PHP将字符串转为HTML实体引用

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 $s 要进行编码的字符串
     * @return string 返回HTML实体引用 www.2cto.com
     */ 
    public static function encode($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); 
        } 
    } 
 
}