Rabbitmq的死信队列和延时队列

Rabbitmq的死信队列和延时队列
一、死信队列
死信队列其实和普通的队列没啥大的区别，都需要创建自己的Queue、Exchange,然后通过RoutingKey绑定到Exchange上去，只不过死信队列的RoutingKey和Exchange要作为参数，绑定到正常的队列上去，一种应用场景是正常队列里面的消息被basicNack或者reject时，消息就会被路由到正常队列绑定的死信队列中，还有一种还有常用的场景就是开启了自动签收，然后消费者消费消息时出现异常，超过了重试次数，那么这条消息也会进入死信队列，如果配置了话，当然还有其他的应用场景，这里不一一讨论。

1.1、死信队列和交换器配置
这里有两个队列，正常的业务队列emailQueue和与之绑定的死信队列，这里只演示，手动签收，消费者捕获异常Nack

1.1.2、yml配置
spring:
rabbitmq:
host: 192.168.99.12
port: 5672
username: guest
password: guest
# 发送确认
publisher-confirms: true
# 路由失败回调
publisher-returns: true
template:
# 必须设置成true 消息路由失败通知监听者，false 将消息丢弃
mandatory: true
listener:
simple:
# 每次从RabbitMQ获取的消息数量
prefetch: 1
default-requeue-rejected: false
# 每个队列启动的消费者数量
concurrency: 1
# 每个队列最大的消费者数量
max-concurrency: 1
# 签收模式为手动签收-那么需要在代码中手动ACK
acknowledge-mode: manual
#邮件队列
email:
queue:
name: demo.email

#邮件交换器名称
exchange:
name: demoTopicExchange

#死信队列
dead:
letter:
queue:
name: demo.dead.letter
exchange:
name: demoDeadLetterTopicExchange
1.1.3、死信队列配置
/**

• rabbitmq 配置

• @author DUCHONG

• @since 2020-08-23 14:05
  **/
  @Configuration
  @Slf4j
  public class RabbitmqConfig {

  @Value("$email.queue.name")privateStringemailQueue;@Value("${exchange.name}")
  private String topicExchange;
  @Value("$dead.letter.queue.name")privateStringdeadLetterQueue;@Value("${dead.letter.exchange.name}")
  private String deadLetterExchange;

  @Bean
  public Queue emailQueue() {

   Map<String, Object> arguments = new HashMap<>(2);
   // 绑定死信交换机
   arguments.put("x-dead-letter-exchange", deadLetterExchange);
   // 绑定死信的路由key
   arguments.put("x-dead-letter-routing-key", deadLetterQueue+".#");
  
   return new Queue(emailQueue,true,false,false,arguments);
  

  }

  @Bean
  TopicExchange emailExchange() {
  return new TopicExchange(topicExchange);
  }

  @Bean
  Binding bindingEmailQueue() {
  return BindingBuilder.bind(emailQueue()).to(emailExchange()).with(emailQueue+".#");
  }

  //私信队列和交换器
  @Bean
  public Queue deadLetterQueue() {
  return new Queue(deadLetterQueue);
  }

  @Bean
  TopicExchange deadLetterExchange() {
  return new TopicExchange(deadLetterExchange);
  }

  @Bean
  Binding bindingDeadLetterQueue() {
  return BindingBuilder.bind(deadLetterQueue()).to(deadLetterExchange()).with(deadLetterQueue+".#");
  }

}
1.2、消息发送方
@Configuration
@EnableScheduling
@Slf4j
public class ScheduleController {

@Autowired
RabbitTemplate rabbitTemplate;

@Value("${exchange.name}")
private String topicExchange;

@Scheduled(cron = "0 0/2 * * * ?")
public void sendEmailMessage() {

    String msg = RandomStringUtils.randomAlphanumeric(8);
    JSONObject email=new JSONObject();
    email.put("content",msg);
    email.put("to","duchong@qq.com");
    CorrelationData correlationData=new CorrelationData(UUID.randomUUID().toString());
    rabbitTemplate.convertAndSend(topicExchange,"demo.email.x",email.toJSONString(),correlationData);
    log.info("---发送 email 消息---{}---messageId---{}",email,correlationData.getId());
}

}
1.3、消息消费方
@Component
@Slf4j
public class MessageHandler {

/**
* 邮件消费者
* @param message
* @param channel
* @param headers
* @throws IOException
*/
@RabbitListener(queues =“demo.email”)
@RabbitHandler
public void handleEmailMessage(Message message, Channel channel, @Headers Map<String,Object> headers) throws IOException {

    try {

        String msg=new String(message.getBody(), CharEncoding.UTF_8);
        JSONObject jsonObject = JSON.parseObject(msg);
        jsonObject.put("messageId",headers.get("spring_returned_message_correlation"));
        log.info("---接受到消息---{}",jsonObject);
		//主动异常
		int m=1/0;
        //手动签收
        channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
    }
    catch (Exception e) {
        log.info("handleEmailMessage捕获到异常,拒绝重新入队---消息ID---{}",headers.get("spring_returned_message_correlation"));
        //异常，ture 重新入队,或者false,进入死信队列
        channel.basicNack(message.getMessageProperties().getDeliveryTag(),false,false);

