简介
RabbitMQ 的延时队列(Delayed Queue)是指消息在发送到队列后,会在一定的时间内被延迟处理,直到预设的延迟时间结束,消息才会被消费者消费。RabbitMQ 本身并不原生支持延时队列,但我们可以通过一些插件或特定配置来实现这种功能。
延时队列的应用场景
- 定时任务:比如定时发送邮件、推送通知等操作。
- 重试机制:当某些任务失败时,可以让任务在一段时间后再次尝试。
- 延迟消费:在特定时间后消费消息,而不是立即消费。
死信队列(Dead Letter Queue,简称 DLQ)是消息队列中的一个特殊队列,用于存放那些因某些原因无法被正常消费的消息。死信队列在许多消息队列系统(如 RabbitMQ、Kafka 等)中都有应用。通过将无法消费的消息转移到死信队列中,可以帮助开发者发现和处理消息消费过程中的异常或错误。
死信队列的主要用途是:
- 错误处理:用于捕获无法消费的消息,避免这些消息丢失,并提供后续人工干预或自动重试的机会。
- 监控和诊断:通过查看死信队列,可以帮助开发者快速发现问题,例如队列被溢出、消息格式不正确等。
- 防止数据丢失:将那些因为超时、队列溢出、消费失败等原因无法处理的消息放入死信队列,可以保证它们不会丢失,后续可以进一步调查和处理。
本文结合延时队列和死信队列,延时队列的消息设置过期时间,在时间过期之后,将消息内容推送到死信队列中进行处理。
整合逻辑
依赖
xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.30</version>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>5.8.27</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
<version>2.7.7</version>
</dependency>
配置
yaml
server:
port: 8081
spring:
application:
name: walker-rabbitmq
rabbitmq:
host: 127.0.0.1
port: 5672
username: guest_walker
password: guest
创建交换机|队列
延时队列
java
package com.walker.rabbitmq.delay.config;
import com.walker.rabbitmq.delay.constants.BaseConstant;
import com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum;
import org.springframework.amqp.core.*;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.HashMap;
import java.util.Map;
@Configuration
public class OrderDelayRabbitConfig {
// 交换机
@Bean
public DirectExchange orderDelayExchange(){
return new DirectExchange(RabbitMqConfigEnum.ORDER_DELAY.getExchange());
}
// 队列
@Bean
public Queue orderDelayQueue(){
Map<String,Object> args = new HashMap<>();
// 延时队列,需要绑定死信队列,在ttl到期之后,将队列转到死信队列
args.put(BaseConstant.xDeadLetterExchange,RabbitMqConfigEnum.ORDER_DEAD.getExchange());
args.put(BaseConstant.xDeadLetterRoutingKey,RabbitMqConfigEnum.ORDER_DEAD.getRoutingKey());
return QueueBuilder.durable(RabbitMqConfigEnum.ORDER_DELAY.getQueue()).autoDelete().withArguments(args).build();
}
//
@Bean
public Binding orderDelayQueueBinding(){
return BindingBuilder.bind(orderDelayQueue()).to(orderDelayExchange()).with(RabbitMqConfigEnum.ORDER_DELAY.getRoutingKey());
}
}
死信队列
java
package com.walker.rabbitmq.delay.config;
import com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum;
import org.springframework.amqp.core.*;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class OrderDeadRabbitConfig {
// 交换机
@Bean
public DirectExchange orderDeadExchange(){
return new DirectExchange(RabbitMqConfigEnum.ORDER_DEAD.getExchange());
}
// 队列
@Bean
public Queue orderDeadQueue(){
return QueueBuilder.durable(RabbitMqConfigEnum.ORDER_DEAD.getQueue()).autoDelete().build();
}
// 交换机、队列、路由键绑定
@Bean
public Binding orderDeadQueueBinding(){
return BindingBuilder.bind(orderDeadQueue()).to(orderDeadExchange())
.with(RabbitMqConfigEnum.ORDER_DEAD.getRoutingKey());
}
}
常量
java
package com.walker.rabbitmq.delay.constants;
import com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum;
public interface BaseConstant {
String xDeadLetterExchange = "x-dead-letter-exchange";
String xDeadLetterRoutingKey = "x-dead-letter-routing-key";
}
相关枚举
java
package com.walker.rabbitmq.delay.enums;
import lombok.AllArgsConstructor;
import lombok.Getter;
@AllArgsConstructor
@Getter
public enum RabbitMqConfigEnum {
ORDER_DELAY("direct","订单延时队列","order_delay_exchange", "order_delay_queue", "order_delay_routing_key",true),
ORDER_DEAD("direct","订单死信队列","order_dead_exchange", "order_dead_queue", "order_dead_routing_key",true);
private final String type;
private final String title;
private final String exchange;
private final String queue;
private final String routingKey;
private final Boolean durable;
}
rabbitmq工具类封装
java
package com.walker.rabbitmq.delay.service;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.json.JSONUtil;
import com.rabbitmq.client.Channel;
import com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum;
import lombok.extern.slf4j.Slf4j;
import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.stereotype.Component;
import javax.annotation.Resource;
import java.io.IOException;
import java.util.function.Consumer;
import java.util.function.Function;
@Component
@Slf4j
