php中将字符串转为HTML的实体引用的一个类

代码如下:
class HtmlEncode {
        static $_convertToHtmlEntitiesSrcEncoding='UTF-8';

        /**
         * 将非ASCII字符串转换成HTML实体
         *
         * @example HtmlEncode::encode("我信了"); //输出:我信了
         * @param string $s 要进行编码的字符串
         * @return string 返回HTML实体引用
         */
        public static function encode($s,$srcEncoding='UTF-8') {
            self::$_convertToHtmlEntitiesSrcEncoding=$srcEncoding;
            return preg_replace_callback('|[^\x00-\x7F]+|',array(__CLASS__,'_convertToHtmlEntities'),$s);
        }

        public static function _convertToHtmlEntities($data) {
            if (is_array($data)) {
                $chars=str_split(iconv(self::$_convertToHtmlEntitiesSrcEncoding,"UCS-2BE",$data[0]),2);
                $chars=array_map(array(__CLASS__,__FUNCTION__),$chars);
                return join("",$chars);
            } else {
                $code=hexdec(sprintf("%02s%02s;",dechex(ord($data {0})),dechex(ord($data {1}))));
                return sprintf("&#%s;",$code);
            }
        }     
    }