public interface GoodsService {

 /**
  * 通過lua腳本實現(xiàn)的秒殺
  * @param skuCode 商品編碼
  * @param buyNum 購買數(shù)量
  * @return 購買數(shù)量
  */
 Long flashSellByLuaScript(String skuCode,int buyNum);
 /**
  * 通過redis 事務(wù) 實現(xiàn)的秒殺
  * @param skuCode 商品編碼
  * @param buyNum 購買數(shù)量
  * @return 購買數(shù)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腳本
  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<String> re = new DefaultRedisScript<String>();
  //設(shè)置腳本
  re.setScriptText(luaScript);
  //定義返回值類型，注意，如果沒有這個定義，Spring不會返回結(jié)果
  re.setResultType(String.class);
  RedisSerializer<String> stringRedisSerializer = stringRedisTemplate.getStringSerializer();
  //執(zhí)行LUA腳本
  String result = (String) stringRedisTemplate.execute(re, stringRedisSerializer, stringRedisSerializer, null);
  return Long.valueOf(result);
 }

 @Override
 public Long flashSellByRedisWatch(String skuCode,int num){

  SessionCallback<Long> sessionCallback = new SessionCallback<Long>() {
   @Override
   public Long execute(RedisOperations operations) throws DataAccessException {
    int result = num;
    //redis 樂觀鎖
    //我們觀察商品編碼是否發(fā)生改變
    operations.watch(skuCode);
    ValueOperations<String, String> valueOperations = operations.opsForValue();
    String goodsNumStr = valueOperations.get(skuCode);
    Integer goodsNum = Integer.valueOf(goodsNumStr);
    //標(biāo)記一個事務(wù)塊的開始。
    //事務(wù)塊內(nèi)的多條命令會按照先后順序被放進一個隊列當(dāng)中，
    //最后由 EXEC 命令原子性(atomic)地執(zhí)行。
    operations.multi();
    if (goodsNum >= num) {
     valueOperations.increment(skuCode, 0 - num);
    } else {
     result = 0;
    }
    //多條命令執(zhí)行的結(jié)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 = "用事務(wù)秒殺測試接口", notes = "用事務(wù)秒殺測試接口")
@RequestMapping(value = "/miaoTransaction", method = RequestMethod.GET)
@ResponseBody
 public Long miaoTransaction() {

  Long res = goodsService.flashSellByRedisWatch("xiaomi", 1);
  return res;
 }


 @ApiOperation(value = " 秒殺Lua測試接口", notes = "秒殺Lua測試接口")
 @RequestMapping(value = "/miaoLua", method = RequestMethod.GET)
 @ResponseBody
 public Long miaoLua() {

  Long res = goodsService.flashSellByRedisWatch("xiaomi", 1);
  System.out.println(res.toString());
  return res;
 }