Question

I am trying to download a file from a webserver and save it under the original filename the server is sending with the file. Downloading works very well, but I am not able to get the real filename.

For real example I am trying to download this file (Foxit PDF Reader).

If I am using this link in a browser like Chrome the browser downloads the file with a exact name including version etc. Where do I get this name from? I tried reading the header informations and was searching for Content-Disposition but the server doesn’t send this information. Where do I get the exact filename from?

I tried something like this:

try {            
  URL webfile = new URL("http://www.foxitsoftware.com/downloads/latest.php?product=Foxit-Reader");
  URLConnection con = webfile.openConnection();
  Map map = con.getHeaderFields();
  Set set = map.entrySet();
  Iterator iterator = set.iterator();
  while (iterator.hasNext()) {
      System.out.println(iterator.next());
  }
} catch (IOException ex) {
  System.out.println("Error: "+ex.getMessage());
}

As you can see in the output there is no Content-Disposition:

null=[HTTP/1.1 200 OK]
ETag=["244005-f36d40-4d003f3868000"]
Date=[Sat, 08 Dec 2012 12:29:02 GMT]
Content-Length=[15953216]
Last-Modified=[Tue, 04 Dec 2012 10:01:36 GMT]
Content-Type=[application/x-msdos-program]
Connection=[close]
Accept-Ranges=[bytes]
Server=[Apache/2.2.16 (Debian)]

So how can I retrieve the exact filename? The link in a browser downloads a file with the name FoxitReader544.11281_enu_Setup.exe.

Any ideas?!

Answer 1

GET /downloads/latest.php?product=Foxit-Reader HTTP/1.1

gives a response of HTTP/1.1 302 Found

and sets the response header

Location: http://cdn04.foxitsoftware.com/pub/foxit/reader/desktop/win/5.x/5.4/enu/FoxitReader544.11281_enu_Setup.exe

and finally, you issue,

GET /pub/foxit/reader/desktop/win/5.x/5.4/enu/FoxitReader544.11281_enu_Setup.exe HTTP/1.1

That is where the filename seems to be coming from.
So, if the redirection is happening transparently, you could still probably get the filename from the request parameter.