Java Code Examples for redis.clients.jedis.Jedis#eval()

/**
 * Redis 限流
 */
public static Boolean limit() {
    Jedis jedis = null;
    Object result = null;
    try {
        // 获取 jedis 实例
        jedis = RedisPool.getJedis();
        // 解析 Lua 文件
        String script = ScriptUtil.getScript("limit.lua");
        // 请求限流
        String key = String.valueOf(System.currentTimeMillis() / 1000);
        // 计数限流
        result = jedis.eval(script, Collections.singletonList(key), Collections.singletonList(String.valueOf(limit)));
        if (FAIL_CODE != (Long) result) {
            log.info("成功获取令牌");
            return true;
        }
    } catch (Exception e) {
        log.error("limit 获取 Jedis 实例失败：", e);
    } finally {
        RedisPool.jedisPoolClose(jedis);
    }
    return false;
}
 

private String createRedisKey(String lockId) {
    Jedis jedis = null;
    //boolean broken = false;
    try {
        String value=lockId+randomId(1);
        jedis = jedisPool.getResource();
        String luaScript = ""
                + "\nlocal r = tonumber(redis.call('SETNX', KEYS[1],ARGV[1]));"
                + "\nredis.call('PEXPIRE',KEYS[1],ARGV[2]);"
                + "\nreturn r";
        List<String> keys = new ArrayList<String>();
        keys.add(lockId);
        List<String> args = new ArrayList<String>();
        args.add(value);
        args.add(lockTimeout+"");
        Long ret = (Long) jedis.eval(luaScript, keys, args);
        if( new Long(1).equals(ret)){
            return value;
        }
    }finally {
        if(jedis!=null) jedis.close();
    }
    return null;
}
 

void unlockRedisLock(String key,String value) {
    Jedis jedis = null;
    //boolean broken = false;
    try {
        jedis = jedisPool.getResource();
        String luaScript=""
                +"\nlocal v = redis.call('GET', KEYS[1]);"
                +"\nlocal r= 0;"
                +"\nif v == ARGV[1] then"
                +"\nr =redis.call('DEL',KEYS[1]);"
                +"\nend"
                +"\nreturn r";
        List<String> keys = new ArrayList<String>();
        keys.add(key);
        List<String> args = new ArrayList<String>();
        args.add(value);
        /*Object r=*/jedis.eval(luaScript, keys, args);
    } finally {
        if(jedis!=null) jedis.close();
    }
}
 

void unlockRedisLock(String key,String value) {
    Jedis jedis = null;
    boolean broken = false;
    try {
        jedis = jedisPool.getResource();
        String luaScript=""
                +"\nlocal v = redis.call('GET', KEYS[1]);"
                +"\nlocal r= 0;"
                +"\nif v == ARGV[1] then"
                +"\nr =redis.call('DEL',KEYS[1]);"
                +"\nend"
                +"\nreturn r";
        List<String> keys = new ArrayList<String>();
        keys.add(key);
        List<String> args = new ArrayList<String>();
        args.add(value);
        Object r=jedis.eval(luaScript, keys, args);
    } finally {
        if(jedis!=null) jedis.close();
    }
}
 

private String createRedisKey(String lockId) {
    Jedis jedis = null;
    boolean broken = false;
    try {
        String value=lockId+randomId(1);
        jedis = jedisPool.getResource();
        String luaScript = ""
                + "\nlocal r = tonumber(redis.call('SETNX', KEYS[1],ARGV[1]));"
                + "\nredis.call('PEXPIRE',KEYS[1],ARGV[2]);"
                + "\nreturn r";
        List<String> keys = new ArrayList<String>();
        keys.add(lockId);
        List<String> args = new ArrayList<String>();
        args.add(value);
        args.add(lockTimeout+"");
        Long ret = (Long) jedis.eval(luaScript, keys, args);
        if( new Long(1).equals(ret)){
            return value;
        }
    }finally {
        if(jedis!=null) jedis.close();
    }
    return null;
}
 

private boolean doPeriod(Jedis jedis, String keyPrefix, int permitsPerUnit) {
    List<String> jedisTime = jedis.time();
    long currentSecond = Long.parseLong(jedisTime.get(0));
    long microSecondsElapseInCurrentSecond = Long.parseLong(jedisTime.get(1));
    String[] keyNames = getKeyNames(currentSecond, keyPrefix);
    //因为redis访问实际上是单线程的，而且jedis.time()方法返回的时间精度为微秒级，每一个jedis.time()调用耗时应该会超过1微秒，因此我们可以认为每次jedis.time()返回的时间都是唯一且递增
    //因此这个currentTimeInMicroSecond在多线程情况下不会存在相同
    long currentTimeInMicroSecond = currentSecond * 1000000 + microSecondsElapseInCurrentSecond;
    String previousSectionBeginScore = String.valueOf((currentTimeInMicroSecond - getPeriodMicrosecond()));
    String expires =String.valueOf(getExpire());
    String currentTimeInMicroSecondStr = String.valueOf(currentTimeInMicroSecond);
    List<String> keys = new ArrayList<String>();
    keys.add(keyNames[0]);
    keys.add(keyNames[1]);
    List<String> argvs = new ArrayList<String>();
    argvs.add(currentTimeInMicroSecondStr);
    argvs.add(currentTimeInMicroSecondStr);
    argvs.add(previousSectionBeginScore);
    argvs.add(expires);
    argvs.add(String.valueOf(permitsPerUnit));
    Long val = (Long)jedis.eval(LUA_PERIOD_SCRIPT, keys, argvs);
    return (val > 0);
}
 

