RabbitMQ延时队列的两种实现方式

# 1. 拉取带管理界面的镜像
docker pull rabbitmq:3.11-management

# 2. 启动容器并启用插件
docker run -d \
  --name rabbitmq \
  -p 5672:5672 \
  -p 15672:15672 \
  -e RABBITMQ_DEFAULT_USER=admin \
  -e RABBITMQ_DEFAULT_PASS=password \
  rabbitmq:3.11-management \
  bash -c "rabbitmq-plugins enable rabbitmq_delayed_message_exchange && rabbitmq-server"

3、为已运行的容器安装

bash 复制代码

# 1. 进入正在运行的容器
docker exec -it rabbitmq /bin/bash

# 2. 在容器内执行插件安装
rabbitmq-plugins enable rabbitmq_delayed_message_exchange

# 3. 退出容器
exit

# 4. 重启容器使插件生效
docker restart rabbitmq

4、验证安装

bash 复制代码

# 方法1：检查插件列表
docker exec rabbitmq rabbitmq-plugins list | grep delayed

# 方法2：登录管理界面
# 访问 http://localhost:15672 (使用设置的账号密码登录)
# 在 "Exchanges" 标签页创建交换机时，Type 下拉框会出现 "x-delayed-message" 选项

5、代码编写

1. 配置类

java 复制代码

@Configuration
public class RabbitMqConfig {
    
    public static final String DELAYED_EXCHANGE = "delayed.exchange";
    public static final String DELAYED_QUEUE = "delayed.queue";
    public static final String DELAYED_ROUTING_KEY = "delayed_routing_key";
 
    @Bean
    public CustomExchange delayedExchange() {
        Map<String, Object> args = new HashMap<>();
        args.put("x-delayed-type", "direct"); // 交换机类型
        return new CustomExchange(
                DELAYED_EXCHANGE,
                "x-delayed-message", // 固定类型
                true,
                false,
                args
        );
    }

    @Bean
    public Queue delayedQueue() {
        return new Queue(DELAYED_QUEUE, true);
    }

    @Bean
    public Binding delayedBinding(Queue delayedQueue, 
                                  CustomExchange delayedExchange) {
        return BindingBuilder.bind(delayedQueue)
                .to(delayedExchange)
                .with(DELAYED_ROUTING_KEY)
                .noargs();
    }
    
}

2. 生产者

java 复制代码

public void send(String exchange, String routing_key,
                 Object data, Integer delayMillis) {
    // 消息后处理器：设置延时和持久化
    MessagePostProcessor processor = message -> {
        // 毫秒
        message.getMessageProperties().setDelay(delayMillis);
        // 持久化
        message.getMessageProperties().setDeliveryMode(MessageDeliveryMode.PERSISTENT);
        return message;
    };

    rabbitTemplate.convertAndSend(exchange, routingKey, data, processor);
}

3. 消费者

java 复制代码

@Component
@RabbitListener(queues = RabbitMqConfig.DELAYED_QUEUE)
public class DelayedListener {

    @RabbitHandler
    public void listener(String data, Channel channel, Message message) {
        log.warn("消息消费成功，消息内容：{}", data);
        MessageProperties properties = message.getMessageProperties();
        long deliveryTag = properties.getDeliveryTag()
        channel.basicAck(deliveryTag, false);
    }

}

二、死信队列实现

1、代码编写

1. 配置类

java 复制代码

@Configuration
public class RabbitMqConfig {
    
    public static final String DELAYED_EXCHANGE = "delayed.exchange";
    public static final String DELAYED_QUEUE = "delayed.queue";
    public static final String DELAYED_ROUTING_KEY = "delayed_routing_key";

    public static final String NORMAL_EXCHANGE = "normal.exchange";
    public static final String NORMAL_QUEUE = "normal.queue";
    public static final String NORMAL_ROUTING_KEY = "normal_routing_key";
 
    // 死信队列（延时队列）
    @Bean
    public Queue delayedQueue() {
        return QueueBuilder.durable(DELAYED_QUEUE).build();
    }

    // 死信交换机
    @Bean
    public DirectExchange delayedExchange() {
        return new DirectExchange(DELAYED_EXCHANGE);
    }

