springboot集成redis实现简单秒杀系统

 public interface GoodsService { /** * 通过lua脚本实现的秒杀 * @param skuCode 商品编码 * @param buyNum 购买数量 * @return 购买数量 */ Long flashSellByLuaScript(String skuCode,int buyNum); /** * 通过redis 事务 实现的秒杀 * @param skuCode 商品编码 * @param buyNum 购买数量 * @return 购买数量 */ Long flashSellByRedisWatch(String skuCode,int buyNum); }

 import org.springframework.dao.DataAccessException; import org.springframework.data.redis.core.RedisOperations; import org.springframework.data.redis.core.SessionCallback; import org.springframework.data.redis.core.StringRedisTemplate; import org.springframework.data.redis.core.ValueOperations; import org.springframework.data.redis.core.script.DefaultRedisScript; import org.springframework.data.redis.serializer.RedisSerializer; import org.springframework.stereotype.Service; import javax.annotation.Resource; import java.util.Collections; import java.util.List; @Service public class GoodsServiceImpl implements GoodsService { @Resource private StringRedisTemplate stringRedisTemplate; @Override public Long flashSellByLuaScript(String skuCode,int num) { //下面是lua脚本 String luaScript ="local buyNum = ARGV[1]\n" + "local goodsKey = KEYS[1] \n" + "local goodsNum = redis.call('get',goodsKey) \n" + "if goodsNum >= buyNum \n" + "then redis.call('decrby',goodsKey,buyNum) \n" + "return buyNum \n" + "else \n" + "return '0'\n" + "end\n" + "\n" ; DefaultRedisScript re = new DefaultRedisScript(); //设置脚本 re.setScriptText(luaScript); //定义返回值类型，注意，如果没有这个定义，Spring不会返回结果 re.setResultType(String.class); RedisSerializer stringRedisSerializer = stringRedisTemplate.getStringSerializer(); //执行LUA脚本 String result = (String) stringRedisTemplate.execute(re, stringRedisSerializer, stringRedisSerializer, null); return Long.valueOf(result); } @Override public Long flashSellByRedisWatch(String skuCode,int num){ SessionCallback sessionCallback = new SessionCallback() { @Override public Long execute(RedisOperations operations) throws DataAccessException { int result = num; //redis 乐观锁 //我们观察商品编码是否发生改变 operations.watch(skuCode); ValueOperations valueOperations = operations.opsForValue(); String goodsNumStr = valueOperations.get(skuCode); Integer goodsNum = Integer.valueOf(goodsNumStr); //标记一个事务块的开始。 //事务块内的多条命令会按照先后顺序被放进一个队列当中， //最后由 EXEC 命令原子性(atomic)地执行。 operations.multi(); if (goodsNum >= num) { valueOperations.increment(skuCode, 0 - num); } else { result = 0; } //多条命令执行的结果集合 List exec = operations.exec(); if(exec.size()>0){ System.out.println(exec); } return (long) result; } }; return stringRedisTemplate.execute(sessionCallback); } //省略 其他的方法 }

 @ApiOperation(value = "用事务秒杀测试接口", notes = "用事务秒杀测试接口") @RequestMapping(value = "/miaoTransaction", method = RequestMethod.GET) @ResponseBody public Long miaoTransaction() { Long res = goodsService.flashSellByRedisWatch("xiaomi", 1); return res; } @ApiOperation(value = " 秒杀Lua测试接口", notes = "秒杀Lua测试接口") @RequestMapping(value = "/miaoLua", method = RequestMethod.GET) @ResponseBody public Long miaoLua() { Long res = goodsService.flashSellByRedisWatch("xiaomi", 1); System.out.println(res.toString()); return res; }