    }
}

/**
 * 死信消费者，自动签收开启状态下，超过重试次数，或者手动签收，reject或者Nack
 * @param message
 */
@RabbitListener(queues = "demo.dead.letter")
public void handleDeadLetterMessage(Message message, Channel channel,@Headers Map<String,Object> headers) throws IOException {

    //可以考虑数据库记录，每次进来查数量，达到一定的数量，进行预警，人工介入处理
    log.info("接收到死信消息:---{}---消息ID---{}", new String(message.getBody()),headers.get("spring_returned_message_correlation"));
	//回复ack
    channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
}

}

1.4、结果
image-20200823185649078

二、延时队列
延时队列顾名思义，不是及时的队列，也就是发送者发给的消息要延时一段时间，消费者才能接受的到，这里有个典型的应用场景就是订单30分钟内未支付就关闭订单，当然死信队列也是可以实现的，这里只演示消息的延时消费逻辑，订单逻辑就一个判断，这里不做讨论。

2.1、延时队列和交换器配置
使用延时队列之前，需要先安装延时队列插件，安装方法，前面已经介绍过了，这里放个链接

延时队列插件安装

2.1.1、yml配置
spring:
rabbitmq:
host: 192.168.99.12
port: 5672
username: guest
password: guest
# 发送确认
publisher-confirms: true
# 路由失败回调
publisher-returns: true
template:
# 必须设置成true 消息路由失败通知监听者，false 将消息丢弃
mandatory: true
#消费端
listener:
simple:
# 每次从RabbitMQ获取的消息数量
prefetch: 1
default-requeue-rejected: false
# 每个队列启动的消费者数量
concurrency: 1
# 每个队列最大的消费者数量
max-concurrency: 1
# 签收模式为手动签收-那么需要在代码中手动ACK
acknowledge-mode: manual
#邮件队列
email:
queue:
name: demo.email

#邮件交换器名称
exchange:
name: demoTopicExchange

#死信队列
dead:
letter:
queue:
name: demo.dead.letter
exchange:
name: demoDeadLetterTopicExchange

#延时队列
delay:
queue:
name: demo.delay
exchange:
name: demoDelayTopicExchange
2.1.2、延时队列配置
/**

• rabbitmq 配置

• @author DUCHONG

• @since 2020-08-23 14:05
  **/
  @Configuration
  @Slf4j
  public class RabbitmqConfig {

  @Value("$email.queue.name")privateStringemailQueue;@Value("${exchange.name}")
  private String topicExchange;
  @Value("$dead.letter.queue.name")privateStringdeadLetterQueue;@Value("${dead.letter.exchange.name}")
  private String deadLetterExchange;
  @Value("$delay.queue.name")privateStringdelayQueue;@Value("${delay.exchange.name}")
  private String delayExchange;

  @Bean
  public Queue emailQueue() {

   Map<String, Object> arguments = new HashMap<>(2);
   // 绑定死信交换机
   arguments.put("x-dead-letter-exchange", deadLetterExchange);
   // 绑定死信的路由key
   arguments.put("x-dead-letter-routing-key", deadLetterQueue+".#");
  
   return new Queue(emailQueue,true,false,false,arguments);
  

  }

  @Bean
  TopicExchange emailExchange() {
  return new TopicExchange(topicExchange);
  }

  @Bean
  Binding bindingEmailQueue() {
  return BindingBuilder.bind(emailQueue()).to(emailExchange()).with(emailQueue+".#");
  }

  //私信队列和交换器
  @Bean
  public Queue deadLetterQueue() {
  return new Queue(deadLetterQueue);
  }

  @Bean
  TopicExchange deadLetterExchange() {
  return new TopicExchange(deadLetterExchange);
  }

  @Bean
  Binding bindingDeadLetterQueue() {
  return BindingBuilder.bind(deadLetterQueue()).to(deadLetterExchange()).with(deadLetterQueue+".#");
  }
  //延时队列
  @Bean
  public Queue delayQueue() {
  return new Queue(delayQueue);
  }

  @Bean
  CustomExchange delayExchange() {
  Map<String, Object> args = new HashMap<>();
  args.put(“x-delayed-type”, “topic”);
  //参数二为类型：必须是x-delayed-message
  return new CustomExchange(delayExchange, “x-delayed-message”, true, false, args);

  }

  @Bean
  Binding bindingDelayQueue() {
  return BindingBuilder.bind(delayQueue()).to(delayExchange()).with(delayQueue+".#").noargs();
  }
  }
  2.2、消息发送方
  30分钟时间太久了，这里延时2分钟来看效果

