简单实用的 redis 分布式锁

RedisCallback<Boolean> callback = (connection) -> {    return connection.set(lockKey.getBytes(Charset.forName("UTF-8")), requestId.getBytes(Charset.forName("UTF-8")), Expiration.seconds(timeUnit.toSeconds(expire)), RedisStringCommands.SetOption.SET_IF_ABSENT);};return (Boolean)redisTemplate.execute(callback)

@Slf4jpublic class RedisDistributedLock {   private RedisTemplate redisTemplate;   public RedisDistributedLock(RedisTemplate redisTemplate){    this.redisTemplate = redisTemplate;  }   public static final String UNLOCK_LUA;   /**   * 释放锁脚本，原子操作   */  static {    StringBuilder sb = new StringBuilder();    sb.append("if redis.call(\"get\",KEYS[1]) == ARGV[1] ");    sb.append("then ");    sb.append("    return redis.call(\"del\",KEYS[1]) ");    sb.append("else ");    sb.append("    return 0 ");    sb.append("end ");    UNLOCK_LUA = sb.toString();  }    /**   * 获取分布式锁，原子操作   * @param lockKey   * @param requestId 唯一ID, 可以使用UUID.randomUUID().toString();   * @param expire   * @param timeUnit   * @return   */  public boolean tryLock(String lockKey, String requestId, long expire, TimeUnit timeUnit) {    try{      RedisCallback<Boolean> callback = (connection) -> {        return connection.set(lockKey.getBytes(Charset.forName("UTF-8")), requestId.getBytes(Charset.forName("UTF-8")), Expiration.seconds(timeUnit.toSeconds(expire)), RedisStringCommands.SetOption.SET_IF_ABSENT);      };      return (Boolean)redisTemplate.execute(callback);    } catch (Exception e) {      log.error("redis lock error.", e);    }    return false;  }   /**   * 释放锁   * @param lockKey   * @param requestId 唯一ID   * @return   */  public boolean releaseLock(String lockKey, String requestId) {    RedisCallback<Boolean> callback = (connection) -> {      return connection.eval(UNLOCK_LUA.getBytes(), ReturnType.BOOLEAN ,1, lockKey.getBytes(Charset.forName("UTF-8")), requestId.getBytes(Charset.forName("UTF-8")));    };    return (Boolean)redisTemplate.execute(callback);  }   /**   * 获取Redis锁的value值   * @param lockKey   * @return   */  public String get(String lockKey) {    try {      RedisCallback<String> callback = (connection) -> {        return new String(connection.get(lockKey.getBytes()), Charset.forName("UTF-8"));      };      return (String)redisTemplate.execute(callback);    } catch (Exception e) {      log.error("get redis occurred an exception", e);    }    return null;  } }