一个不错的PHP文件下载类

<?
/**
** php文件下载类
**范例：
 $download=new download('php,exe,html',false);
 if(!$download->downloadfile($filename))
 {
 echo $download->geterrormsg();
}
* by www.jb200.com
*/
class download{
var $debug=true;
var $errormsg='';
var $Filter=array();
var $filename='';
var $mineType='text/plain';
var $xlq_filetype=array();

function download($fileFilter='',$isdebug=true)
{
$this->setFilter($fileFilter);
$this->setdebug($isdebug);
$this->setfiletype();
}

function setFilter($fileFilter)
{
if(empty($fileFilter)) return ;
$this->Filter=explode(',',strtolower($fileFilter));
}
function setdebug($debug)
{
$this->debug=$debug;
}

function setfilename($filename)
{
$this->filename=$filename;
}

function downloadfile($filename)
{
$this->setfilename($filename);
if($this->filecheck())
{
$fn = array_pop( explode( '/', strtr( $this->filename, '', '/' ) ) );
header( "Pragma: public" );
header( "Expires: 0" ); // set expiration time
header( "Cache-Component: must-revalidate, post-check=0, pre-check=0" );
header( "Content-type:".$this->mineType );
header( "Content-Length: " . filesize( $this->filename ) );
header( "Content-Disposition: attachment; filename="$fn"" );
header( 'Content-Transfer-Encoding: binary' );
readfile( $this->filename );
return true;
}else
{
return false;
}
}
function geterrormsg()
{
return $this->errormsg;
}

function filecheck()
{
$filename=$this->filename;
if(file_exists($filename))
{
$filetype=strtolower(array_pop(explode('.',$filename)));
if(in_array($filetype,$this->Filter))
{
$this->errormsg.=$filename.'不允许下载！';
if($this->debug) exit($filename.'不允许下载！') ;
return false;
}else
{
if ( function_exists( "mime_content_type" ) )
{
$this->mineType = mime_content_type( $filename );
}
if(empty($this->mineType))
{
if( isset($this->xlq_filetype[$filetype]) ) $this->mineType = $this->xlq_filetype[$filetype];
}
if(!empty($this->mineType))
return true;
else
{
$this->errormsg.='获取'.$filename.'文件类型时候发生错误，或者不存在预定文件类型内';
if($this->debug) exit('获取文件类型出错');
return false;
}
}
}else
{
$this->errormsg.=$filename.'不存在!';
if($this->debug) exit($filename.'不存在!') ;
return false;
}
}

