ActiveMQ

Posted by Bruce Tsai
08/01/2016

• ActiveMQ

ActiveMQ 是 Apache 下的一個子項目。類似於 ZeroMQ，它能夠以代理人和點對點的技術實現佇列。同時類似於 RabbitMQ，只需少量代碼就可以高效地實現高級應用場景。

使用範例

• Apache ActiveMQ ™ -- Hello World

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://localhost");

                // 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://localhost");

                // 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.");
        }
    }
}