<?php

class Sdownload
{
    private $mDownStart;
    
    private $mFileSize;
    
    private $mFileHandle;
    
    private $mFilePath;
    
    private $mFileName;
    
    /***
     * @access public
     * @return roid
     */
    public function __construct()
    {}
    
    /*
     * 下载
     * $param string @pFilePath
     * @param string @pFileName
     * @access public
     * @return void
     */
    public function Down($pFilePath,$pFileName = '')
    {
        //echo $pFilePath;
        
        $this->mFilePath = $pFilePath;
        
        if(!$this->IniFile()) 
        {
            $this->SendError();
        }
        
        $this->mFileName = empty($pFileName) ? $this->GetFileName() : $pFileName;
        //echo $this->mFileName;
        //exit;
        //$this->IniFile();
        $this->SetStart();
        
        $this->SetHeader();
        
        $this->Send();
    }
    
    /*
     * 初始化文件
     * 
     */
    private function IniFile()
    {
        
        if(!is_file($this->mFilePath)) 
        {
            return false;
        }
        
        $this->mFileHandle = fopen($this->mFilePath, 'rb');
        $this->mFileSize = filesize($this->mFilePath);
        
        return true;
    }
    
    /*
     * 设置下载开始点
     */
    private function SetStart()
    {
        if(!empty($_SERVER['HTTP_RANGE']) && preg_match("/^bytes=([\d]?)-([\d]?)$/i",$_SERVER['HTTP_RANGE'],$match))
        {
            if(empty($match[1])) 
            {
                $this->mDownStart = $match[1];
            }
            
            fseek($this->mFileHandle, $this->mDownStart);
        }
        else{
            $this->mDownStart = 0;
        }
    }
    
    /*
     * 设置http头
     */
    private function SetHeader()
    {
        
        header("Cache-control: public");
        header("Pragma: public");
        header("Content-Length: ".($this->mFileSize - $this->mDownStart));
        
        if($this->mDownStart > 0)
        {
            Header("HTTP/1.1 206 Partial Content");
            Header("Content-Ranges: bytes" . $this->mDownStart ."-". ($this->mFileSize -1) ."/". $this->mFileSize);
        }
        else{
            header("Accept-Ranges: bytes");
        }
        
        header( "Accept-Length: ".$this->mFileSize); 
    
        //header( "Content-type:application/octet-stream "); 
        header("Content-Type: application/octer-stream");
        //header("Content-Type: application/zip");
        header("Content-Disposition: attachment;filename=" .$this->mFileName);
        
    }
    
    /*
     * 获取全路径里的文件名部分
     */
    private function GetFileName()
    {
        return basename($this->FilePath);
    }
    
    /*
     * 发送数据
     */
    private function Send()
    {
        //readfile($this->FileHandle);
        //echo $this->mFileHandle;
        fpassthru($this->mFileHandle);
    }
    
    /*
     * 发送错误
     */
    public function SendError()
    {
        @header("HTTP/1.0 404 Not Found");
        @header("Status: 404 Not Found");
        exit();
    }
}

error_reporting(E_ALL | E_STRICT);
        require_once(ROOT_PATH .'/framework/helper/download.class.php');
        //echo '1--1=';
        //echo file_exists("/home/www/test/zhangyf/newbook/". $this->filename).'1--1';
        //建文件下载对象
        $sd = new Sdownload();
        
        $this->path = "/home/www/test/zhangyf/newbook/". $this->filename;
        //echo $this->path;
        //echo $this->filename;
        $sd->Down($this->path, $this->filename);