php文件下载后无法打开的处理方案及代码

ob_clean();
flush();

if(isset($_GET['action'])&&$_GET['action'] == 'download')
{
if($_GET['file'])
{
$fileinfo = pathinfo($_GET['file']);
header('Content-type: application/x-'.$fileinfo['extension']);
header('Content-Disposition: attachment; filename=favicon.ico');
ob_clean();
    flush();
readfile($_GET['file']);
exit();
}
}

if (file_exists(CACHE_PATH . $file_name)){

            //$this->logger->error('file realpath:'.realpath(CACHE_PATH . $file_name));

      header( 'Pragma: public' );

      header( 'Expires: 0' );

      header( 'Content-Encoding: none' );

      header( 'Cache-Control: must-revalidate, post-check=0, pre-check=0' );

      header( 'Cache-Control: public' );

   header( 'Content-Type: application/vnd.ms-excel');

      header( 'Content-Description: File Transfer' );

      header( 'Content-Disposition: attachment; filename=' . $file_name );

      header( 'Content-Transfer-Encoding: binary' );

      header( 'Content-Length: ' . filesize ( CACHE_PATH . $file_name ) );

      readfile ( CACHE_PATH . $file_name );

  } else {

   $this->logger->error('export model :'.$id.' 错误：未生产文件');

      echo '';

  }