JMS学习笔记之sample app

JMS学习笔记之sample app

Sample Chat App

JNDI

java.naming.factory.initial = org.apache.activemq.jndi.ActiveMQInitialContextFactory
java.naming.provider.url = tcp://localhost:61616
java.naming.security.principal=system
java.naming.security.credentials=manager

connectionFactoryNames = TopicCF
topic.topic1 = jms.topic1

Code

public class Chat implements javax.jms.MessageListener {

  private TopicPublisher topicPublisher;
  private TopicSubscriber topicSubscriber;
  private TopicSession publisherSession;
  private TopicSession subscriberSession;
  private TopicConnection topicConnection;
  private TopicConnectionFactory topicConnectionFactory;

  private String userName;


  public Chat (String connecionFactoryName, String topicName, String userName) throws Exception {
    InitialContext ctx = new InitialContext();

    // look up for JMS connection factory and create connection
    topicConnectionFactory = (TopicConnectionFactory) ctx.lookup(connecionFactoryName);
    topicConnection = topicConnectionFactory.createTopicConnection();

    // create two JMS session objects
    publisherSession = topicConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
    subscriberSession = topicConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);

    // look up for JMS topic
    Topic chatTopic = (Topic) ctx.lookup(topicName);


    // Topic publish and subscriber
    topicPublisher = publisherSession.createPublisher(chatTopic);

    topicSubscriber = subscriberSession.createSubscriber(chatTopic, null, true);
    topicSubscriber.setMessageListener(this);

    this.userName = userName;

    topicConnection.start();
  }

  private void writeMessage(String txt) throws JMSException {
    TextMessage message = publisherSession.createTextMessage();
    message.setText(this.userName +  ": " + txt);
    topicPublisher.publish(message);
  }

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

  }

  public void close() throws JMSException {
    topicConnection.close();
  }


  public static void main(String[] args) {
    try {
      if (args.length!=3) {
        System.out.println("Factory, topic or username missing");
      }

      // arg0 = topicFactory; arg1 = topic; arg2 = username
      Chat chat = new Chat(args[0], args[1], args[2]);

      // read from command line
      BufferedReader cli = new BufferedReader(new InputStreamReader(System.in));

      // loop until word "exit" is typed
      while (true) {
        String s = cli.readLine();
        if (s.equalsIgnoreCase("exit")) {
          chat.close();
          System.exit(0);
        } else {
          chat.writeMessage(s);
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

}

testing

Compile

javac -cp ../lib/javax.jms_1.1.1.jar Chat.java

Run

java -cp ../lib/javax.jms_1.1.1.jar:../lib/activemq-all-5.15.5.jar:. Chat TopicCF topic1 tom

java -cp ../lib/javax.jms_1.1.1.jar:../lib/activemq-all-5.15.5.jar:. Chat TopicCF topic1 jerry