Download generated zip from servlet

Question

I know this is a very basic question but there are so many implementations out there and I can't get them to work.

So in my project if the user clicks a button, I'm generating a zip file on a servlet (which is called through an AJAX POST ). Naturally, I want that file to get downloaded to the user.

Here's my code for the request:

<button type="button" class="btn btn-info btn-lg" onclick="getZip();">
    <span class="glyphicon glyphicon-download"></span> Download clusters (.zip)
</button>

Here's the AJAX for the POST :

function getzip() {
    $.ajax({
        url:'GetZipServlet',
        type:'GET',
    });
}

And this is my code for the download:

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        System.out.println("Downloading clusters.zip");

        /* Generate the directory on the server, then zip it. */
        ClinicoGenomic.getInstance().clustersToFiles();
        ClinicoGenomic.getInstance().zipClusters();
        System.out.println("Done generating the .zip");

        String parent_dir = System.getProperty("catalina.base");
        String filename = "clusters.zip";



        response.setContentType("application/zip");
        response.setHeader("Content-Disposition", "attachment;filename=\"" + filename);
        ZipOutputStream zipStream = new ZipOutputStream( response.getOutputStream() );

        ZipInputStream fi = new ZipInputStream(new FileInputStream(parent_dir + "/" + filename));
        int i;
        while ((i = fi.read())!=-1)
            zipStream.write(i);

        zipStream.close();
        fi.close();
        System.out.println(".zip file downloaded at client successfully");
    }

I get the correct messages in my console, up to the .zip file downloaded at client successfully . But the download doesn't start. what could be wrong here???

Answer 1

if you are correctly sending the response you should just simply handle it after your ajax call, like this:

$.ajax({
  url:'GetZipServlet',
  type:'GET',
  success: function (response) {
     //handle the response here
  }
});