JMS样本

1、JMS它是一个制作AS提供Message服务。它接受由生成的消息(Message Provider)消息发出，并转发消息到消息消费者(Message  Consumer)。
2、JMS提供2的消息服务的类型：(1)Queue。这点，息消费者使用。(2)Topic。即公布和订阅。每一个消息能够转发给全部的订阅者(消费者)。
3、WEBLOGIC 8下的JMS配置：
(1)配置JMS Connection Factory
(2)配置JMS File Store(眼下所找到的文档都是配置File Store,事实上在详细的应用中。可能JMS JDBC Store更广泛，但临时没有找到资料)
(3)配置JMS Server
(4)在JMS Server的destinations中配置JMS Queue或者JMS Topic
当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
一个消息发送者的样例：

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JNDI
String 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";//模拟须要发送的消息
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;//JMS Connection Factory的获得

obj = context.lookup(queueName);
Queue queue = (Queue) obj;//JMS Queue或者JMS Topic的获得
QueueConnection queueConnection=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) {
queueSession.commit();
}
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，须要用setMessageListener将MessageListener接口绑定到MessageReceiver
消息消费者必须实现了MessageListener接口，须要定义onMessage事件方法。

一个消息消费者的样例：

package myjms;
import java.util.*;
import javax.naming.*;
import javax.jms.*;
public class MessageReciever
implements 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 Bean
MDB它实际上是一个消息消费者client计划。它由AS EJB Container要管理。在JBUILDER产生MDB很easy。