版本 5 Hello World

使用 ActiveMQ Classic 5 > 版本 5 Hello World

以下是一個非常簡單的 JMS 應用程式，具有多個並行的消費者和生產者。請參閱初始設定指南，以了解如何正確設定您的類別路徑。

執行此範例後，您可能會執行的操作

設定一個訊息代理程式 (broker) 而不是直接使用 org.activemq.broker.impl.Main 類別
使用 JNDI 來查找 javax.jms.ConnectionFactory，而不是直接建立 ActiveMQConnectionFactory。
實作 javax.jms.MessageListener 介面，而不是呼叫 consumer.receive()
使用交易式連線
使用主題 (Topic) 而不是佇列 (queue)

此範例的重點是向您展示以直接的方式使用 JMS 所需的基本程式碼。消費者和生產者可以很容易地在完全不同的機器或不同的程序中。

App.java

import org.apache.activemq.ActiveMQConnectionFactory;

import javax.jms.Connection;
import javax.jms.DeliveryMode;
import javax.jms.Destination;
import javax.jms.ExceptionListener;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;

/**
 * Hello world!
 */
public class App {

    public static void main(String[] args) throws Exception {
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        Thread.sleep(1000);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        Thread.sleep(1000);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldProducer(), false);
        Thread.sleep(1000);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldConsumer(), false);
        thread(new HelloWorldProducer(), false);
    }

    public static void thread(Runnable runnable, boolean daemon) {
        Thread brokerThread = new Thread(runnable);
        brokerThread.setDaemon(daemon);
        brokerThread.start();
    }

    public static class HelloWorldProducer implements Runnable {
        public void run() {
            try {
                // Create a ConnectionFactory
                ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("vm://127.0.0.1");

                // Create a Connection
                Connection connection = connectionFactory.createConnection();
                connection.start();

                // Create a Session
                Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

                // Create the destination (Topic or Queue)
                Destination destination = session.createQueue("TEST.FOO");

                // Create a MessageProducer from the Session to the Topic or Queue
                MessageProducer producer = session.createProducer(destination);
                producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);

                // Create a messages
                String text = "Hello world! From: " + Thread.currentThread().getName() + " : " + this.hashCode();
                TextMessage message = session.createTextMessage(text);

                // Tell the producer to send the message
                System.out.println("Sent message: "+ message.hashCode() + " : " + Thread.currentThread().getName());
                producer.send(message);

                // Clean up
                session.close();
                connection.close();
            }
            catch (Exception e) {
                System.out.println("Caught: " + e);
                e.printStackTrace();
            }
        }
    }

    public static class HelloWorldConsumer implements Runnable, ExceptionListener {
        public void run() {
            try {

                // Create a ConnectionFactory
                ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("vm://127.0.0.1");

                // Create a Connection
                Connection connection = connectionFactory.createConnection();
                connection.start();

                connection.setExceptionListener(this);

                // Create a Session
                Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

                // Create the destination (Topic or Queue)
                Destination destination = session.createQueue("TEST.FOO");

                // Create a MessageConsumer from the Session to the Topic or Queue
                MessageConsumer consumer = session.createConsumer(destination);

                // Wait for a message
                Message message = consumer.receive(1000);

                if (message instanceof TextMessage) {
                    TextMessage textMessage = (TextMessage) message;
                    String text = textMessage.getText();
                    System.out.println("Received: " + text);
                } else {
                    System.out.println("Received: " + message);
                }

                consumer.close();
                session.close();
                connection.close();
            } catch (Exception e) {
                System.out.println("Caught: " + e);
                e.printStackTrace();
            }
        }

        public synchronized void onException(JMSException ex) {
            System.out.println("JMS Exception occured.  Shutting down client.");
        }
    }
}