php文件下载

<?php
    
    /*
    *下载报告
    */
    public function down_report(){
        /*
        $result = array("error"=>1,"content"=>'');
        if(!session('user_id')) {
            $result['error'] = -1;
            $result['content'] = "请先登录";
            $result['url'] = "/mobile/user/login";
            $this->showMsg($result);
        }
        $url = yf_empty($_POST['url'], '', true);
        if(!$url) {
            $result['content'] = "非法参数";
            $this->showMsg($result);
        }
        */
　　　　/*        
        if(1==1){
            $result['error'] = 1;
            $result['content'] = $url;
            $this->showMsg($result);
        }
　　　　*/
        
        
        /* 下载开始 */
        $url = yf_empty($_GET['url'], '', true);
        if(!$url){
            echo "文件参数错误";
            exit;
        }
        $filename = basename($url);    //文件名
        $filepath = $_SERVER['DOCUMENT_ROOT'].$url;    //文件绝对路径
       
        if(!file_exists($filepath)){
           $result['error'] = 1;
           $result['content'] = "文件不存在";
        }
       
        $fp = fopen($filepath,"r+");        //打开文件流
        $filesize = filesize($filepath);
       
        //$filearr = explode(".",$filename);
        //$prefix = $filearr[0];    //文件前缀
        //$suxfix = $filearr[1];    //文件后缀
        header("Content-Type:application/octet-stream");
        header("Accept-Ranges:bytes");
        header("Accept-Length:".$filesize);
        header("Content-Disposition:attachment;filename=".$filename);
        header("Pragma:no-cache");    //不缓存
        header("Expires:0");
        $buffer=1024;
        $filecount=0;
       
        //向浏览器返回数据
        while(!feof($fp) && $filecount<$filesize){
           $filecon = fread($fp,$buffer);
           $filecount += $buffer;
           echo $filecon;
        }
        fclose($fp);
    }
    
?>