保姆级Redis秒杀解决方案设计(lua脚本解读)

	public  boolean doSecKill(String uid,String prodid)
	{

		Jedis jedis = new Jedis("120.79.14.203",6379);
		jedis.auth("123456");
		//1:uid和proid的非空判断
		if (uid==null||prodid==null){
			return false;
		}
		System.out.println(uid);
		System.out.println(prodid);
		//3.1库存key
		String kckey = "sk"+prodid+"qt";

		//3.2秒杀成功用户key
		String userkey = "sk"+prodid+"user";
		//4 获取库存本身等于空,秒杀还没有开始
		jedis.watch(kckey);
		System.out.println(kckey);
		String s = jedis.get(kckey);
		if (s==null){
			System.out.println("秒杀还没有开始,请等待");

			return false;
		}
		//5.用户是否重复秒杀操作
		Boolean member = jedis.sismember(userkey, uid);
		if (member){
			System.out.println("你已经秒杀过了不要再次重复的秒杀");

			return false;
		}
		//6.秒杀的过程
		if (Integer.parseInt(s)<=0){
			System.out.println("秒杀已经结束了");

			return false;
		}
		//7秒杀过程
		Transaction multi = jedis.multi();
		//7.1库存-1
		multi.decr(kckey);

		//7.2把秒杀成功的用户添加到redis
		multi.sadd(userkey,uid);
		List exec = multi.exec();
		System.out.println(exec);
		if (exec==null || exec.size()==0){
			System.out.println("秒杀失败了");
			return false;
		}
		System.out.println("秒杀成功");
		return true;
	}

package com.hyc.serkill.config;

import org.slf4j.LoggerFactory;
import redis.clients.jedis.HostAndPort;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;

import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

public class SecKill_redisByScript {

	private static final  org.slf4j.Logger logger =LoggerFactory.getLogger(SecKill_redisByScript.class) ;

	public static void main(String[] args) {
		JedisPool jedispool =  JedisPoolUtil.getJedisPoolInstance();

		Jedis jedis=jedispool.getResource();
		System.out.println(jedis.ping());

		Set<HostAndPort> set=new HashSet<HostAndPort>();

	//	doSecKill("201","sk:0101");
	}

	static String secKillScript =
            "local userid=KEYS[1];\r\n" +
			"local prodid=KEYS[2];\r\n" +
			"local qtkey='sk'..prodid..\"qt\";\r\n" +
			"local usersKey='sk'..prodid..\":usr\"\r\n" +
			"local userExists=redis.call(\"sismember\",usersKey,userid);\r\n" +
			"if tonumber(userExists)==1 then \r\n" +
			"   return 2;\r\n" +
			"end\r\n" +
			"local num= redis.call(\"get\" ,qtkey);\r\n" +
			"if tonumber(num)<=0 then \r\n" +
			"   return 0;\r\n" +
			"else \r\n" +
			"   redis.call(\"decr\",qtkey);\r\n" +
			"   redis.call(\"sadd\",usersKey,userid);\r\n" +
			"end\r\n" +
			"return 1" ;

	static String secKillScript2 =
			"local userExists=redis.call(\"sismember\",\"{sk}:0101:usr\",userid);\r\n" +
			" return 1";
}

			//获得参数1
            "local userid=KEYS[1];\r\n" +  
            //获得参数2
			"local prodid=KEYS[2];\r\n" +
			//生成秒杀库存key
			"local qtkey='sk'..prodid..\"qt\";\r\n" +
			//生成秒杀库存key
			"local usersKey='sk'..prodid..\":usr\"\r\n" +
			//判断redis查找set集合中userid的数字
			"local userExists=redis.call(\"sismember\",usersKey,userid);\r\n" +
			//如果返回是1那么表示已经秒杀过了,retrun2:代表抢购过了,方便后续调用判断
			"if tonumber(userExists)==1 then \r\n" +
			"   return 2;\r\n" +
			"end\r\n" +
			//获取库存
			"local num= redis.call(\"get\" ,qtkey);\r\n" +
			//判断如果小于等于0那么返回0 表示已经没有了
			"if tonumber(num)<=0 then \r\n" +
			"   return 0;\r\n" +
			//要是不等于0执行库存减少操作,将用户的id存入道用户key中,返回1 代表秒杀成功
			"else \r\n" +
			"   redis.call(\"decr\",qtkey);\r\n" +
			"   redis.call(\"sadd\",usersKey,userid);\r\n" +
			"end\r\n" +
			"return 1" ;

	public static boolean doSecKill(String uid,String prodid) throws IOException {

		JedisPool jedispool =  JedisPoolUtil.getJedisPoolInstance();
		Jedis jedis=jedispool.getResource();

		 //String sha1=  .secKillScript;
		String sha1=  jedis.scriptLoad(secKillScript);
		Object result= jedis.evalsha(sha1, 2, uid,prodid);

		  String reString=String.valueOf(result);
		if ("0".equals( reString )  ) {
			System.err.println("已抢空！！");
		}else if("1".equals( reString )  )  {
			System.out.println("抢购成功！！！！");
		}else if("2".equals( reString )  )  {
			System.err.println("该用户已抢过！！");
		}else{
			System.err.println("抢购异常！！");
		}
		jedis.close();
		return true;
	}

package com.hyc.serkill.config;

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

public class JedisPoolUtil {
	private static volatile JedisPool jedisPool = null;

	private JedisPoolUtil() {
	}

	public static JedisPool getJedisPoolInstance() {
		if (null == jedisPool) {
			synchronized (JedisPoolUtil.class) {
				if (null == jedisPool) {
					JedisPoolConfig poolConfig = new JedisPoolConfig();
					//最大两百实例
					poolConfig.setMaxTotal(200);
					//最多有30左右的空闲实例
					poolConfig.setMaxIdle(32);
					//连接超时毫秒数
					poolConfig.setMaxWaitMillis(100*1000);

					poolConfig.setBlockWhenExhausted(true);
					// ping  PONG
					poolConfig.setTestOnBorrow(true);

					jedisPool = new JedisPool(poolConfig, "120.79.14.203", 6379, 60000 ,"123456");
				}
			}
		}
		return jedisPool;
	}

	//资源回收
	public static void release(JedisPool jedisPool, Jedis jedis) {
		if (null != jedis) {
			jedisPool.returnResource(jedis);
		}
	}

}