@Override
long queryWaitMicros(int permits, Long timeoutMicros) {
    List<String> keys = Arrays.asList(key, String.valueOf(maxPermits), String.valueOf(permitsPerSecond));
    List<String> args = new ArrayList<>();
    args.add(String.valueOf(permits));
    if (timeoutMicros != null) {
        args.add(String.valueOf(timeoutMicros));
    }
    try {
        Jedis redis = getJedis();
        Object result = redis.eval(script, keys, args);
        return (long) result;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return 0;
}
 

/**
 * 释放分布式锁
 *
 * @param lockKey   锁
 * @param requestId 请求标识
 * @return 是否释放成功
 */
public static boolean releaseDistributedLock(String lockKey, String requestId) {
    Jedis redis = null;
    try {
        redis = getJedis();
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        Object result = redis.eval(script, Collections.singletonList(lockKey), Collections.singletonList(requestId));
        if (RELEASE_SUCCESS.equals(result)) {
            return true;
        }
        return false;
    } finally {
        if (redis != null) {
            redis.close();
        }
    }
}
 

public Boolean acquire(int permits) throws Exception {
    Jedis redis = getJedis();
    Object result = redis.eval(script,
            Arrays.asList(key, String.valueOf(maxPermits), String.valueOf(intervalMilliseconds)),
            Arrays.asList(String.valueOf(permits))
    );
    if (result != null && 0 != (Long) result) {
        return true;
    } else {
        return false;
    }
}
 

public Object jEval(String script, String scriptsha1, int argcount, String... args) throws JedisException {
  Jedis jedis = getJedis();
  try {
    return jedis.evalsha(scriptsha1, argcount, args);
  } catch (JedisNoScriptException e) {
    if (DEBUG) {
      Log.d(LOG_TAG, "Got a JedisNoScriptException for " + scriptsha1);
    }
    // This happens if the server doesn't have the script loaded
    // So we use regular eval, which should then cache the script
    return jedis.eval(script, argcount, args);
  }
}
 

/**
 * Eval lua script command
 *
 * @param script
 * @param keys
 * @param args
 * @return
 */
public Object eval(String script, List<String> keys, List<String> args) {
    Jedis jedis = null;
    try {
        jedis = jedisPool.getResource();
        return jedis.eval(script, keys, args);

    } finally {
        if (jedis != null) {
            jedis.close();
        }
    }
}
 

/**
 * lua脚本释放分布式锁
 * @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) {
    // 首先获取锁对应的value值，检查是否与requestId相等，如果相等则删除锁（解锁）
    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;

}
 

public boolean acquire() {
	String key = String.valueOf(System.currentTimeMillis() / 1000);
	Jedis jedis = pool.getResource();
	try {
		Object result = jedis.eval(script, Lists.newArrayList(key), Lists.newArrayList(limit));
		if ((Long) result != 0) {
			return true;
		}
	} catch (Exception e) {
		System.err.println(e.getStackTrace());
	} finally {
		jedis.close();
	}
	return false;
}
 

public boolean acquire(String keyPrefix, int permitsPerUnit){
    boolean rtv = false;
    if (jedisPool != null) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            if (timeUnit == TimeUnit.SECONDS) {
                String keyName = getKeyNameForSecond(jedis, keyPrefix);

                List<String> keys = new ArrayList<String>();
                keys.add(keyName);
                List<String> argvs = new ArrayList<String>();
                argvs.add(String.valueOf(getExpire()));
                argvs.add(String.valueOf(permitsPerUnit));
                Long val = (Long)jedis.eval(LUA_SECOND_SCRIPT, keys, argvs);
                rtv = (val > 0);

            } else if (timeUnit == TimeUnit.MINUTES || timeUnit == TimeUnit.HOURS || timeUnit == TimeUnit.DAYS) {
                rtv = doPeriod(jedis, keyPrefix, permitsPerUnit);
            }
        } finally {
            if (jedis != null) {
                jedis.close();
            }
        }
    }
    return rtv;
}
 

public boolean unlock(String key, String value) {
    Jedis jedis = jedisPool.getResource();

    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(LOCK_PREFIX + key), Collections.singletonList(value));

    jedis.close();
    return UNLOCK_MSG.equals(result);
}
 

public static void flushKeySpace(Jedis jedis, String pattern) {
  jedis.eval(
      "for i, k in ipairs(redis.call('keys', '" + pattern + "')) do redis.call('del', k); end");
}
 

private Object eval0(Jedis j, String script, List<String> keys, List<String> args) {
	return j.eval(script, keys, args);
}
 

/**
 * 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));
    return RELEASE_SUCCESS.equals(result);
}