一、流程图

二、导包

<!--消息队列 AMQP依赖，包含RabbitMQ-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

三、配置文件

#消息队列
spring:
  rabbitmq:
    host: 192.168.88.130
    port: 5672
    virtual-host: my_vhost #使用的虚拟主机
    username: root
    password: root
    listener:
      simple:
        acknowledge-mode: manual #开启手动应答

四、配置类

import org.springframework.amqp.core.*;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.HashMap;
import java.util.Map;

@Configuration
public class RabbitMQConfig {
    /**
     * 订单交换机
     */
    public static final String ORDER_EXCHANGE = "order_exchange";
    /**
     * 订单队列
     */
    public static final String ORDER_QUEUE = "order_queue";
    /**
     * 订单路由键
     */
    public static final String ORDER_ROUTING = "order_routing";
    /**
     * 死信交换机
     */
    public static final String ORDER_DEAD_EXCHANGE = "order_dead_exchange";
    /**
     * 死信队列
     */
    public static final String ORDER_DEAD_QUEUE = "order_dead_queue";
    /**
     * 死信路由键
     */
    public static final String ORDER_DEAD_ROUTING = "order_dead_routing";

    /**
     * 订单交换机
     */
    @Bean("orderExchange")
    public Exchange getOrderExchange() {
        return new DirectExchange(ORDER_EXCHANGE);
    }

    /**
     * 订单队列
     */
    @Bean("orderQueue")
    public Queue getOrderQueue() {
        Map<String, Object> map = new HashMap<>(3);
        map.put("x-dead-letter-exchange", ORDER_DEAD_EXCHANGE);//死信交换机
        map.put("x-dead-letter-routing-key", ORDER_DEAD_ROUTING);//死信路由键
        map.put("x-message-ttl", 1000 * 60 * 15);//队列过期时间
        return QueueBuilder
                .durable(ORDER_QUEUE)
                .withArguments(map)
                .build();
    }

    /**
     * 将订单交换机与订单队列绑定
     */
    @Bean
    Binding orderExchangeBindingOrder(@Qualifier("orderExchange") Exchange exchange,
                                      @Qualifier("orderQueue") Queue queue) {
        return BindingBuilder.bind(queue).to(exchange).with(ORDER_ROUTING).noargs();
    }

    /**
     * 死信交换机
     */
    @Bean("orderDeadExchange")
    public Exchange getOrderDeadExchange() {
        return new DirectExchange(ORDER_DEAD_EXCHANGE);
    }

    /**
     * 死信队列
     */
    @Bean("orderDeadQueue")
    public Queue getOrderDeadQueue() {
        return new Queue(
                ORDER_DEAD_QUEUE,//队列名
                true,//是否持久化
                false,//是否具有排他性，只在首次声明时可见，不允许其他用户访问，连接断开时自动删除
                false,//是否自动删除，经历过至少一次连接后，所有消费者都断开了连接，此队列会自动删除
                null
        );
    }

    /**
     * 将死信交换机与死信队列绑定
     */
    @Bean
    Binding deadExchangeBindingDeadQueue(@Qualifier("orderDeadExchange") Exchange exchange,
                                         @Qualifier("orderDeadQueue") Queue queue) {
        return BindingBuilder.bind(queue).to(exchange).with(ORDER_DEAD_ROUTING).noargs();
    }
}

五、发送消息的类

import com.sky.configuration.RabbitMQConfig;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * 消息队列发送消息
 */
@Component
public class SendRabbitMQ {
    @Autowired
    private RabbitTemplate rabbitTemplate;

    /**
     * @param orderId 15分钟后要检查的订单编号
     */
    public void sendDelayOrder(Long orderId) {
        rabbitTemplate.convertAndSend(
                RabbitMQConfig.ORDER_EXCHANGE,//订单交换机
                RabbitMQConfig.ORDER_ROUTING,//订单路由键
                orderId//要取消的订单编号
        );
    }
}

六、接收消息的类

import com.rabbitmq.client.Channel;
import com.sky.configuration.RabbitMQConfig;
import com.sky.mapper.OrderMapper;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;

/**
 * 消息队列接收消息
 */
@Component
public class ReceiveRabbitMQ {
    @Autowired
    private OrderMapper orderMapper;

    /**
     * @param orderId 要取消的订单的编号
     * @param msg     包含了要回复的队列
     * @param channel 有回复功能的参数
     */
    @RabbitListener(queues = RabbitMQConfig.ORDER_DEAD_QUEUE)
    public void ReceiveDeadOrder(Long orderId, Channel channel, Message msg) throws IOException {
        orderMapper.delCancelOrder(orderId);//查询数据库，订单是否付款，未付款：改为已取消
        channel.basicAck(msg.getMessageProperties().getDeliveryTag(),//应答的消息
                false//是否批量应答
        );
    }
}

七、在业务代码中注入发送类，并调用发送类的发送方法

@Service
public class OrderServiceImpl implements OrderService {
    @Autowired
    private SendRabbitMQ sendRabbitMQ;
    /**
     * 用户下单
     */
    public void submitOrder(OrdersSubmitDTO ordersSubmitDTO) {
        sendRabbitMQ.sendDelayOrder(order.getId());//发送延迟消息到消息队列
    }
}