一文搞懂RabbitMQ的ack与nack

connection = factory.newConnection();      final Channel channel = connection.createChannel();channel.queueDeclare("队列名", true, false, false, null);
//第二个参数设为true为自动应答，false为手动ackchannel.basicConsume("队列名", true, new DefaultConsumer(channel){    @Override        public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {       try {          Thread.sleep(10000);          System.out.println(new String(body, "UTF-8"));        //模拟异常        int i = 1/0;        //手动ack        //channel.basicAck(envelope.getDeliveryTag(), false);       } catch (Exception e) {                //重新放入队列        //channel.basicNack(envelope.getDeliveryTag(), false, true);        //抛弃此条消息        //channel.basicNack(envelope.getDeliveryTag(), false, false);        e.printStackTrace();
      }finally {              }                    }});