RabbitMQ 死信 exchange/queue

Question

我不太明白死信exchange/queue。在线文档说：

republished to another exchange when any of the following events occur:
    The message is rejected (basic.reject or basic.nack) with requeue=false,
    The TTL for the message expires; or
    The queue length limit is exceeded.

这是否意味着当这些事件发生时，消息将自动移至死信队列？或者我必须在我的代码中专门将那些 'dead' 消息移动到那个 DLQ？

另外，如何为我的普通队列设置 DLX/DLQ？说当我的正常队列 failed/expired 中有消息时，它会移动到 DLX/DLQ?

Answer 1

这是一个完整的例子：

public class DXtest {
    public static void main(String[] argv)
            throws IOException,
            InterruptedException, TimeoutException {

        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");

        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        channel.exchangeDeclare("my.exchange", "fanout");

        Map<String, Object> args = new HashMap<String, Object>();
        args.put("x-dead-letter-exchange", "my.exchange");
        args.put("x-max-length", 2);
        channel.queueDeclare("myqueue", false, false, false, args); // here you setup your queue, 
//for example with x-max-length, when the limit is reach, the message head message queue will be redirect  
//to the my.exchange and then to my-dead-letter-queue



        channel.queueDeclare("my-dead-letter-queue", false, false, false, null);
        channel.queueBind("my-dead-letter-queue","my.exchange","");


        Consumer consumer = new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body)
                    throws IOException {
                String message = new String(body, "UTF-8");
                System.out.println(" [x] Message   '" + message + "'" + new Date());
            }
        };
        channel.basicConsume("my-dead-letter-queue", true, consumer);

    }

}

RabbitMQ 死信 exchange/queue

RabbitMQ dead letter exchange/queue

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