java - 求MQ的队列深度

Question

我想找到MQ当前的队列深度。我的程序可以在队列上读写。

我能够编写一个消费者来消费队列中的消息。我可以使用计数器来计算队列中有多少消息。但我需要找到队列深度而不丢失消息。

try {
        // Create a connection factory
        JmsFactoryFactory ff = JmsFactoryFactory.getInstance(WMQConstants.WMQ_PROVIDER);
        JmsConnectionFactory cf = ff.createConnectionFactory();

        // Set the properties
        cf.setStringProperty(WMQConstants.WMQ_HOST_NAME, HOST);
        cf.setIntProperty(WMQConstants.WMQ_PORT, PORT);
        cf.setStringProperty(WMQConstants.WMQ_CHANNEL, CHANNEL);
        cf.setIntProperty(WMQConstants.WMQ_CONNECTION_MODE, WMQConstants.WMQ_CM_CLIENT);
        cf.setStringProperty(WMQConstants.WMQ_QUEUE_MANAGER, QMGR);
        cf.setStringProperty(WMQConstants.WMQ_APPLICATIONNAME, "JmsPutGet (JMS)");
        cf.setBooleanProperty(WMQConstants.USER_AUTHENTICATION_MQCSP, true);
        cf.setStringProperty(WMQConstants.USERID, APP_USER);
        cf.setStringProperty(WMQConstants.PASSWORD, APP_PASSWORD);

        // Create JMS objects
        context = cf.createContext();
        destination = context.createQueue("queue:///" + QUEUE_NAME);

        long uniqueNumber = System.currentTimeMillis() % 1000;
        TextMessage message = context.createTextMessage("Your lucky number today is " + uniqueNumber);

        producer = context.createProducer();
        producer.send(destination, message);
        System.out.println("Sent message:\n" + message);

        consumer = context.createConsumer(destination); // autoclosable
        String receivedMessage = consumer.receiveBody(String.class, 15000); // in ms or 15 seconds

        System.out.println("\nReceived message:\n" + receivedMessage);

        recordSuccess();
    }

代码应该打印队列深度。

Answer 1

队列深度可以通过浏览消息来统计。浏览不消耗消息。

Connection connection = connectionFactory.createConnection();
connection.start();

Session session = connection.createSession(false, Session.DUPS_OK_ACKNOWLEDGE);
Queue q = session.createQueue("exampe_queue");
QueueBrowser browser = session.createBrowser(q);
Enumeration enumeration = browser.getEnumeration();

long msgCounter = 0;
while (enumeration.hasMoreElements()) {
    Message msg = (Message) enumeration.nextElement();
    msgCounter += 1;
}

System.out.println("Queue depth: " + msgCounter);

但是，当客户端从代理提取消息时，此方法非常慢。如果您需要偶尔检查队列深度以进行监控或类似目的，那么它会起作用。

更好的解决方案是使用 get-me-a-q-depth 调用，但这不是 JMS api 指定的；但是它通常存在于特定于实现的库中。