PHP寫的資源下載防盜鏈類分享

這幾天在寫一個PHP防盜鏈外部資源下載處理函數，昨天晚上剛完成編寫，中間遇到了些問題，這裡就不詳述了；
以下是自寫的簡單的PHP防盜鏈處理類(重新整理編寫成類文件，以便後期改進)；

復制代碼 代碼如下:
<?php
/**
 *
 * 防盜鏈外部資源下載處理類
 *
 * @link   http://jb51.net
 *
 */
class BurglarDow{
 /**
     * 初始許可下載狀態
     * @var    allow
     * @access private
     */
 private $allow      =  false;
 /**
     * 初始下載地址
     * @var    dowUrl
     * @access private
     */
 private $dowUrl     =  null;
 /**
     * 初始來路域名
     * @var    RemoteUrl
     * @access private
     */
 private $RemoteUrl  =  null;
 /**
     * 初始許可資源取用域名列表
     * @var    allowUrl
     * @access private
     */
 private $allowUrl   =  array();
 /**
     * 初始轉跳地址
     * @var    Location
     * @access private
     */
 private $Location   =  null;

 public function __construct($dowUrl,$Location,array $allowUrl){
  // 初始下載地址
  $this->dowUrl   = $dowUrl;
  // 初始許可資源取用域名列表
  $this->allowUrl = $allowUrl;
  // 初始轉跳地址
  $this->Location = $Location;

  $this->RemoteUrl = @parse_url($_SERVER['HTTP_REFERER']);                                                      // 獲取來路域名
  if(!is_array($this->RemoteUrl))
   header("HTTP/1.1 301 Moved Permanently");
   header("Location: ".$this->Location);

  if(isset($this->RemoteUrl['host'])){
   if(in_array($this->RemoteUrl['host'],$this->allowUrl)){                                                   // 判斷是否來至許可域名
    $this->allow  = true;                                                                                 // 下載許可狀態為：真
   }
  }
  unset($this->allowUrl,$this->RemoteUrl);                                                                      // 釋放內存變量
 }

 /**
  * 防盜鏈資源下載
  * @access public
  * @return mixed
  */
 public function dow(){
  $FileInfo = get_headers($this->dowUrl,1);                                                                     // 獲取遠程文件頭部信息

  if(true === $this->allow){                                                                                    // 判斷是否許可下載資源
   //判斷配置文件是否存在
   if(is_file('Config.ini')){
    $FileCon = parse_ini_file('Config.ini');
   }else{
    $FileName   =  basename($FileInfo['Content-Location']);
    $FileConStr = "FileName  = {$FileName}\r\nFileUrl   = {$FileInfo['Content-Location']}\r\nFileSize   = {$FileInfo['Content-Length']}";
    $handle = fopen ('Config.ini', "wb");                                                                 // Config.ini文件不存在則創建文件
    if (fwrite ($handle, $FileConStr) == FALSE) {                                                         // 數據寫入文件
     echo "File creation failed ...";
    }
    fclose ($handle);                                                                                     // 關閉一個已打開的文件指針
    $FileCon = parse_ini_file('Config.ini');
   }
   if(!empty($$this->dowUrl)){
    $fp = @fopen($$this->dowUrl, "rb");                                                                   // 二進制模式讀取文件
    if (!$fp)
      exit("Download a mistake.\n\n");

    // 輸出遠程資源
    header("Content-type:text/html;charset=utf-8");
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename='.$FileCon['FileName']);
    header("Accept-Ranges: bytes");
    header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control:must-revalidate,post-check=0,pre-check=0');
    header('Pragma: public');
    header('Content-Length: '.$FileCon['FileSize']);
    while (!feof($fp)){
     set_time_limit(0);                                                                                 // 設置文件最長執行時間
     echo fread($fp, 1024);                                                                             // 輸出文件
     flush();                                                                                           // 輸出緩沖
     ob_flush();                                                                                        // 輸出緩沖區中的內容
    }
    fclose($fp);
   }else{
    header("HTTP/1.1 404 Not Found");
   }
  }else{
   header("HTTP/1.1 301 Moved Permanently");
   header("Location: ".$this->Location);
  }
 }
}
// 遠程資源地址
$dowUrl = 'http://dldir1.qq.com/qqfile/qq/QQ5.1/10055/QQ5.1.exe';
// 轉跳地址
$Location = 'http://jb51.net';
// 許可來路域名列表
$allowUrl = array(
 'jb51.net',
);
$BurglarDow = new BurglarDow($dowUrl,$Location,$allowUrl);
$BurglarDow -> dow();