ActiveMQ 鏡像隊列Mirrored Queues

概述

ActiveMQ中每個queue中的消息只能被一個consumer消費。然而，有時候你可能希望能夠監視生產者和消費者之間的消息流。你可以通過使用Virtual Destinations 來建立一個virtual queue 來把消息轉發到多個queues中。但是 爲系統中每個queue都進行如此的配置可能會很麻煩。
使用
ActiveMQ支持Mirrored Queues。Broker會把發送到某個queue的所有消息轉發到一個名稱類似的topic，因此監控程序只需要訂閱這個mirrored queue topic。爲了啓用Mirrored Queues，首先要將BrokerService的useMirroredQueues屬性設置成true，然後可以通過destinationInterceptors設置其它屬性，如mirror topic的前綴，缺省是“VirtualTopic.Mirror.”。
比如修改後綴的配置示例如下：
<destinationInterceptors>

    <mirroredQueue copyMessage="true" />    <!-- postfix=".qmirror" prefix="" -->

</destinationInterceptors>

當配置完成之後，啓動activemq服務發送queue時

public class QueueSender {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new
                ActiveMQConnectionFactory("tcp://127.0.0.1:61616");
        Connection connection = connectionFactory.createConnection();
        connection.start();
        Session session = connection.createSession(Boolean.TRUE, Session.AUTO_ACKNOWLEDGE);
        Destination destination = session.createQueue("my-queue");
        MessageProducer producer = session.createProducer(destination);
        for(int i=0; i<3; i++) {
            TextMessage message = session.createTextMessage("message--"+i);
            Thread.sleep(1000);
            //通過消息生產者發出消息
            producer.send(message);
        }
        session.commit();
        session.close();
        connection.close();
    }
}

會生成鏡像的queue的topic

所有需要接受該消息的Client只需要註冊該topic，接受消息即可

public class PersistanceReceiver2 {
    public static void main(String[] args) throws Exception {
        ConnectionFactory cf = new ActiveMQConnectionFactory("tcp://127.0.0.1:61616");
        Connection connection = cf.createConnection();
        connection.setClientID("cc1");//設置ClientID

        final Session session = connection.createSession(Boolean.TRUE, Session.AUTO_ACKNOWLEDGE);
        Topic destination = session.createTopic("VirtualTopic.Mirror.my-queue");
        //創建持久化用戶
        TopicSubscriber consumer = session.createDurableSubscriber(destination,"T1");
        connection.start();
        Message message = consumer.receive();
        while(message!=null) {
            TextMessage txtMsg = (TextMessage)message;
            session.commit();
            System.out.println("收到消 息：" + txtMsg.getText());
            message = consumer.receive(1000L);
        }
        session.close();
        connection.close();
    }
}