Question

I have a page in JSP that list some file that could be downloaded by a user.
Thoses files are not on the local server, they are on a remote file server.

When the user click to download a file, the webserver connect via TCP to the file server. The web server download the file and create a HTTP response for the client.

Here is my code:

<%@page language="java"%>
<%@page import="sun.misc.Request"%>
<%@page import="listing.ClientTCPStockage"%>
<%@page import="java.net.InetAddress"%>

<%
out.clearBuffer();

String nomFichier = request.getParameter("fichier");
String adresseStockage = request.getParameter("adresseStockage");

ClientTCPStockage clientStockage = new ClientTCPStockage(InetAddress.getByName(adresseStockage), 2004);
byte donneeFichier[] = clientStockage.getDonneesFichier(nomFichier);

response.setHeader("Content-Disposition", "attachment;filename=\"" + nomFichier + "\"");
response.setHeader("Content-Type", "application/octet-stream;");
response.setHeader("Accept-Ranges", "bytes");
response.setHeader("Content-Length", String.valueOf(donneeFichier.length));

for(int i = 0; i < donneeFichier.length; i++){
    out.write(donneeFichier[i]);
}
%>

This is working perfectly fine for text-based file, like .csv or normal .txt
but It doesnt work for other type like .mp3 or .jpeg.. the files end up corrupt.

I think there is a problem with my encoding but I can’t find where..

Here is the HTTP Header response:

HTTP/1.x 200 OK
Server: Apache-Coyote/1.1
Content-Disposition: attachment;filename="test.mp3"
Accept-Ranges: bytes
Content-Type: application/octet-stream;
Content-Length: 5387668
Date: Sun, 20 Dec 2009 18:52:18 GMT

Thanks.

Answer 1

If forced to use jsp (and not a servlet), you may take a look at this how-to

It uses the ServletOutputStream, which is more appropriate for binary content, rather than a JspWriter.

Also note the settings for trimming the whitespaces.