Redis递增递减功能

递增指令：incr（默认从0开始）

递减指令：decr（默认从0开始，递减会出现负数，这点跟memcache不一样,mc到0）

如下：

附上shardedJedisPool和JedisCluster的两种实现方式：

shardedJedisPool：

@Override
    public Long decr(String key) {
        ShardedJedis jedis = null;
        Long result = 0l;
        try {
            jedis =  shardedJedisPool.getResource();
            result = jedis.decr(key);
        } catch (Exception e) {
            log.error("redis decr error and key = " + key, e);
        }
        return result;
    }

    @Override
    public Long incr(String key) {
        ShardedJedis jedis = null;
        Long result = 0l;
        try {
            jedis =  shardedJedisPool.getResource();
            result = jedis.incr(key);
        } catch (Exception e) {
            log.error("redis incr error and key = " + key, e);
        }
        return result;
    }

JedisCluster：

@Override
    public Long decr(String key) {
        Long result = 0l;
        try {
            result = jedisCluster.decr(key);
        } catch (Exception e) {
            log.error("jedisCluster decr error and key = " + key, e);
        }
        return result;
    }

    @Override
    public Long incr(String key) {
        Long result = 0l;
        try {
            result = jedisCluster.incr(key);
        } catch (Exception e) {
            log.error("jedisCluster incr error and key = " + key, e);
        }
        return result;
    }