<?php
/** php下载类,支持断点续传
* Date: 2013-06-30
* Author: fdipzone
* Ver: 1.0
* edit: ww.jb200.com
* Func:
* download: 下载文件
* setSpeed: 设置下载速度
* getRange: 获取header中Range
*/
class FileDownload{ // class start
private $_speed = 512; // 下载速度
/** 下载
* @param String $file 要下载的
文件路径
* @param String $name 文件名称,为空则与下载的文件名称一样
* @param boolean $reload 是否开启断点续传
*/
public function download($file, $name='', $reload=false){
if(
file_exists($file)){
if($name==''){
$name = basename($file);
}
$fp = fopen($file, 'rb');
$file_size = filesize($file);
$ranges = $this->getRange($file_size);
header('cache-control:public');
header('content-type:application/octet-stream');
header('content-disposition:attachment; filename='.$name);
if($reload && $ranges!=null){ // 使用续传
header('HTTP/1.1 206 Partial Content');
header('Accept-Ranges:bytes');
// 剩余长度
header(sprintf('content-length:%u',$ranges['end']-$ranges['start']));
// range信息
header(sprintf('content-range:bytes %s-%s/%s', $ranges['start'], $ranges['end'], $file_size));
// fp指针跳到断点位置
fseek($fp, sprintf('%u', $ranges['start']));
}else{
header('HTTP/1.1 200 OK');
header('content-length:'.$file_size);
}
while(!feof($fp)){
echo fread($fp, round($this->_speed*1024,0));
ob_flush();
//sleep(1); // 用于测试,减慢下载速度
}
($fp!=null) && fclose($fp);
}else{
return '';
}
}
/** 设置下载速度
* @param int $speed
*/
public function setSpeed($speed){
if(is_numeric($speed) && $speed>16 && $speed<4096){
$this->_speed = $speed;
}
}
/** 获取header range信息
* @param int $file_size 文件大小
* @return Array
*/
private function getRange($file_size){
if(isset($_SERVER['HTTP_RANGE']) && !empty($_SERVER['HTTP_RANGE'])){
$range = $_SERVER['HTTP_RANGE'];
$range = preg_replace('/[s|,].*/', '', $range);
$range = explode('-', substr($range, 6));
if(count($range)<2){
$range[1] = $file_size;
}
$range = array_combine(array('start','end'), $range);
if(empty($range['start'])){
$range['start'] = 0;
}
if(empty($range['end'])){
$range['end'] = $file_size;
}
return $range;
}
return null;
}
} // class end
?>
<?php
require('FileDownload.class.php');
$file = 'book.zip';
$name = time().'.zip';
$obj = new FileDownload();
$flag = $obj->download($file, $name);
//$flag = $obj->download($file, $name, true); // 断点续传
if(!$flag){
echo 'file not exists';
}
?>
