小编给大家分享一下Redis分布式锁的示例分析，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！

第一版本:

@Overridepublic<T>Longset(Stringkey,Tvalue,LongcacheSeconds){if(valueinstanceofHashMap){BoundHashOperationsvalueOperations=redisTemplate.boundHashOps(key);valueOperations.putAll((Map)value);valueOperations.expire(cacheSeconds,TimeUnit.SECONDS);}else{//使用map存储BoundHashOperationsvalueOperations=redisTemplate.boundHashOps(key);valueOperations.put(key,value);//秒valueOperations.expire(cacheSeconds,TimeUnit.SECONDS);}returnnull;}@Overridepublicvoiddel(Stringkey){redisTemplate.delete(key);}

采用set 和 del 完成锁的占用与释放,后经测试得知,set不是线程安全,在并发情况下常常会导致数据不一致.

第二版本:

/***分布式锁*@paramrange锁的长度允许有多少个请求抢占资源*@paramkey*@return*/publicbooleangetLock(intrange,Stringkey){ValueOperations<String,Integer>valueOper1=template.opsForValue();returnvalueOper1.increment(key,1)<=range;}/***初始化锁,设置等于0*@paramkey*@paramexpireSeconds*@return*/publicvoidinitLock(Stringkey,LongexpireSeconds){ValueOperations<String,Integer>operations=template.opsForValue();template.setKeySerializer(newGenericJackson2JsonRedisSerializer());template.setValueSerializer(newGenericJackson2JsonRedisSerializer());operations.set(key,0,expireSeconds*1000);}/***释放锁*@paramkey*/publicvoidreleaseLock(Stringkey){ValueOperations<String,Integer>operations=template.opsForValue();template.setKeySerializer(newGenericJackson2JsonRedisSerializer());template.setValueSerializer(newGenericJackson2JsonRedisSerializer());template.delete(key);}

采用redis的 increament操作完成锁的抢占.但是释放锁时,是每个线程都可以删除redis中的key值. 并且initLock会降上一次的操作给覆盖掉，所以也废弃掉此方法

最终版本:

importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.data.redis.connection.RedisConnectionFactory;importorg.springframework.data.redis.connection.jedis.JedisConnection;importorg.springframework.stereotype.Service;importorg.springframework.util.ReflectionUtils;importredis.clients.jedis.Jedis;importjava.lang.reflect.Field;importjava.util.Collections;@ServicepublicclassRedisLock{privatestaticfinalStringLOCK_SUCCESS="OK";privatestaticfinalStringSET_IF_NOT_EXIST="NX";privatestaticfinalStringSET_WITH_EXPIRE_TIME="PX";privatestaticfinalLongRELEASE_SUCCESS=1L;@AutowiredprivateRedisConnectionFactoryconnectionFactory;/***尝试获取分布式锁*@paramlockKey锁*@paramrequestId请求标识*@paramexpireTime超期时间*@return是否获取成功*/publicbooleanlock(StringlockKey,StringrequestId,intexpireTime){FieldjedisField=ReflectionUtils.findField(JedisConnection.class,"jedis");ReflectionUtils.makeAccessible(jedisField);Jedisjedis=(Jedis)ReflectionUtils.getField(jedisField,connectionFactory.getConnection());Stringresult=jedis.set(lockKey,requestId,SET_IF_NOT_EXIST,SET_WITH_EXPIRE_TIME,expireTime);if(LOCK_SUCCESS.equals(result)){returntrue;}returnfalse;}/***释放分布式锁*@paramlockKey锁*@paramrequestId请求标识*@return是否释放成功*/publicbooleanreleaseLock(StringlockKey,StringrequestId){Stringscript="ifredis.call('get',KEYS[1])==ARGV[1]thenreturnredis.call('del',KEYS[1])elsereturn0end";Objectresult=getJedis().eval(script,Collections.singletonList(lockKey),Collections.singletonList(requestId));if(RELEASE_SUCCESS.equals(result)){returntrue;}returnfalse;}publicJedisgetJedis(){FieldjedisField=ReflectionUtils.findField(JedisConnection.class,"jedis");ReflectionUtils.makeAccessible(jedisField);Jedisjedis=(Jedis)ReflectionUtils.getField(jedisField,connectionFactory.getConnection());returnjedis;}}

以上是“Redis分布式锁的示例分析”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注亿速云行业资讯频道！