function setfiletype()
{
$this->xlq_filetype['chm']='application/octet-stream';
$this->xlq_filetype['ppt']='application/vnd.ms-powerpoint';
$this->xlq_filetype['xls']='application/vnd.ms-excel';
$this->xlq_filetype['doc']='application/msword';
$this->xlq_filetype['exe']='application/octet-stream';
$this->xlq_filetype['rar']='application/octet-stream';
$this->xlq_filetype['js']="javascript/js";
$this->xlq_filetype['css']="text/css";
$this->xlq_filetype['hqx']="application/mac-binhex40";
$this->xlq_filetype['bin']="application/octet-stream";
$this->xlq_filetype['oda']="application/oda";
$this->xlq_filetype['pdf']="application/pdf";
$this->xlq_filetype['ai']="application/postsrcipt";
$this->xlq_filetype['eps']="application/postsrcipt";
$this->xlq_filetype['es']="application/postsrcipt";
$this->xlq_filetype['rtf']="application/rtf";
$this->xlq_filetype['mif']="application/x-mif";
$this->xlq_filetype['csh']="application/x-csh";
$this->xlq_filetype['dvi']="application/x-dvi";
$this->xlq_filetype['hdf']="application/x-hdf";
$this->xlq_filetype['nc']="application/x-netcdf";
$this->xlq_filetype['cdf']="application/x-netcdf";
$this->xlq_filetype['latex']="application/x-latex";
$this->xlq_filetype['ts']="application/x-troll-ts";
$this->xlq_filetype['src']="application/x-wais-source";
$this->xlq_filetype['zip']="application/zip";
$this->xlq_filetype['bcpio']="application/x-bcpio";
$this->xlq_filetype['cpio']="application/x-cpio";
$this->xlq_filetype['gtar']="application/x-gtar";
$this->xlq_filetype['shar']="application/x-shar";
$this->xlq_filetype['sv4cpio']="application/x-sv4cpio";
$this->xlq_filetype['sv4crc']="application/x-sv4crc";
$this->xlq_filetype['tar']="application/x-tar";
$this->xlq_filetype['ustar']="application/x-ustar";
$this->xlq_filetype['man']="application/x-troff-man";
$this->xlq_filetype['sh']="application/x-sh";
$this->xlq_filetype['tcl']="application/x-tcl";
$this->xlq_filetype['tex']="application/x-tex";
$this->xlq_filetype['texi']="application/x-texinfo";
$this->xlq_filetype['texinfo']="application/x-texinfo";
$this->xlq_filetype['t']="application/x-troff";
$this->xlq_filetype['tr']="application/x-troff";
$this->xlq_filetype['roff']="application/x-troff";
$this->xlq_filetype['shar']="application/x-shar";
$this->xlq_filetype['me']="application/x-troll-me";
$this->xlq_filetype['ts']="application/x-troll-ts";
$this->xlq_filetype['gif']="image/gif";
$this->xlq_filetype['jpeg']="image/pjpeg";
$this->xlq_filetype['jpg']="image/pjpeg";
$this->xlq_filetype['jpe']="image/pjpeg";
$this->xlq_filetype['ras']="image/x-cmu-raster";
$this->xlq_filetype['pbm']="image/x-portable-bitmap";
$this->xlq_filetype['ppm']="image/x-portable-pixmap";
$this->xlq_filetype['xbm']="image/x-xbitmap";
$this->xlq_filetype['xwd']="image/x-xwindowdump";
$this->xlq_filetype['ief']="image/ief";
$this->xlq_filetype['tif']="image/tiff";
$this->xlq_filetype['tiff']="image/tiff";
$this->xlq_filetype['pnm']="image/x-portable-anymap";
$this->xlq_filetype['pgm']="image/x-portable-graymap";
$this->xlq_filetype['rgb']="image/x-rgb";
$this->xlq_filetype['xpm']="image/x-xpixmap";
$this->xlq_filetype['txt']="text/plain";
$this->xlq_filetype['c']="text/plain";
$this->xlq_filetype['cc']="text/plain";
$this->xlq_filetype['h']="text/plain";
$this->xlq_filetype['html']="text/html";
$this->xlq_filetype['htm']="text/html";
$this->xlq_filetype['htl']="text/html";
$this->xlq_filetype['rtx']="text/richtext";
$this->xlq_filetype['etx']="text/x-setext";
$this->xlq_filetype['tsv']="text/tab-separated-values";
$this->xlq_filetype['mpeg']="video/mpeg";
$this->xlq_filetype['mpg']="video/mpeg";
$this->xlq_filetype['mpe']="video/mpeg";
$this->xlq_filetype['avi']="video/x-msvideo";
$this->xlq_filetype['qt']="video/quicktime";
$this->xlq_filetype['mov']="video/quicktime";
$this->xlq_filetype['moov']="video/quicktime";
$this->xlq_filetype['movie']="video/x-sgi-movie";
$this->xlq_filetype['au']="audio/basic";
$this->xlq_filetype['snd']="audio/basic";
$this->xlq_filetype['wav']="audio/x-wav";
$this->xlq_filetype['aif']="audio/x-aiff";
$this->xlq_filetype['aiff']="audio/x-aiff";
$this->xlq_filetype['aifc']="audio/x-aiff";
$this->xlq_filetype['swf']="application/x-shockwave-flash";
}
}
?>