java redis 实现抢购秒杀

Posted 2021-01-14 2019美丽的梦

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了java redis 实现抢购秒杀相关的知识，希望对你有一定的参考价值。

2018.10.24 今天研究了下抢购秒杀的功能实现

网上查了一大堆用redis的最多。

主要是通过redis的 watch multi 事务来控制秒杀数量不超卖。

这里说下自己的感受：

不超卖的话那就要一个个的来减库存这样的话效率上会有点问题这里上下代码基本上是再网上抄的。

我用的是 springboot jedis

我就直接上代码了

Controller层

package com.bicon.basedemo.controller;

import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import javax.annotation.Resource;

import org.omg.CORBA.PRIVATE_MEMBER;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;


@RestController
@RequestMapping("/test")
public class test {
    
//    @Resource
//    RedisOperation redisOps;
    
    @Resource
    private JedisPool jedisPool;

    @RequestMapping("/redis")
    public void redisTest() {
        Jedis jedis = jedisPool.getResource();
        final String watchkeys = "watchkeys";
        ExecutorService executor = Executors.newFixedThreadPool(20);  //20个线程池并发数

        jedis.set(watchkeys, "10");//设置起始的抢购数
       // jedis.del("setsucc", "setfail");
        jedis.close();
         
        for (int i = 0; i < 101; i++) {//设置101个人来发起抢购 模拟101个人抢购
            executor.execute(new MyRunnable(jedisPool));
        }
        executor.shutdown();
    }
    
     public static String getRandomString(int length) { //length是随机字符串长度
         String base = "abcdefghijklmnopqrstuvwxyz0123456789";  
         Random random = new Random();  
         StringBuffer sb = new StringBuffer();  
         for (int i = 0; i < length; i++) {  
             int number = random.nextInt(base.length());  
             sb.append(base.charAt(number));  
         }  
         return sb.toString();  
      } 
}


MyRunnable 代码

package com.bicon.basedemo.controller;

import java.util.List;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.Transaction;

public class MyRunnable implements Runnable{
    
    
    private JedisPool jedisPool;
    String userinfo;
    String watchkeys = "watchkeys";
    public MyRunnable(JedisPool jedisPoo){
        jedisPool = jedisPoo;
    };
    
    public void run() {
        Jedis jedis = jedisPool.getResource();
        try {
            jedis.watch(watchkeys);// watchkeys
 
            String val = jedis.get(watchkeys);
            int valint = Integer.valueOf(val);
            
            if (valint <= 100 && valint>=1) {
            
                 Transaction tx = jedis.multi();// 开启事务
               // tx.incr("watchkeys");
                tx.incrBy("watchkeys", -1);
 
                List<Object> list = tx.exec();// 提交事务，如果此时watchkeys被改动了，则返回null
                 
                if (list == null ||list.size()==0) {
                    System.out.println("重新抢购");
                    this.run();
                    return;
                } else {
                    for(Object succ : list){
                         String succuserifo ="succ"+succ.toString() +userinfo ;
                         String succinfo="用户：" + succuserifo + "抢购成功，当前抢购成功人数:"
                                 + (1-(valint-10));
                         System.out.println(succinfo);
                         /* 抢购成功业务逻辑 */
                         jedis.setnx(succuserifo, succinfo);
                    }
                }
            } else {
                    String failuserifo ="kcfail" +  userinfo;
                    String failinfo1="用户：" + failuserifo + "商品被抢购完毕，抢购失败";
                    System.out.println(failinfo1);
                    jedis.setnx(failuserifo, failinfo1);
                    return;
            }
 
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            jedis.close();
        }
    }

}