How to get/set the language class of the user access page through php

<?php
/** User Language Class 获取/设置用户访问的页面语言，如果用户没有设置访问语言，则读取Accept-Language
*   Date:   2014-05-26
*   Author: fdipzone
*   Ver:    1.0
*
*   Func:
*   public  get               获取用户访问语言
*   public  set               设置用户访问语言
*   private getAcceptLanguage 获取HTTP_ACCEPT_LANGUAGE
*/
class UserLang{ // class start
    private $name = &#39;userlang&#39;; // cookie name
    private $expire = 2592000;  // cookie expire 30 days
    /** 初始化
    * @param String $name   cookie name
    * @param int    $expire cookie expire
    */
    public function __construct($name=&#39;&#39;, $expire=null){
        // 设置cookie name
        if($name!=&#39;&#39;){
            $this->name = $name;
        }
        // 设置cookie expire
        if(is_numeric($expire) && $expire>0){
            $this->expire = intval($expire);
        }
    }
    /** 获取用户访问语言 */
    public function get(){
        // 判断用户是否有设置过语言
        if(isset($_COOKIE[$this->name])){
            $lang = $_COOKIE[$this->name];
        }else{
            $lang = $this->getAcceptLanguage();
        }
        return $lang;
    }
    /** 设置用户访问语言
    * @param String $lang 用户访问语言
    */
    public function set($lang=&#39;&#39;){
        $lang = strtolower($lang);
        // 只能是英文，简体中文，繁体中文
        if(in_array($lang, array(&#39;en&#39;,&#39;sc&#39;,&#39;tc&#39;))){
            setcookie($this->name, $lang, time()+$this->expire);
        }
    }
    /** 获取HTTP_ACCEPT_LANGUAGE */
    private function getAcceptLanguage(){
        $lang = strtolower($_SERVER[&#39;HTTP_ACCEPT_LANGUAGE&#39;]);
        if(in_array(substr($lang,0,5), array(&#39;zh-tw&#39;,&#39;zh_hk&#39;))){
            $lang = &#39;tc&#39;;
        }elseif(in_array(substr($lang,0,5), array(&#39;zh-cn&#39;,&#39;zh-sg&#39;))){
            $lang = &#39;sc&#39;;
        }else{
            $lang = &#39;en&#39;;
        }
        return $lang;
    }
} // class end
?>

<?php
require "UserLang.class.php";
$obj = new UserLang(&#39;sitelang&#39;, 3600);
echo $obj->get().&#39;<br>&#39;;
?>

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