redis 并发锁

public static void main(String[] args) {
       String value = UUID.randomUUID() + ":" + Thread.currentThread().getName();
       long tryTime = 100000L;
       long expireTime = 100000L;
       String key = "lock";
       JedisPool jedisPool = new JedisPool();
       Jedis jedis = jedisPool.getResource();
       for (int i = 0; i < 10; i++) {
           System.out.println(getlock(jedis, key, value, tryTime, expireTime));
       }
       for (int i = 0; i < 10; i++) {
           System.out.println(releaseLock(jedis, key, value, tryTime));
       }
   }

/**
 *
 * @param jedis
 * @param key key
 * @param value 重如锁value
 * @param tryTime 重试时间
 * @return result
 */
   private static Object releaseLock(Jedis jedis, String key, String value, long tryTime) {
       String script = "if (redis.call(‘exists‘, KEYS[1]) == 0) then " +
               "return 0;" +
               "end;" +
               "if(redis.call(‘hexists‘, KEYS[1], ARGV[1]) == 1) then " +
               "local lo = redis.call(‘hincrby‘,KEYS[1],ARGV[1], -1)" +
               "if(lo < 1) then " +
               "redis.call(‘del‘, KEYS[1]);" +
               "return lo;" +
               "end;" +
               "return lo;" +
               "end;" +
               "return -1;";
   final long endTime = tryTime + System.currentTimeMillis();
   while (true) {
      Object res =  jedis.eval(script, Collections.singletonList(key), Collections.singletonList(value));
      if (Integer.parseInt(String.valueOf(res)) >= 0) {
         return true;
      }
      if (System.currentTimeMillis() - endTime > 0) {
         return false;
      }
      try {
         TimeUnit.SECONDS.sleep(1);
      } catch (InterruptedException e) {
         System.out.println("sleep error");
      }
   }
   }

/**
 *
 * @param jedis
 * @param key key
 * @param value 重如锁value
 * @param tryTime 重试时间
 * @param expireTime key过期时间
 * @return result
 */
   private static boolean getlock(Jedis jedis, String key, String value, long tryTime, long expireTime) {
       final long endTime = tryTime + System.currentTimeMillis();
       String script = "if (redis.call(‘exists‘, KEYS[1]) == 0) then " +
               "redis.call(‘hset‘, KEYS[1], ARGV[1], 1);" +
               "redis.call(‘pexpire‘, KEYS[1], ARGV[2]);" +
               "return 1;" +
               "end;" +
               "if(redis.call(‘hexists‘, KEYS[1], ARGV[1]) == 1) then " +
               "redis.call(‘pexpire‘, KEYS[1], ARGV[2]);" +
               "return redis.call(‘hincrby‘,KEYS[1],ARGV[1],1);" +
               "end;" +
               "return 0;";
       while (true) {
      Object res = jedis.eval(script, Collections.singletonList(key), Arrays.asList(value, expireTime+""));
      if (Integer.parseInt(String.valueOf(res)) > 0) {
         return true;
      }
      if (System.currentTimeMillis() - endTime > 0) {
         return false;
      }
      try {
         TimeUnit.SECONDS.sleep(1);
      } catch (InterruptedException e) {
         System.out.println("sleep error");
      }
   }
   }

redis 并发锁

原文：https://www.cnblogs.com/wushenghfut/p/14883383.html