5，jedis連接池

 JedisPoolConfig conf = new JedisPoolConfig();
        conf.setMaxWaitMillis(3000);
        conf.setFairness(false);
        conf.setMaxIdle(5);
        conf.setMaxTotal(10);
        JedisPool jedisPool = new JedisPool(conf, "hadoop1", 6379, 100, "xxx");
        int numActive = jedisPool.getNumActive();
        System.out.println("numActive :" + numActive);
        Jedis jedis = jedisPool.getResource();
        jedis.select(0);
        String value = jedis.get("k1");
        System.out.println(value);
        jedisPool.close();