java spring rabbit - 优雅地拒绝消息

Question

I have the following listener method:

@Override
public void onMessage(Message message, Channel channel) {
  try {
    // do something bad :)
  } catch (Exception e){
    try {
      long dt = null != message.getMessageProperties() 
          ? message.getMessageProperties().getDeliveryTag() 
          : 0;
      channel.basicReject(dt, true);
    } catch(IOException io) {
      logger.error("IO-COMMON", io);
    }
  }
}

The issue is basic reject doesn't work, I don't know why. How to reject it gracefully? I think that if I reject a message, it should be requeued and reside is sth like cache, before going to next worker. But in fact this message just seems to be lost.

Answer 1

You need to set the acknowledgemode to MANUAL if you are doing your own acks. I am not sure why it's not working for you; DEBUG/TRACE logging might help.

You should consider letting the container handle the acks - use acknowledgemode=AUTO ; the container will normally requeue the message for any exception thrown or ack it if the listener returns normally.

You can set defaultRequeueRejected to false (it is true by default) and the message will be discarded (or routed to a DLX/DLQ).

You can also throw an AmqpRejectAndDontRequeueException to override the default mechanism of requeuing failed messages.

If the ack mode is NONE - there are no acks and RabbitMQ automatically acks the message as soon as it's sent.