SpringClub09-RabbitMQ 拼多商城整合

拼多商城整合 rabbitmq

当用户下订单时,我们的业务系统直接与数据库通信,把订单保存到数据库中当系统流量突然激增,大量的订单压力,会拖慢业务系统和数据库系统
我们需要应对流量峰值,让流量曲线变得平缓,如下图

1.订单存储的解耦

为了进行流量削峰,我们引入 rabbitmq 消息队列,当购物系统产生订单后,可以把订单数据发送到消息队列;而订单消费者应用从消息队列接收订单消息,并把订单保存到数据库

这样,当流量激增时,大量订单会暂存在rabbitmq中,而订单消费者可以从容地从消息队列慢慢接收订单,向数据库保存.

2. 创建pdweb项目

从课前资料中导入项目即可

3. 定义生产者-发送订单

3.1 pom.xml 添加依赖

spring提供了更方便的消息队列访问接口,它对RabbitMQ的客户端API进行了封装,使用起来更加方便

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

3.2 修改 application.yml 文件

添加RabbitMQ的连接信息

spring:
  rabbitmq:
    host: 192.168.64.140
    port: 5672
    virtualHost: /pd
    username: admin
    password: admin 

3.3 修改主程序 RunPdAPP

在主程序中添加下面的方法创建Queue实例
当创建RabbitMQ连接和信道后,Spring的RabbitMQ工具会自动在服务器中创建队列,代码在RabbitAdmin.declareQueues()方法中

 @Bean
    public Queue getQueue() {
        Queue q = new Queue("orderQueue", true);
        return q;
    }

3.4 修改 OrderServiceImpl

 //RabbitAutoConfiguration中创建了AmpqTemplate实例
    @Autowired
    AmqpTemplate amqpTemplate;
    //saveOrder原来的数据库访问代码全部注释,添加rabbitmq消息发送代码
    public String saveOrder(PdOrder pdOrder) throws Exception {
        String orderId = generateId();
        pdOrder.setOrderId(orderId);

        amqpTemplate.convertAndSend("orderQueue", pdOrder);
        return orderId;

        
        //        String orderId = generateId();
        //        pdOrder.setOrderId(orderId);
        //
        // 
        //        PdShipping pdShipping = pdShippingMapper.selectByPrimaryKey(pdOrder.getAddId());
        //        pdOrder.setShippingName(pdShipping.getReceiverName());
        //        pdOrder.setShippingCode(pdShipping.getReceiverAddress());
        //        pdOrder.setStatus(1);// 
        //        pdOrder.setPaymentType(1);
        //        pdOrder.setPostFee(10D);
        //        pdOrder.setCreateTime(new Date());
        //
        //        double payment = 0;
        //        List<ItemVO> itemVOs = selectCartItemByUseridAndItemIds(pdOrder.getUserId(), pdOrder.getItemIdList());
        //        for (ItemVO itemVO : itemVOs) {
        //            PdOrderItem pdOrderItem = new PdOrderItem();
        //            String id = generateId();
        //            //String id="2";
        //            pdOrderItem.setId(id);
        //            pdOrderItem.setOrderId(orderId);
        //            pdOrderItem.setItemId("" + itemVO.getPdItem().getId());
        //            pdOrderItem.setTitle(itemVO.getPdItem().getTitle());
        //            pdOrderItem.setPrice(itemVO.getPdItem().getPrice());
        //            pdOrderItem.setNum(itemVO.getPdCartItem().getNum());
        //
        //            payment = payment + itemVO.getPdCartItem().getNum() * itemVO.getPdItem().getPrice();
        //            pdOrderItemMapper.insert(pdOrderItem);
        //        }
        //        pdOrder.setPayment(payment);
        //        pdOrderMapper.insert(pdOrder);
        //        return orderId;
    }

4. 消费者-接收订单,并保存到数据库

4.1 pd-web项目复制为pd-order-consumer

4.2 修改 application.yml 文件

把端口修改成 81

server:
  port: 81

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/pd_store?useUnicode=true&characterEncoding=utf8
    username: root
    password: root

  rabbitmq:
    host: 192.168.64.140
    port: 5672
    virtualHost: /pd
    username: admin
    password: admin

mybatis:
  #typeAliasesPackage: cn.tedu.ssm.pojo
  mapperLocations: classpath:com.pd.mapper/*.xml

logging:
  level: 
    cn.tedu.ssm.mapper: debug

4.3 新建 OrderConsumer

package com.pd;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.pd.pojo.PdOrder;
import com.pd.service.OrderService;
@Component
public class OrderConsumer {
    //收到订单数据后,会调用订单的业务代码,把订单保存到数据库
    @Autowired
    private OrderService orderService;

    //添加该注解后,会从指定的orderQueue接收消息,
    //并把数据转为 PdOrder 实例传递到此方法
    @RabbitListener(queues="orderQueue")
    public void save(PdOrder pdOrder)
    {
        System.out.println("消费者");
        System.out.println(pdOrder.toString());
        try {
            orderService.saveOrder(pdOrder);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

4.4 修改 OrderServiceImpl 的 saveOrder() 方法

 public String saveOrder(PdOrder pdOrder) throws Exception {
        //        String orderId = generateId();
        //        pdOrder.setOrderId(orderId);
        //
        //        amqpTemplate.convertAndSend("orderQueue", pdOrder);
        //        return orderId;
        //
        // 
        // 
        //        String orderId = generateId();
        //        pdOrder.setOrderId(orderId);
        
        //从RabbitMQ接收的订单数据,
        //已经在上游订单业务中生成过id,这里不再重新生成id
        //直接获取该订单的id
        String orderId = pdOrder.getOrderId();

        
        PdShipping pdShipping = pdShippingMapper.selectByPrimaryKey(pdOrder.getAddId());
        pdOrder.setShippingName(pdShipping.getReceiverName());
        pdOrder.setShippingCode(pdShipping.getReceiverAddress());
        pdOrder.setStatus(1);// 
        pdOrder.setPaymentType(1);
        pdOrder.setPostFee(10D);
        pdOrder.setCreateTime(new Date());

        double payment = 0;
        List<ItemVO> itemVOs = selectCartItemByUseridAndItemIds(pdOrder.getUserId(), pdOrder.getItemIdList());
        for (ItemVO itemVO : itemVOs) {
            PdOrderItem pdOrderItem = new PdOrderItem();
            String id = generateId();
            //String id="2";
            pdOrderItem.setId(id);
            pdOrderItem.setOrderId(orderId);
            pdOrderItem.setItemId("" + itemVO.getPdItem().getId());
            pdOrderItem.setTitle(itemVO.getPdItem().getTitle());
            pdOrderItem.setPrice(itemVO.getPdItem().getPrice());
            pdOrderItem.setNum(itemVO.getPdCartItem().getNum());

            payment = payment + itemVO.getPdCartItem().getNum() * itemVO.getPdItem().getPrice();
            pdOrderItemMapper.insert(pdOrderItem);
        }
        pdOrder.setPayment(payment);
        pdOrderMapper.insert(pdOrder);
        return orderId;
    } 

5. 手动确认

5.1 修改 application.yml 文件

spring:
  rabbitmq:
    listener:
      simple:
        acknowledge-mode: manual` 

5.2 OrderConsumer

package com.pd;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.pd.pojo.PdOrder;
import com.pd.service.OrderService;
import com.rabbitmq.client.Channel;
@Component
public class OrderConsumer {
    //收到订单数据后,会调用订单的业务代码,把订单保存到数据库
    @Autowired
    private OrderService orderService;

    //添加该注解后,会从指定的orderQueue接收消息,
    //并把数据转为 PdOrder 实例传递到此方法
    @RabbitListener(queues="orderQueue")
    public void save(PdOrder pdOrder, Channel channel, Message message)
    {
        System.out.println("消费者");
        System.out.println(pdOrder.toString());
        try {
            orderService.saveOrder(pdOrder);
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
        } catch (Exception e) {
            e.printStackTrace();
        } 
    }
}