如何正确接收来自队列 IBM MQ 的消息

Question

这段代码应该从队列中读取，如果队列为空，则通过定时器重复读取检查Text或Byte的格式。用这种格式检查空队列是否正确？在这种情况下计时器会工作吗？由于未配置MQ队列，目前无法查看。

public class Main {
    public static void main(String[] args) {
boolean tru = true;

        try {
            /*MQ Конфигурация подключения*/
            MQQueueConnectionFactory mqQueueConnectionFactory = new MQQueueConnectionFactory();
            mqQueueConnectionFactory.setHostName("localhost");
            mqQueueConnectionFactory.setChannel("SVRCONN");
            mqQueueConnectionFactory.setPort(1414);
            mqQueueConnectionFactory.setIntProperty(WMQConstants.WMQ_CONNECTION_MODE, WMQConstants.WMQ_CM_CLIENT);
            mqQueueConnectionFactory.setQueueManager("MQ_APPLE");
            mqQueueConnectionFactory.setTransportType(JMSC.MQJMS_TP_CLIENT_MQ_TCPIP);
            QueueConnection queueConnection = mqQueueConnectionFactory.createQueueConnection("name", "pass");
            MQQueueSession session = (MQQueueSession) queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
            MQQueue queue = (MQQueue) session.createQueue("queue:///Q1");
            MQQueueReceiver receiver = (MQQueueReceiver) session.createReceiver(queue);
            queueConnection.start();

          while(tru){
              TextMessage receivedMessage = (TextMessage) receiver.receive();
              if(receivedMessage != null){
                  MStart(receivedMessage);
                  tru = false;
              } else {
                  Timer timer = new Timer(10000,new ActionListener() {
                      public void actionPerformed(ActionEvent arg0) {
                          System.out.println("Timer Run");
                      }
                  });
                  timer.start();
              }
          }

            receiver.close();
            session.close();
            queueConnection.close();

        } catch (JMSException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void MStart(TextMessage receivedMessage) throws JMSException {
            if (receivedMessage instanceof BytesMessage) {
                TextMessage textMessage = (TextMessage) receivedMessage;
                System.out.println("Received message '"
                        + textMessage.getText() + "'");
            } else if (receivedMessage instanceof TextMessage) {
                System.out.println("Received message: " + receivedMessage.getText());
            }
    }
}

Answer 1

请注意，您的 receiver.receive(); 调用将无限期阻塞。来自 MQMessageConsumer 文档：

Receives the next message produced for this message consumer. This call blocks indefinitely until a message is produced or until this message consumer is closed.

如果您想在指定的时间内从队列中读取数据，也许您最好使用 receive(long timeout) 方法：

public javax.jms.Message receive(long timeout) throws javax.jms.JMSException

Receives the next message that arrives within the specified timeout interval. This call blocks until a message arrives, the timeout expires, or this message consumer is closed. A timeout of zero never expires, and the call blocks indefinitely.

Answer 2

除非需要使用计时器，否则我更喜欢使用receive(timeout)。如果队列中有消息，则接收调用将 return 接收消息，否则它将超时并抛出 2033 原因代码异常。您可以捕获此异常并再次调用接收以等待消息。这也将允许您在被要求时停止此线程。

而不是 (TextMessage) receiver.receive() 只需执行 Message msg = receiver.receive() 然后使用 if(msg instanceof TextMessage) 确定收到的消息类型。

如何正确接收来自队列 IBM MQ 的消息

How to correctly receive a message from the queue IBM MQ

java

jms

ibm-mq