SpringMVC集成rabbitmq：优化秒杀下单环节

2019-02-17 01:49:45来源：博客园阅读 ()

前言

上一篇在springboot中基于自动配置集成了rabbitmq。那么回到最初的话题中就是想在秒杀下单环节增加排队机制，从而达到限流的目的。

优化秒杀下单流程

之前是在控制器里拿到客户端请求后直接入库、减库存。如果碰到羊毛党其实这套机制是不行的。并发量高的时候，库存数量也会不准确。那么引入rabbitmq则在下单时让用户信息产生一条消息入队。然后消费者处理下单（是否重复下单、下单失败、库存不够）。客户端接受到请求已入队列（response引入state处理交互）后发起ajax轮询请求，处理成功则跳转下单成功页或者结束本次交互。

1、下单（秒杀接口）

@RequestMapping(value="/{seckillId}/{md5}/execute",method = RequestMethod.POST,produces = {"application/json;charset=UTF-8"})
    @ResponseBody
    public SeckillResult<SeckillExecution> execute(@PathVariable("seckillId")Long seckillId,
                                                   @PathVariable("md5")String md5,
                                                   @CookieValue(value="phone",required=false)Long phone){

        if(phone==null){
            return new SeckillResult<SeckillExecution>(false,"手机号未注册");
        }

        SeckillResult<SeckillExecution> result=null;

        try{

            SeckillExecution execution=seckillService.executeSeckill(seckillId,phone,md5);
            result=new SeckillResult<SeckillExecution>(true,execution);

        }catch(RepeatKillException e){

            SeckillExecution execution=new SeckillExecution(seckillId,-1,"重复秒杀");
            result=new SeckillResult<SeckillExecution>(true,execution);


        }catch(SeckillCloseException e){

            SeckillExecution execution=new SeckillExecution(seckillId,0,"秒杀结束");
            result=new SeckillResult<SeckillExecution>(true,execution);

        }catch (Exception e){

            SeckillExecution execution=new SeckillExecution(seckillId,-2,"系统异常");
            result=new SeckillResult<SeckillExecution>(true,execution);

        }

        return result;

    }

2、下单业务方法（Service）这里就要引入排队

 @Override
    public SeckillExecution executeSeckill(long seckillId, long phone, String md5)
            throws SeckillException,RepeatKillException,SeckillCloseException {

        if (md5 == null || !md5.equals(getMd5(seckillId))) {
            throw new SeckillException("非法请求");
        }

        Date now = new Date();

        try {
            int insertCount = successKillDao.insertSuccessKilled(seckillId, phone);
            if (insertCount <= 0) {
                throw new RepeatKillException("重复秒杀");

            } else {

                //请求入队
                MiaoshaUser miaoshaUser=new MiaoshaUser();
                miaoshaUser.setPhone(phone);

                MiaoshaMessage miaoshaMessage=new MiaoshaMessage();
                miaoshaMessage.setSeckillId(seckillId);
                miaoshaMessage.setMiaoshaUser(miaoshaUser);

                String miaosha=JSON.toJSONString(miaoshaMessage);
                amqpTemplate.convertAndSend(miaosha);

                return new SeckillExecution(seckillId,0,"请求入队");

                /***
                 * 直接入库操作
                int updateCount = seckillDao.reduceNumber(seckillId, now);
                if (updateCount <= 0) {
                    throw new SeckillCloseException("秒杀已关闭");
                } else {
                    //秒杀成功，可以把秒杀详情和商品详情实体返回
                    SuccessKilled successKilled = successKillDao.queryByIdWithSeckill(seckillId, phone);
                    return new SeckillExecution(seckillId, 1, "秒杀成功", successKilled);
                }
                 ***/
            }

        } catch (SeckillCloseException e) {
            throw e;
        } catch (RepeatKillException e1) {
            throw e1;
        } catch (SeckillException e2) {
            logger.error(e2.getMessage(), e2);
            throw new SeckillException("Unkonwn error:" + e2.getMessage());
        }

    }

3、下单结果接口

@RequestMapping(value="/{seckillId}/{md5}/result",method = RequestMethod.GET,produces = {"application/json;charset=UTF-8"})
    @ResponseBody
    public SeckillResult<SeckillExecution> result(@PathVariable("seckillId")Long seckillId,
                                                  @PathVariable("md5")String md5,
                                                  @CookieValue(value="phone",required=false)Long phone){

