初JMS(java消息服务发布/订阅demo_01)

Hi
今天那个实例来介绍下JMS发布/订阅 .现在网络聊天的需求可以完美的映射到发布.订阅消息的传达模型之上的。
实例:、如果要运行Chat。需要使用支持JNDI和JMS的JMS提供者。我使用的开源JMS提供者：ActiveMq (版本apache-activemq-5.5.0)
apache-activemq-5.5.0下载地址
http://activemq.apache.org/activemq-550-release.html

下载后运行D:\Jar\apache-activemq-5.5.0\bin\activemq.bat
访问http://localhost:8161/admin/

页面显示如下表示服务开启

Welcome to the ActiveMQ Console of localhost (ID:dnepc504-1186-1303391964578-0:1) 

You can find more information about ActiveMQ on the Apache ActiveMQ Site 

Chat.java

package iteye.JMS_Exception.chat;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Properties;

import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.jms.TopicConnection;
import javax.jms.TopicConnectionFactory;
import javax.jms.TopicPublisher;
import javax.jms.TopicSession;
import javax.jms.TopicSubscriber;
import javax.naming.InitialContext;

/**
 * Chat 类自身实现了MessageListener接口和onMessage方法
 * Email: [e-mail]
 * @author PC504
 *
 */
public class Chat implements javax.jms.MessageListener{
    private TopicSession pubSession;
    private TopicPublisher publisher;
    private TopicConnection connection;
    private String username;

    /* 初始化Chat */
    public Chat(String topicFactory, String topicName, String username) 
        throws Exception {
    	
    	// 设置JNDI连接参数
    	Properties env = new Properties();
    	env.put(javax.naming.Context.SECURITY_PRINCIPAL, "system");
    	env.put(javax.naming.Context.SECURITY_CREDENTIALS, "manager");
    	env.put(javax.naming.Context.INITIAL_CONTEXT_FACTORY,"org.apache.activemq.jndi.ActiveMQInitialContextFactory");
    	env.put(javax.naming.Context.PROVIDER_URL,"tcp://127.0.0.1:61616");
    	
    	//实例化InitialContext对象以后
    	//就可以使用它在消息传送服务器的命名服务中查找TopicConnectionFactory
        InitialContext ctx = new InitialContext(env);

        //创建到JMS提供者的发布/订阅的 TopicConnection
        TopicConnectionFactory conFactory = 
        	(TopicConnectionFactory)ctx.lookup(topicFactory);

        //客户端使用一个 TopicConnectionFactory 对象
        //来创建到JMS提供者的发布/订阅的 TopicConnection
        TopicConnection connection = conFactory.createTopicConnection();
        
        // TopicSession 用于创建Message.TopicPublisher .TopicSubscriber对象的工厂.我们创建两个JMS会话对象
        //false意味创建的TopicSession将不是事务性的。
        //AUTO_ACKNOWLEDGE 意味消息将在客户端接收之后自动确定
        TopicSession pubSession = connection.createTopicSession(
        	false, Session.AUTO_ACKNOWLEDGE); 
        //pubSession.createDurableSubscriber(topic, topicName)
        TopicSession subSession = connection.createTopicSession(
        	false, Session.AUTO_ACKNOWLEDGE);

        // 查找JMS主题
        Topic chatTopic = (Topic)ctx.lookup(topicName);

        // 创建JSM 发布/订阅
        
        TopicPublisher publisher = 
            pubSession.createPublisher(chatTopic);
        TopicSubscriber subscriber = 
            subSession.createSubscriber(chatTopic, null, true);

        //设置一个JMS消息监听器
        
        subscriber.setMessageListener(this);

        this.connection = connection;
        this.pubSession = pubSession;
        this.publisher = publisher;
        this.username = username;

        // 启动JMS连接.允许传达消息
        connection.start( );
    }

    /* 接收来自TopicSubscriber的消息
     * 当TopicSubscriber从它的主题接收一条消息,
     * 调用了它的MessageListener对象的onMessage()方法
     *  */
    public void onMessage(Message message) {
        try {
            TextMessage textMessage = (TextMessage) message;
            String text = textMessage.getText( );
            System.out.println(text);
        } catch (JMSException jmse){ jmse.printStackTrace( ); }
    }

    /*使用发布者创建并发送消息 */
    protected void writeMessage(String text) throws JMSException {
    	//TextMessage类型携带了一个String作为有效负载.
    	//生产出"准备就绪可传达的TextMessage对象"
        TextMessage message = pubSession.createTextMessage( );
        //MapMessage mapMessage = pubSession.createMapMessage();
        message.setText(username+":"+text);
        System.out.println(message.getText());
        publisher.publish(message);
    }

    /* 关闭JMS连接 */
    public void close( ) throws JMSException {
        connection.close( );
    }

    /* 运行Main */
    public static void main(String [] args){
        try{
            if (args.length!=3)
            System.out.println("Factory, Topic, or username missing");
            Chat chat = new Chat(args[0],args[1],args[2]);
            // 从命令行读取
            BufferedReader commandLine = new 
              java.io.BufferedReader(new InputStreamReader(System.in));

            // 键入"exit" 停止运行
            while(true){
                String s = commandLine.readLine( );
                if (s.equalsIgnoreCase("exit")){
                    chat.close( ); 
                    System.exit(0);
                } else 
                    chat.writeMessage(s);
            }
        } catch (Exception e){ e.printStackTrace( ); }
    }
}

jar:

javac iteye\JMS_Exception\chat\Chat.java
李雷和韩梅梅
Han Meimei: Hello!
Li Lei:Hello!
Han Meimei:My name is Han Meimei.What is your name?
Li Lei:My name is LI lei.


在前面我们已经定义了一个名称为TopicCF的主题链接工厂.以及名为Topic1的一个Topic主题.因此要为一个名为LiLei.HanMeimei的用户执行Chat.需要使用以下命令
java iteye.JMS_Exception.chat.Chat TopicCF topic1 LiLei
java iteye.JMS_Exception.chat.Chat TopicCF topic1 HanMeimei

图: