PHP实现图片批量打包下载功能

上次遇到一个需要打包下载批量图片的问题，找了一下发现这个好方法，记录一下。

首先新建一个zipfile打包类：

<?php
class zipfile {
 var $datasec = array ();
 var $ctrl_dir = array ();
 var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";
 var $old_offset = 0;

function unix2_dostime($unixtime = 0){
   $timearray = ($unixtime == 0) ? getdate () : getdate($unixtime);    
   if ($timearray ['year'] < 1980){
     $timearray ['year'] = 1980;
     $timearray ['mon'] = 1;
     $timearray ['mday'] = 1;
     $timearray ['hours'] = 0;
     $timearray ['minutes'] = 0;
     $timearray ['seconds'] = 0;
   }
   return (($timearray ['year'] - 1980) << 25) | ($timearray ['mon'] << 21) | ($timearray ['mday'] << 16) | ($timearray ['hours'] << 11) | ($timearray ['minutes'] << 5) | ($timearray ['seconds'] >> 1);
 }
 function add_file($data, $name, $time = 0){
   $name = str_replace('\\', '/', $name);

$dtime = dechex($this->unix2_dostime($time));
   $hexdtime = '\x' . $dtime [6] . $dtime [7] . '\x' . $dtime [4] . $dtime [5] . '\x' . $dtime [2] . $dtime [3] . '\x' . $dtime [0] . $dtime [1];
   eval('$hexdtime = "' . $hexdtime . '";');

$fr = "\x50\x4b\x03\x04";
   $fr .= "\x14\x00";
   $fr .= "\x00\x00";
   $fr .= "\x08\x00";
   $fr .= $hexdtime;

$unc_len = strlen($data);
   $crc = crc32($data);
   $zdata = gzcompress($data);
   $zdata = substr(substr($zdata, 0, strlen($zdata)- 4), 2);
   $c_len = strlen($zdata);
   $fr .= pack('V', $crc);
   $fr .= pack('V', $c_len);
   $fr .= pack('V', $unc_len);
   $fr .= pack('v', strlen($name));
   $fr .= pack('v', 0);
   $fr .= $name;

$fr .= $zdata;
   $fr .= pack('V', $crc);
   $fr .= pack('V', $c_len);
   $fr .= pack('V', $unc_len);

$this->datasec [] = $fr;

$cdrec = "\x50\x4b\x01\x02";
   $cdrec .= "\x00\x00";
   $cdrec .= "\x14\x00";
   $cdrec .= "\x00\x00";
   $cdrec .= "\x08\x00";
   $cdrec .= $hexdtime;
   $cdrec .= pack('V', $crc);
   $cdrec .= pack('V', $c_len);
   $cdrec .= pack('V', $unc_len);
   $cdrec .= pack('v', strlen($name));
   $cdrec .= pack('v', 0);
   $cdrec .= pack('v', 0);
   $cdrec .= pack('v', 0);
   $cdrec .= pack('v', 0);
   $cdrec .= pack('V', 32);

$cdrec .= pack('V', $this->old_offset);
   $this->old_offset += strlen($fr);

$cdrec .= $name;

$this->ctrl_dir[] = $cdrec;
 }
 function add_path($path, $l = 0){
   $d = @opendir($path);
   $l = $l > 0 ? $l : strlen($path) + 1;
   while($v = @readdir($d)){
     if($v == '.' || $v == '..'){
       continue;
     }
     $v = $path . '/' . $v;
     if(is_dir($v)){
       $this->add_path($v, $l);
     } else {
       $this->add_file(file_get_contents($v), substr($v, $l));
     }
   }
 }
 function file(){
   $data = implode('', $this->datasec);
   $ctrldir = implode('', $this->ctrl_dir);
   return $data . $ctrldir . $this->eof_ctrl_dir . pack('v', sizeof($this->ctrl_dir)) . pack('v', sizeof($this->ctrl_dir)) . pack('V', strlen($ctrldir)) . pack('V', strlen($data)) . "\x00\x00";
 }

function add_files($files){
   foreach($files as $file){
     if (is_file($file)){
       $data = implode("", file($file));
       $this->add_file($data, $file);
     }
   }
 }
 function output($file){
   $fp = fopen($file, "w");
   fwrite($fp, $this->file ());
   fclose($fp);
 }
}

//下面是实例操作过程：
$dfile = tempnam('/tmp', 'tmp');//产生一个临时文件，用于缓存下载文件
$zip = new zipfile();
//----------------------
$filename = 'image.zip'; //下载的默认文件名

//以下是需要下载的图片数组信息，将需要下载的图片信息转化为类似即可
$image = array(
 array('image_src' => 'pic1.jpg', 'image_name' => '图片1.jpg'),
 array('image_src' => 'pic2.jpg', 'image_name' => 'pic/图片2.jpg'),
);

foreach($image as $v){
 $zip->add_file(file_get_contents($v['image_src']), $v['image_name']);
 // 添加打包的图片，第一个参数是图片内容，第二个参数是压缩包里面的显示的名称, 可包含路径
 // 或是想打包整个目录 用 $zip->add_path($image_path);
}
//----------------------
$zip->output($dfile);

// 下载文件
ob_clean();
header('Pragma: public');
header('Last-Modified:'.gmdate('D, d M Y H:i:s') . 'GMT');
header('Cache-Control:no-store, no-cache, must-revalidate');
header('Cache-Control:pre-check=0, post-check=0, max-age=0');
header('Content-Transfer-Encoding:binary');
header('Content-Encoding:none');
header('Content-type:multipart/form-data');
header('Content-Disposition:attachment; filename="'.$filename.'"'); //设置下载的默认文件名
header('Content-length:'. filesize($dfile));
$fp = fopen($dfile, 'r');
while(connection_status() == 0 && $buf = @fread($fp, 8192)){
 echo $buf;
}
fclose($fp);
@unlink($dfile);
@flush();
@ob_flush();
exit();
?>