        SuccessKilled successKilled = seckillService.queryByIdWithSeckill(seckillId, phone);
        SeckillExecution execution=null;
        if(successKilled.getSeckillId()>0){
            execution=new SeckillExecution(seckillId, 1, "下单成功", successKilled);
        }else{
            execution=new SeckillExecution(seckillId, -2, "下单失败", successKilled);
        }

        return new SeckillResult<SeckillExecution>(true,execution);
    }

4、消费者（下单处理）

/**
 * 秒杀请求消费
 **/
public class AmqpConsumer implements MessageListener {

    @Autowired
    SeckillDao seckillDao;

    @Autowired
    SuccessKillDao successKillDao;


    @Override
    public void onMessage(Message message) {
        Date now = new Date();

        MiaoshaMessage miaosha = JSON.parseObject(message.getBody(), MiaoshaMessage.class);

        Long seckillId = miaosha.getSeckillId();
        int updateCount = seckillDao.reduceNumber(seckillId, now);
        if (updateCount <= 0) {
            System.out.println("秒杀下单失败");
        } else {
            System.out.println("秒杀下单成功");

        }


    }
}

5、springmvc集成消息队列配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:rabbit="http://www.springframework.org/schema/rabbit"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/rabbit http://www.springframework.org/schema/rabbit/spring-rabbit.xsd">

    <!--spring集成rabbitmq-->
    <rabbit:connection-factory id="connectionFactory"
                               host="192.168.80.128"
                               port="5672"
                               username="admin"
                               password="admin"
                               channel-cache-size="5"
                               virtual-host="/" />

    <rabbit:admin connection-factory="connectionFactory"/>
    <!--声明队列-->
    <rabbit:queue durable="true" auto-delete="false" exclusive="false" name="miaosha.queue"/>

    <!--交换器和队列绑定-->
    <rabbit:direct-exchange name="miaosha.exchange">
        <rabbit:bindings>
            <rabbit:binding queue="miaosha.queue" key="miaosha.tag.key"/>
        </rabbit:bindings>
    </rabbit:direct-exchange>

    <!--spring rabbitmqTemplate声明-->
    <rabbit:template id="rabbitTemplate"
                     exchange="miaosha.exchange"
                     routing-key="miaosha.tag.key"
                     connection-factory="connectionFactory" />

    <!--消息监听-->
    <bean id="miaoshaConsumer" class="com.seckill.mq.AmqpConsumer"/>
    <rabbit:listener-container connection-factory="connectionFactory" acknowledge="auto">
        <rabbit:listener ref="miaoshaConsumer" queues="miaosha.queue"/>
    </rabbit:listener-container>
</beans>

6、客户端秒杀下单、等待下单结果

 /**秒杀结果**/
    miaosha:function(seckillId,md5,node){
        $.get('/seckill/'+seckillId+'/'+md5+'/result',{},function(result){
            if(result && result["success"]){
                var oData=result["data"];
                if(oData["state"]===1){
                    node.html("<span class='label label-success'>下单成功</span>");

                    clearInterval(miaoshaTimer);
                }else{
                    console.log("还在排队种...");
                }
            }
        })
    },
    /**执行秒杀**/
    seckill:function(seckillId,node){

        //获取秒杀地址、控制node节点显示，执行秒杀
        node.hide().html("<button id='killBtn' class='btn btn-primary btn-lg'>开始秒杀</button>")

        $.get('/seckill/'+seckillId+'/exposer',{},function(result){

            if(result && result["success"]){
                //在回调函数中执行秒杀操作
                var exposer=result["data"];
                if(exposer["exposed"]){
                    //秒杀已开始
                    var md5=exposer["md5"];
                    var killUrl='/seckill/'+seckillId+'/'+md5+'/execute';
                    console.log(killUrl);

                    $("#killBtn").one('click',function(){
                        //1、禁用秒杀按钮
                        $(this).addClass('disabled');
                        //2、执行秒杀操作
                        $.post(killUrl,{},function(result){
                            if(result && result["success"]){
                                var killResult=result["data"];
                                var state=killResult["state"];
                                var stateInfo=killResult["stateInfo"];

                                node.html("<span class='label label-success'>"+stateInfo+"</span>");
                                if(state===0){
                                    //已入队，客户端开始轮询
                                    miaoshaTimer=setInterval(function(){
                                       seckill.miaosha(seckillId,md5,node);
                                    },3000);
                                }
                            }
                        })

                    });

                    node.show();
                }else{
                    //秒杀未开始， 防止浏览器和服务器出现时间差，再次执行倒数计时
                    var now = exposer['now'];
                    var start = exposer['start'];
                    var end = exposer['end'];
                    seckill.countdown(seckillId, now, start, end);
                }

            }else{
                console.log('result:'+result); //没有拿到秒杀地址
            }

        })

    }

　好了，贴了这么多代码，没有示意图怎么能行？