content: package org.zeus.common.util;
  
  import redis.clients.jedis.Jedis;
  
  import java.util.Collections;
  
  /**
   * @author: lizhizhong
   * CreatedDate: 2018/12/6.
   */
  public class RedisTool {
  
      private static final String LOCK_SUCCESS = "OK";
      private static final String SET_IF_NOT_EXIST = "NX";
      private static final String SET_WITH_EXPIRE_TIME = "PX";
  
      private static final Long RELEASE_SUCCESS = 1L;
  
      /**
       * 尝试获取分布式锁
       * @param jedis Redis客户端
       * @param lockKey 锁
       * @param requestId 请求标识
       * @param expireTime 超期时间
       * @return 是否获取成功
       */
      public static boolean tryGetDistributedLock(Jedis jedis, String lockKey, String requestId, int expireTime) {
  
          String result = jedis.set(lockKey, requestId, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, expireTime);
  
          if (LOCK_SUCCESS.equals(result)) {
              return true;
          }
          return false;
  
      }
  
      /**
       * 释放分布式锁
       * @param jedis Redis客户端
       * @param lockKey 锁
       * @param requestId 请求标识
       * @return 是否释放成功
       */
      public static boolean releaseDistributedLock(Jedis jedis, String lockKey, String requestId) {
  
          String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
          Object result = jedis.eval(script, Collections.singletonList(lockKey), Collections.singletonList(requestId));
  
          if (RELEASE_SUCCESS.equals(result)) {
              return true;
          }
          return false;
  
      }
  
  }
  