spring:
  rabbitmq:
    publisher-confirms: true
    publisher-returns: true
    template:
      mandatory: true

//publisher-confirms：设置为true时。当消息投递到Exchange后，会回调confirm()方法进行通知生产者
//publisher-returns：设置为true时。当消息匹配到Queue并且失败时，会通过回调returnedMessage()方法返回消息
//spring.rabbitmq.template.mandatory: 设置为true时。指定消息在没有被队列接收时会通过回调returnedMessage()方法退回。

@Component
public class RabbitmqConfirmCallback implements RabbitTemplate.ConfirmCallback, RabbitTemplate.ReturnCallback {
    private Logger logger = LoggerFactory.getLogger(RabbitmqConfirmCallback.class);

    /**
     * 监听消息是否到达Exchange
     *
     * @param correlationData 包含消息的唯一标识的对象
     * @param ack             true 标识 ack，false 标识 nack
     * @param cause           nack 投递失败的原因
     */
    @Override
    public void confirm(CorrelationData correlationData, boolean ack, String cause) {
        if (ack) {
            logger.info("消息投递成功~消息Id：{}", correlationData.getId());
        } else {
            logger.error("消息投递失败，Id：{}，错误提示：{}", correlationData.getId(), cause);
        }
    }

    @Override
    public void returnedMessage(Message message, int replyCode, String replyText, String exchange, String routingKey) {
        logger.info("消息没有路由到队列，获得返回的消息");
        Map map = byteToObject(message.getBody(), Map.class);
        logger.info("message body: {}", map == null ? "" : map.toString());
        logger.info("replyCode: {}", replyCode);
        logger.info("replyText: {}", replyText);
        logger.info("exchange: {}", exchange);
        logger.info("routingKey: {}", exchange);
        logger.info("------------> end <------------");
    }

    @SuppressWarnings("unchecked")
    private <T> T byteToObject(byte[] bytes, Class<T> clazz) {
        T t;
        try (ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
             ObjectInputStream ois = new ObjectInputStream(bis)) {
            t = (T) ois.readObject();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return t;
    }
}

@Service
public class RabbitMQServiceImpl implements RabbitMQService {
 @Resource
    private RabbitmqConfirmCallback rabbitmqConfirmCallback;

    @Resource
    private RabbitTemplate rabbitTemplate;

    @PostConstruct
    public void init() {
        //指定 ConfirmCallback
        rabbitTemplate.setConfirmCallback(rabbitmqConfirmCallback);
        //指定 ReturnCallback
        rabbitTemplate.setReturnCallback(rabbitmqConfirmCallback);
    }
    
    @Override
    public String sendMsg(String msg) throws Exception {
        Map<String, Object> message = getMessage(msg);
        try {
            CorrelationData correlationData = (CorrelationData) message.remove("correlationData");
            rabbitTemplate.convertAndSend(RabbitMQConfig.RABBITMQ_DEMO_DIRECT_EXCHANGE, RabbitMQConfig.RABBITMQ_DEMO_DIRECT_ROUTING, message, correlationData);
            return "ok";
        } catch (Exception e) {
            e.printStackTrace();
            return "error";
        }
    }
    
 private Map<String, Object> getMessage(String msg) {
        String msgId = UUID.randomUUID().toString().replace("-", "").substring(0, 32);
        CorrelationData correlationData = new CorrelationData(msgId);
        String sendTime = sdf.format(new Date());
        Map<String, Object> map = new HashMap<>();
        map.put("msgId", msgId);
        map.put("sendTime", sendTime);
        map.put("msg", msg);
        map.put("correlationData", correlationData);
        return map;
    }
}

@Bean
    public DirectExchange rabbitmqDemoDirectExchange() {
        //Direct交换机
        return new DirectExchange(RabbitMQConfig.RABBITMQ_DEMO_DIRECT_EXCHANGE, true, false);
    }

 @Bean
    public Queue fanoutExchangeQueueA() {
     //只需要指定名称，默认是持久化的
        return new Queue(RabbitMQConfig.FANOUT_EXCHANGE_QUEUE_TOPIC_A);
    }

spring:
  rabbitmq:
    listener:
      simple:
  acknowledge-mode: manual # 手动ack模式
        concurrency: 1 # 最少消费者数量
        max-concurrency: 10 # 最大消费者数量

@Component
public class RabbitDemoConsumer {

    enum Action {
        //处理成功
        SUCCESS,
        //可以重试的错误，消息重回队列
        RETRY,
        //无需重试的错误，拒绝消息，并从队列中删除
        REJECT
    }

    @RabbitHandler
    @RabbitListener(queuesToDeclare = @Queue(RabbitMQConfig.RABBITMQ_DEMO_TOPIC))
    public void process(String msg, Message message, Channel channel) {
        long tag = message.getMessageProperties().getDeliveryTag();
        Action action = Action.SUCCESS;
        try {
            System.out.println("消费者RabbitDemoConsumer从RabbitMQ服务端消费消息：" + msg);
            if ("bad".equals(msg)) {
                throw new IllegalArgumentException("测试：抛出可重回队列的异常");
            }
            if ("error".equals(msg)) {
                throw new Exception("测试：抛出无需重回队列的异常");
            }
        } catch (IllegalArgumentException e1) {
            e1.printStackTrace();
            //根据异常的类型判断，设置action是可重试的，还是无需重试的
            action = Action.RETRY;
        } catch (Exception e2) {
            //打印异常
            e2.printStackTrace();
            //根据异常的类型判断，设置action是可重试的，还是无需重试的
            action = Action.REJECT;
        } finally {
            try {
                if (action == Action.SUCCESS) {
                    //multiple 表示是否批量处理。true表示批量ack处理小于tag的所有消息。false则处理当前消息
                    channel.basicAck(tag, false);
                } else if (action == Action.RETRY) {
                    //Nack，拒绝策略，消息重回队列
                    channel.basicNack(tag, false, true);
                } else {
                    //Nack，拒绝策略，并且从队列中删除
                    channel.basicNack(tag, false, false);
                }
                channel.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}