@Configuration
@EnableScheduling
@Slf4j
public class ScheduleController {

@Autowired
RabbitTemplate rabbitTemplate;

@Value("${exchange.name}")
private String topicExchange;

@Value("${delay.exchange.name}")
private String delayTopicExchange;

@Scheduled(cron = "0 0/1 * * * ?")
public void sendEmailMessage() {

    String msg = RandomStringUtils.randomAlphanumeric(8);
    JSONObject email=new JSONObject();
    email.put("content",msg);
    email.put("to","duchong@qq.com");
    CorrelationData correlationData=new CorrelationData(UUID.randomUUID().toString());
    rabbitTemplate.convertAndSend(topicExchange,"demo.email.x",email.toJSONString(),correlationData);
    log.info("---发送 email 消息---{}---messageId---{}",email,correlationData.getId());
}


@Scheduled(cron = "0 0/1 * * * ?")
public void sendDelayOrderMessage() throws Exception{

    //订单号 id实际是保存订单后返回的，这里用uuid代替
    String orderId = UUID.randomUUID().toString();
    // 模拟订单信息
    JSONObject order=new JSONObject();
    order.put("orderId",orderId);
    order.put("goodsName","vip充值");
    order.put("orderAmount","99.00");
    CorrelationData correlationData=new CorrelationData(orderId);
    MessageProperties messageProperties = new MessageProperties();
    messageProperties.setMessageId(orderId);
    //30分钟时间太长，这里延时120s消费
    messageProperties.setHeader("x-delay", 120000);
    Message message = new Message(order.toJSONString().getBytes(CharEncoding.UTF_8), messageProperties);

    rabbitTemplate.convertAndSend(delayTopicExchange,"demo.delay.x",message,correlationData);

    log.info("---发送 order 消息---{}---orderId---{}",order,correlationData.getId());
    //睡一会，为了看延迟效果
    TimeUnit.MINUTES.sleep(10);
}

}
2.3、消息消费方
@Component
@Slf4j
public class MessageHandler {

/**
 * 邮件发送
 * @param message
 * @param channel
 * @param headers
 * @throws IOException
 */
@RabbitListener(queues ="demo.email")
@RabbitHandler
public void handleEmailMessage(Message message, Channel channel, @Headers Map<String,Object> headers) throws IOException {

    try {

        String msg=new String(message.getBody(), CharEncoding.UTF_8);
        JSONObject jsonObject = JSON.parseObject(msg);
        jsonObject.put("messageId",headers.get("spring_returned_message_correlation"));
        log.info("---接受到消息---{}",jsonObject);
		//主动异常
		int m=1/0;
        //手动签收
        channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
    }
    catch (Exception e) {
        log.info("handleEmailMessage捕获到异常,拒绝重新入队---消息ID---{}", headers.get("spring_returned_message_correlation"));
        //异常，ture 重新入队,或者false,进入死信队列
        channel.basicNack(message.getMessageProperties().getDeliveryTag(),false,false);

    }
}

/**
 * 死信消费者，自动签收开启状态下，超过重试次数，或者手动签收，reject或者Nack
 * @param message
 */
@RabbitListener(queues = "demo.dead.letter")
public void handleDeadLetterMessage(Message message, Channel channel,@Headers Map<String,Object> headers) throws IOException {

    //可以考虑数据库记录，每次进来查数量，达到一定的数量，进行预警，人工介入处理
    log.info("接收到死信消息:---{}---消息ID---{}", new String(message.getBody()),headers.get("spring_returned_message_correlation"));
	//回复ack
    channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
}

/**
 * 延时队列消费
 * @param message
 * @param channel
 * @param headers
 * @throws IOException
 */
@RabbitListener(queues ="demo.delay")
@RabbitHandler
public void handleOrderDelayMessage(Message message, Channel channel, @Headers Map<String,Object> headers) throws IOException {

    try {

        String msg=new String(message.getBody(), CharEncoding.UTF_8);
        JSONObject jsonObject = JSON.parseObject(msg);
        log.info("---接受到订单消息---orderId---{}",message.getMessageProperties().getMessageId());
        log.info("---订单信息---order---{}",jsonObject);
        //业务逻辑，根据订单id获取订单信息，如果还未支付，设置关闭状态，如果已支付，不做任何处理
        //手动签收
        channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
    }
    catch (Exception e) {
        log.info("handleOrderDelayMessage捕获到异常,重新入队---orderId---{}", headers.get("spring_returned_message_correlation"));
        //异常，ture 重新入队,或者false,进入死信队列
        channel.basicNack(message.getMessageProperties().getDeliveryTag(),false,true);

    }
}

}
2.4、结果

运行结果显示，同一个订单号的消息，发送过后2分钟，消费者才接受到，符合预期。