/**        
        * gb2312转换utf8编码
        * @param $str
        * @return mixed
        */
        public static function gb2utf($str)
        {
            return iconv("gb2312","utf-8//IGNORE",$str);
        }

        /**        
        * utf8转换gb2312编码
        * @param $str
        * @return mixed
        */
        public static function utfgb2($str)
        {
            return iconv("utf-8","gb2312//IGNORE",$str);
        }