    // 绑定死信队列到死信交换机
    @Bean
    public Binding delayedBinding(Queue delayedQueue, 
                                  DirectExchange delayedExchange) {
        return BindingBuilder.bind(delayedQueue)
                .to(delayedExchange)
                .with(DELAYED_ROUTING_KEY);
    }

    // 普通队列
    @Bean
    public Queue normalQueue() {
        return QueueBuilder.durable(NORMAL_QUEUE)
                .deadLetterExchange(DELAYED_EXCHANGE)
                .deadLetterRoutingKey(DELAYED_ROUTING_KEY)
                .build();
    }

    // 普通交换机
    @Bean
    public DirectExchange normalExchange() {
        return new DirectExchange(NORMAL_EXCHANGE);
    }

    // 绑定普通队列到普通交换机
    @Bean
    public Binding normalBinding(Queue normalQueue, 
                                 DirectExchange normalExchange) {
        return BindingBuilder.bind(normalQueue)
                .to(normalExchange)
                .with(NORMAL_ROUTING_KEY);
    }
    
}

2. 生产者

java 复制代码

public void send(String exchange, String routing_key, 
                 Object data, Integer delayMillis) {
        String uuid = IdUtil.simpleUUID();
        // 消息入库略，uuid为主键
    
        MessageProperties properties = new MessageProperties();
        // 设置TTL，单位毫秒
        properties.setExpiration(String.valueOf(delayMillis));
        // 消息持久化（2 表示持久化）
        properties.setDeliveryMode(MessageDeliveryMode.PERSISTENT);

        Message msg = rabbitTemplate.getMessageConverter().toMessage(data, properties);
        rabbitTemplate.send(exchange, routingKey, msg, new CorrelationData(uuid));
}

3. 消费者

java 复制代码

@Component
@RabbitListener(queues = RabbitMqConfig.DELAYED_QUEUE)
public class DelayedListener {

    @RabbitHandler
    public void listener(String data, Channel channel, Message message) {
        log.warn("消息消费成功，消息内容：{}", data);
        MessageProperties properties = message.getMessageProperties();
        long deliveryTag = properties.getDeliveryTag()
        channel.basicAck(deliveryTag, false);
    }

}

三、踩坑记录

1、发送消息失败

原因：RabbitTemplate 配置了消息抵达确认，消息ID没有传值。

java 复制代码

RabbitTemplate rabbitTemplate = new RabbitTemplate();
// 消息抵达确认通知
rabbitTemplate.setConfirmCallback((data, ack, cause) -> {
    String msgId = data.getId();
    if (ack) {
        log.info("消息抵达队列成功:{}", data);
    } else {
        log.error("消息未能发送成功，消息ID:{}", data.getId(), cause);
    }
});

生产者实际发送消息未传消息ID：

错误格式

java 复制代码

rabbitTemplate.convertAndSend(exchange, routingKey, data);

正确格式

java 复制代码

String uuid = IdUtil.simpleUUID();
rabbitTemplate.convertAndSend(exchange, routingKey, data, new CorrelationData(uuid));

2、消息过期后未能转发到死信队列

原因：正常消息未绑定死信队列，消息过期自动删除，而不会转发到死信队列中。

错误格式

java 复制代码

@Bean
public Queue delayedNormalQueue() {
    return QueueBuilder.durable(NORMAL_QUEUE).build();
}

正确格式

java 复制代码

@Bean
public Queue delayedNormalQueue() {
    return QueueBuilder.durable(NORMAL_QUEUE)
        .deadLetterExchange(DELAYED_EXCHANGE) // 指定死信交换机
        .deadLetterRoutingKey(DELAYED_ROUTING_KEY) // 指定死信路由键
        .build();
}

3、消费者消费报错

原因：发送的消息由于自定义的 MessageProperties ，其中缺失了 contentType 参数，需要使用转化器进行转换，而不是直接发送消息。

错误格式

java 复制代码

MessageProperties properties = new MessageProperties();
properties.setExpiration(String.valueOf(delayMillis));

Message msg = new Message(message.getBytes(), properties);
rabbitTemplate.convertAndSend(exchange, routingKey, msg, new CorrelationData(uuid));

正确格式

java 复制代码

MessageProperties properties = new MessageProperties();
properties.setExpiration(String.valueOf(delayMillis));

Message msg = rabbitTemplate.getMessageConverter().toMessage(message, properties);
rabbitTemplate.send(exchange, routingKey, msg, new CorrelationData(uuid));