public class RabbitmqService {
@Resource
private RabbitTemplate rabbitTemplate;
/**
* author:walker
* time: 2024/12/30
* description: 无返回结果的手动处理方式
*/
public void doWithManualAck(String event, Message message, Channel channel, Consumer<String> method) {
String data = new String(message.getBody());
try {
method.accept(data);
sendAck(message, channel);
} catch (Exception e) {
log.error("处理事件[{}]异常数据为:{},原因如下:",event,data, e);
sendNack(message, channel);
}
}
/**
* author:walker
* time: 2024/12/30
* description: 根据返回的布尔类型,进行确认和拒绝
*/
public void doWithManualAck(String event, Message message, Channel channel, Function<String,Boolean> method) {
String data = new String(message.getBody());
try {
Boolean res = method.apply(data);
if(BooleanUtil.isTrue(res)){
sendAck(message, channel);
}else{
sendNack(message, channel);
}
} catch (Exception e) {
log.error("处理事件[{}]异常数据为:{},原因如下:",event,data, e);
sendNack(message, channel);
}
}
// 确认消息
public void sendAck(Message message, Channel channel) throws IOException {
channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
}
// 拒绝消息
public void sendNack(Message message, Channel channel) {
try {
channel.basicNack(message.getMessageProperties().getDeliveryTag(), false, true);
} catch (IOException e) {
log.error("消息消费失败,消息ID:{}", message.getMessageProperties().getMessageId(), e);
}
}
public <T> void sendDelayMsg(RabbitMqConfigEnum configEnum, T data, Integer delayTime) {
rabbitTemplate.convertAndSend(configEnum.getExchange(), configEnum.getRoutingKey(),
JSONUtil.toJsonStr(data), new MessagePostProcessor() {
@Override
public Message postProcessMessage(Message message) throws AmqpException {
message.getMessageProperties().setExpiration(String.valueOf(delayTime));
return message;
}
});
}
}
案例
实体类
java
package com.walker.rabbitmq.delay.entity;
import lombok.Data;
@Data
public class OrderInfo {
private String productName;
private Integer num;
private String userName;
private String orderTime;
}
controller 创建订单
java
package com.walker.rabbitmq.delay.controller;
import com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum;
import com.walker.rabbitmq.delay.entity.OrderInfo;
import com.walker.rabbitmq.delay.service.RabbitmqService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.Date;
@Slf4j
@RestController
@RequestMapping("/order")
public class OrderController {
@Resource
private RabbitmqService rabbitmqService;
/**
* author:walker
* time: 2025/1/2
* description: 下单
*/
@GetMapping("/create")
public void createOrder() {
OrderInfo orderInfo = new OrderInfo();
orderInfo.setProductName("羽毛球");
orderInfo.setUserName("张三");
orderInfo.setOrderTime("2025-01-02 12:00:00");
orderInfo.setNum(1);
log.info("发送消息时间{}",new Date());
rabbitmqService.sendDelayMsg(RabbitMqConfigEnum.ORDER_DELAY,orderInfo,10000);
}
}
消费者监听消息
消费者接口
java
package com.walker.rabbitmq.delay.service;
public interface IRabbitCosumerHandler {
Boolean handle(String message);
}
消费者监听方法
java
package com.walker.rabbitmq.delay.listener;
import com.rabbitmq.client.Channel;
import com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum;
import com.walker.rabbitmq.delay.constants.BaseConstant;
import com.walker.rabbitmq.delay.service.IRabbitCosumerHandler;
import com.walker.rabbitmq.delay.service.RabbitmqService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;
import javax.annotation.Resource;
import java.io.IOException;
import java.util.Date;
@Slf4j
@Component
public class OrderDeadLetterQueueConsumer implements IRabbitCosumerHandler {
@Resource
private RabbitmqService rabbitmqService;
@RabbitListener(queues = "#{T(com.walker.rabbitmq.delay.enums.RabbitMqConfigEnum).ORDER_DEAD.getQueue()}",ackMode = "MANUAL")
public void receive(Message message, Channel channel) throws IOException {
log.info("接受消息时间 {}",new Date());
String msg = new String(message.getBody());
log.info("当前时间:{},队列{}收到消息:{}", new Date().toString(),RabbitMqConfigEnum.ORDER_DEAD.getQueue(), msg);
rabbitmqService.doWithManualAck(RabbitMqConfigEnum.ORDER_DEAD.getTitle(), message, channel, this::handle);
}
@Override
public Boolean handle(String message) {
// 处理逻辑
log.info("进行订单取消的操作");
return true;
}
}