Redis分布式锁使用+Redis处理数据并发+springboot整合Redis

package com.txc.redisconcurrency.controller; import com.txc.redisconcurrency.exception.MyException; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.ValueOperations; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import javax.annotation.Resource; import javax.servlet.http.HttpSession; import java.util.UUID; import java.util.concurrent.TimeUnit; @Controller public class StockController { @Resource private RedisTemplate<String,String> redisTemplate; //查询库存后，修改库存信息 @RequestMapping("/changeStock") @ResponseBody public void changeStock(HttpSession session){ //假设每次购买的产品数量为2 int buyCount=2; //创建操作Redis字符串参数对象 ValueOperations<String,String> opsString=redisTemplate.opsForValue(); // String lockKey="stock";//需要加锁的key,这个key是自定义的key String goodsKey="goods:mobile.huawei001";//逆向修改的商品的key String sessionId=session.getId();//确保加锁和解锁的是同一个人。 //在查询lockKey之前，先给lockKey加锁，然后再查询数据，然后再修改数据，最后解锁 boolean lockResult=false; try{ lockResult=opsString.setIfAbsent(lockKey,sessionId,30, TimeUnit.SECONDS); }catch (Exception e){ System.out.println("============加锁失败============"); e.printStackTrace(); } System.out.println("=======lockResult====="+lockResult); if(lockResult){ try{ //查询数据 int stockCount=Integer.valueOf(opsString.get(goodsKey)); if (stockCount>=2){//判断库存是否足够 //库存数量减去购买的数量 stockCount=stockCount-buyCount; System.out.println(lockKey+"===1==="+stockCount); //将新的库存信息重写写入到redis中 opsString.set(goodsKey,stockCount+""); }else{ System.out.println("=========库存不足========"); } }catch(Exception e){ e.printStackTrace(); System.out.println("=========程序异常，请重新操作========="); }finally { //释放锁 System.out.println("========锁释放成功======="); redisTemplate.delete(lockKey); } }else{ //key已加锁，稍后重试 throw new MyException(); } } /** * 查询库存后，修改库存信息 * 解决极端情况下，setIfAbsent的并发问题 * @param session */ @RequestMapping("/changeStock_upgrad") @ResponseBody public void changeStock_upgrad(HttpSession session){ //假设每次购买的产品数量为2 int buyCount=2; //创建操作Redis字符串参数对象 ValueOperations<String,String> opsString=redisTemplate.opsForValue(); String lockKey="stock";//需要加锁的key,这个key是自定义的key String goodsKey="goods:mobile.huawei001";//逆向修改的商品的key boolean lockResult=false; //生成一个随机的唯一的id String lockValue= UUID.randomUUID().toString(); try{ //在查询lockKey之前，先给lockKey加锁，然后再查询数据，然后再修改数据，最后解锁 lockResult=opsString.setIfAbsent(lockKey,lockValue,30, TimeUnit.SECONDS); }catch (Exception e){ System.out.println("============加锁失败============"); e.printStackTrace(); } System.out.println("=======lockResult====="+lockResult); if(lockResult){ try{ //判断二次lockValue的值是否相等，解决极端情况下并发问题 String lockValue1=opsString.get(lockKey); if(lockValue1.equals(lockValue)){ //查询数据 int stockCount=Integer.valueOf(opsString.get(goodsKey)); if (stockCount>=2){//判断库存是否足够 //库存数量减去购买的数量 stockCount=stockCount-buyCount; System.out.println(lockKey+"===1==="+stockCount); //将新的库存信息重写写入到redis中 opsString.set(goodsKey,stockCount+""); }else{ System.out.println("=========库存不足========"); } }else { //key已加锁，稍后重试 throw new MyException(); } }catch(Exception e){ e.printStackTrace(); System.out.println("=========程序异常，请重新操作========="); }finally { //释放锁 System.out.println("========锁释放成功======="); redisTemplate.delete(lockKey); } }else{ //key已加锁，稍后重试 throw new MyException(); } } }