Question

我试图了解带有发送方和接收方程序的RabbitMQ服务器。现在，当发送方发送单个消息并且接收方将收到相同的消息时，整个设置运行良好。

然而，当我发送两条消息（通过运行发送两次）并运行接收程序两次时，我只得到第一条消息。

发件人

  ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();


        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        String message = "He12!";
        channel.basicPublish("", QUEUE_NAME, null, message.getBytes());
        System.out.println("Sent "+message);
        channel.close();
        connection.close();

接收机

    ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("localhost");
    Connection connection = factory.newConnection();
    Channel channel = connection.createChannel();

    channel.queueDeclare(QUEUE_NAME, true, false, false, null);

    QueueingConsumer consumer = new QueueingConsumer(channel);
    channel.basicConsume(QUEUE_NAME, true, consumer);
    QueueingConsumer.Delivery delivery = consumer.nextDelivery();
    /*channel.basicCancel(consumer.getConsumerTag());   */

    String message;
     if (delivery != null) {
        message = new String(delivery.getBody());
        System.out.println("Reciever .."+message);

    }

    channel.close();
    connection.close();

Answer 1

当我使用no_Ack = false修改Receiver并调用BasicAck时，问题解决了。感谢@robthewolf和@Card（推特）提供帮助。

PFB修改后的接收器。

        ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("localhost");
    Connection connection = factory.newConnection();
    Channel channel = connection.createChannel();

    channel.queueDeclare(QUEUE_NAME, true, false, false, null);

    QueueingConsumer consumer = new QueueingConsumer(channel);
    channel.basicConsume(QUEUE_NAME, false, consumer);
    QueueingConsumer.Delivery delivery = consumer.nextDelivery(10);
    /*channel.basicCancel(consumer.getConsumerTag());   */

    String message = null;

     if (delivery != null) {
        message = new String(delivery.getBody());
        System.out.println("Reciever .."+message);
        channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
    }

    channel.close();
    connection.close();
    return message;

Answer 2

你没有

尝试过吗？

channel.basicCancel(consumer.getConsumerTag());

线？

此外，做这样的事情要好得多：

while(true){
  QueueingConsumer.Delivery delivery = consumer.nextDelivery();
  String message;
  if (delivery != null) {
    message = new String(delivery.getBody());
    System.out.println("Reciever .."+message);
  }
}

这样您只有一个消费者在循环中消费所有消息。这只是一个例子，我只是有办法彻底摆脱循环而不是必须ctrl-c。

RabbitMQ中的发送者和接收者对

2 个答案: