PHP防盗链外部资源下载处理类

/**
 *
 * 防盗链外部资源下载处理类
 */
class BurglarDow{
	/**
     * 初始许可下载状态
     * @var    allow
     * @access private
     */
	private $allow      =  false;
	/**
     * 初始下载地址
     * @var    dowUrl
     * @access private
     */
	private $dowUrl     =  null;
	/**
     * 初始来路域名
     * @var    RemoteUrl
     * @access private
     */
	private $RemoteUrl  =  null;
	/**
     * 初始许可资源取用域名列表
     * @var    allowUrl
     * @access private
     */
	private $allowUrl   =  array();
	/**
     * 初始转跳地址
     * @var    Location
     * @access private
     */
	private $Location   =  null;

	public function __construct($dowUrl,$Location,array $allowUrl){
		// 初始下载地址
		$this->dowUrl   = $dowUrl;
		// 初始许可资源取用域名列表
		$this->allowUrl = $allowUrl;
		// 初始转跳地址
		$this->Location = $Location;

		$this->RemoteUrl = @parse_url($_SERVER['HTTP_REFERER']);                                                      // 获取来路域名
		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)){                                                   // 判断是否来至许可域名
				$this->allow  = true;                                                                                 // 下载许可状态为：真
			}
		}
		unset($this->allowUrl,$this->RemoteUrl);                                                                      // 释放内存变量
	}

	/**
	 * 防盗链资源下载
	 * @access public
	 * @return mixed
	 */
	public function dow(){
		$FileInfo = get_headers($this->dowUrl,1);                                                                     // 获取远程文件头部信息

		if(true === $this->allow){                                                                                    // 判断是否许可下载资源
			//判断配置文件是否存在
			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']}";
				$handle = fopen ('Config.ini', "wb");                                                                 // Config.ini文件不存在则创建文件
				if (fwrite ($handle, $FileConStr) == FALSE) {                                                         // 数据写入文件 
					echo "File creation failed ..."; 
				}
				fclose ($handle);                                                                                     // 关闭一个已打开的文件指针
				$FileCon = parse_ini_file('Config.ini');
			}
			if(!empty($$this->dowUrl)){
				$fp = @fopen($$this->dowUrl, "rb");                                                                   // 二进制模式读取文件
				if (!$fp)
					 exit("Download a mistake.\n\n");

				// 输出远程资源
				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($fp)){
					set_time_limit(0);                                                                                 // 设置文件最长执行时间
					echo fread($fp, 1024);                                                                             // 输出文件
					flush();                                                                                           // 输出缓冲
					ob_flush();                                                                                        // 输出缓冲区中的内容
				}
				fclose($fp);
			}else{
				header("HTTP/1.1 404 Not Found");
			}
		}else{
			header("HTTP/1.1 301 Moved Permanently");
			header("Location: ".$this->Location);
		}
	}
}
// 远程资源地址
$dowUrl = 'http://dldir1.qq.com/qqfile/qq/QQ5.1/10055/QQ5.1.exe';
// 转跳地址
$Location = 'http://www.scutephp.com';
// 许可来路域名列表
$allowUrl = array(
	'blog.emtalk.net',
);
$BurglarDow = new BurglarDow($dowUrl,$Location,$allowUrl);
$BurglarDow -> dow();