Android：图像无法从服务器下载

Question

I have uploaded few images on my server which will be downloaded to my android application by passing a url. I have written a php file which displays the image. I pass the URL to my android application like this :

'http://myURL/getImage.php?image=logo.png'.

When I copy paste the URL directly in browser the image is displayed correctly. However the image file is not getting downloaded on my android application. I know that android code is correct because when I am giving any other random image URL the image is downloading correctly. Do I have to give something else in my php file to make the image 'downloadable'.

Image.php

<?php

  echo '<img src="Images/'.$_REQUEST['image'].'"/><br />';

 ?>     

Answer 1

It seems you want the PHP to output the image directly. Instead, your code is generating an HTML with the image on it. Although your browser displays similar results, the underlying content is different.

What you actually need could be this:

<?php

$filepath = 'Images/'.$_REQUEST['image'];
$filename = basename($filepath);
$ctype = 'image/jpeg'; // assuming it is a .jpg file

if (is_file($filepath)) {
    header('Content-Type: '.$ctype);
    header('Content-Length: ' . filesize($filepath));
    header('Content-Disposition: attachment; filename="'.$fileName.'"');
    echo file_get_contents($file);
    exit();
} else {
    header("HTTP/1.0 404 Not Found");
    // you may add some other message here
    exit();
}

This is vulnerable to hazardous $_REQUEST['image'] input. Just filter it somehow. Also you must generate the correct $ctype for the image file.