionFactory建立连接Connection(3)使用连接Connection 建立会话Session(4)使用会话Session和管理对象Destination创建消息消费者MessageReceiver(5)使用消息消费者MessageReceiver接受消息，需要用setMessageListener将MessageListener接口绑定到MessageReceiver消息消费者必须实现了MessageListener接口，需要定义onMessage事件方法。

一个消息消费者的例子：package myjms;import java.util.*;import javax.naming.*;import javax.jms.*;public class MessageRecieverimplements MessageListener {public void onMessage(Message message) {if (message instanceof TextMessage) {TextMessage textMessage = (TextMessage) message;try {System.out.println("Message content is:" + textMessage.getText());}catch (JMSException e) {e.printStackTrace();}}}public static void main(String[] args) {MessageReciever msgRcvr=new MessageReciever();String queueConnectionFactoryName = "myjmsconnectionfactory";String queueName = "myjmsqueue";boolean transacted = false;int acknowledgementMode = Session.AUTO_ACKNOWLEDGE;Properties properties = new Properties();properties.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");properties.put(Context.PROVIDER_URL, "t3://localhost:7001");try {Context context = new InitialContext(properties);Object obj = context.lookup(queueConnectionFactoryName);QueueConnectionFactory queueConnectionFactory = (QueueConnectionFactory)obj;obj = context.lookup(queueName);Queue queue = (Queue) obj;QueueConnection queueConnection = queueConnectionFactory.createQueueConnection();queueConnection.start();QueueSession queueSession =queueConnection.createQueueSession(transacted,acknowledgementMode);QueueReceiver queueReceiver = queueSession.createReceiver(queue);queueReceiver.setMessageListener(msgRcvr);synchronized(msgRcvr){msgRcvr.wait(100000);}if (queueReceiver != null) {queueReceiver.close();}if (queueSession != null) {queueSession.close();}if (queueConnection != null) {queueConnection.close();}}catch (Exception ex) {ex.printStackTrace();}}}6、Message-driven BeanMDB实际上就是一个消息消费者的客户端程序。

它由AS EJB Container来管理。

在JBUILDER生成一个MDB非常简单。