redis操作hash set，每次都插入乱码空键，什么原因？

这个是查看到的数据，每次插入hash的时候都会出现最后一个乱码key，并且value是空

public void setHashVal(final String key , final Map<String, String> map){
        redisTemplate.execute(new RedisCallback<Object>() {
            @Override
            public Object doInRedis(RedisConnection connection)
                    throws DataAccessException {
                byte[] param = redisTemplate.getStringSerializer().serialize(key);
                if(connection.exists(param)){
                    connection.del(param);
                }
                BoundHashOperations<Serializable, byte[], byte[]> boundHashOperations = redisTemplate.boundHashOps(param);
                Set<String> keySet = map.keySet();
                for (String mapKey : keySet) {
                    boundHashOperations.put(redisTemplate.getStringSerializer().serialize(mapKey),
                            redisTemplate.getStringSerializer().serialize(mapKey));
                }
                connection.hMSet(param, boundHashOperations.entries());  
                return null;
            }
        });
    }

这个是插入的代码，帮忙看看哪里会问题。或者是什么原因造成的