RabbitMQ spring boot TTL延时消费

关于延时消费主要分为两种实现，一种是rabbitmq的TTL机制，一种是rabbitmq的插件实现。

实现一：TTL

1、设置队列的过期时间
2、设置消息的过期时间

添加相关maven依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

1、设置队列过期时间实现延时消费

交换机及队列配置

代码中有四个配置，
第一个配置的exchange是用来接收已过期的队列信息并进行重新分配队列进行消费，
第二个配置的repeatTradeQueue为exchange重新分配的队列名，
第三个是将repeatTradeQueue队列与exchange交换机绑定，并指定对应的routing key，
第四个配置的就是我们要设置过期时间的队列deadLetterQueue，
配置中有三个参数，x-message-ttl为过期时间，该队列所有消息的过期时间都为配置的这个值，单位为毫秒，这里设置过期时间为3秒，x-dead-letter-exchange是指过期消息重新转发到指定交换机，也就是exchange，x-dead-letter-routing-key是该交换机上绑定的routing-key，将通过配置的routing-key分配对应的队列，也就是前面配置的repeatTradeQueue。

import java.util.HashMap;
import java.util.Map;import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;@SpringBootApplication
public class Application {//交换机用于重新分配队列@BeanDirectExchange exchange() {return new DirectExchange("exchange");}//用于延时消费的队列@Beanpublic Queue repeatTradeQueue() {Queue queue = new Queue("repeatTradeQueue",true,false,false);return queue; }//绑定交换机并指定routing key@Beanpublic Binding  repeatTradeBinding() {return BindingBuilder.bind(repeatTradeQueue()).to(exchange()).with("repeatTradeQueue");}//配置死信队列@Beanpublic Queue deadLetterQueue() {Map<String,Object> args = new HashMap<>();args.put("x-message-ttl", 3000);args.put("x-dead-letter-exchange", "exchange");args.put("x-dead-letter-routing-key", "repeatTradeQueue");return new Queue("deadLetterQueue", true, false, false, args);}public static void main(String[] args) throws Exception {SpringApplication.run(Application.class, args);}
}

配置生产者，这里生产者需要指定前面配置了过期时间的队列deadLetterQueue

import java.time.LocalDateTime;import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;@Component
public class DeadLetterSender {@Autowiredprivate AmqpTemplate rabbitTemplate;public void send(String msg) {System.out.println("DeadLetterSender 发送时间:"+LocalDateTime.now().toString()+" msg内容："+msg);rabbitTemplate.convertAndSend("deadLetterQueue", msg);}}

配置消费者，消费者监听指定用于延时消费的队列repeatTradeQueue

import java.time.LocalDateTime;@Component
@RabbitListener(queues = "repeatTradeQueue")
public class RepeatTradeReceiver {@RabbitHandlerpublic void process(String msg) {System.out.println("repeatTradeQueue 接收时间:"+LocalDateTime.now().toString()+" 接收内容:"+msg);}}

写一个简单的接口调用测试延时消费是否成功

import org.springframework.beans.factory.annotation.Autowired;@RestController
@RequestMapping("/rabbit")
public class RabbitTest {@Autowiredprivate DeadLetterSender deadLetterSender;@GetMapping("/deadTest")public void deadTest() {deadLetterSender.send("队列设置过期时间测试");}}

2、设置消息过期时间实现延时消费

先贴上配置的代码，基本配置都一样，唯一的区别是deadLetterQueue的过期时间这里不做配置，需要注意的是，因为我这里用的是同一个队列名，所以即使将队列过期时间配置删除，mq中该队列过期时间仍然还是存在的，所以需要删除该队列，启动项目时才能重新配置该队列属性，可能可以通过配置的方式重新覆盖属性配置，当然也可以保留队列过期时间的配置，当两个过期时间都存在时，消息取更小的过期时间。

import java.util.HashMap;@SpringBootApplication
public class Application {//用于死信队列转发的交换机@BeanDirectExchange exchange() {return new DirectExchange("exchange");}//用于延时消费的队列@Beanpublic Queue repeatTradeQueue() {Queue queue = new Queue("repeatTradeQueue",true,false,false);return queue; }//绑定交换机并指定routing key@Beanpublic Binding  repeatTradeBinding() {return BindingBuilder.bind(repeatTradeQueue()).to(exchange()).with("repeatTradeQueue");}//配置死信队列@Beanpublic Queue deadLetterQueue() {Map<String,Object> args = new HashMap<>();args.put("x-dead-letter-exchange", "exchange");args.put("x-dead-letter-routing-key", "repeatTradeQueue");return new Queue("deadLetterQueue", true, false, false, args);}public static void main(String[] args) throws Exception {SpringApplication.run(Application.class, args);}
}

配置生产者,message的expiration就是过期时间的设置，单位也是毫秒

import java.time.LocalDateTime;import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;@Component
public class DeadLetterSender {@Autowiredprivate AmqpTemplate rabbitTemplate;public void send(String msg, long times) {System.out.println("DeadLetterSender 发送时间:" + LocalDateTime.now().toString() + " msg内容：" + msg);MessagePostProcessor processor = new MessagePostProcessor() {@Overridepublic Message postProcessMessage(Message message) throws AmqpException {message.getMessageProperties().setExpiration(times + "");return message;}};rabbitTemplate.convertAndSend("deadLetterQueue", (Object)msg, processor);}
}

消费者不变，用之前的类即可

稍微修改一下接口，设置时间为5秒

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import me.miaobo.mq.sender.DeadLetterSender;@RestController
@RequestMapping("/rabbit")
public class RabbitTest {@Autowiredprivate DeadLetterSender deadLetterSender;@GetMapping("/deadTest")public void deadTest() {deadLetterSender.send("消息设置过期时间测试",5000);}
}