@Override
	public User hasUser(User user) {
		// 首先判断用户名是否存在
		if (!hasUserName(user.getUserName())) {
			return null;
		}
		ShardedJedis jedis =  getConnection(); 
		// 获取用户名对于的userid
		String key = prefix + user.getUserName() + ":userid";
		String userId = jedis.get(key);
		// 判断用户密码是否匹配
		key = prefix + userId + ":password";
		String password = jedis.get(key);
		if (!password.equals(user.getPassword())) {
			returnConnection(jedis);
			return null;
		}
		// 获取用户其他信息，比如email
		key = prefix + userId + ":email";
		String email = jedis.get(key);
		
		returnConnection(jedis);
		return new User(Integer.parseInt(userId), user.getUserName(), "", email);
	}