下载的zip文件已损坏

Question

I'm trying to let user download a zip file from server using this code : SERVER:

 @RequestMapping(value = "/get-shape-file", method = RequestMethod.GET)
public void getFile( HttpServletRequest request, HttpServletResponse response) throws IOException {
    BufferedReader rd = new BufferedReader (new FileReader("/shape/lastlyExportedFileName"));    
    String fileName = rd.readLine().trim();
    rd.close();
    try {            
        OutputStream myOut = null;
        FileInputStream fileInputStream = null;
        File downzip = new File("/shape/" + fileName);

        response.setContentType("TEXT/HTML");
        response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
        response.setContentLength((int) downzip.length());
        System.out.println("length  " + (int) downzip.length());
        //READ DATA FROM FILE

        byte[] dataRead = new byte[(int) downzip.length()];
        fileInputStream = new FileInputStream(downzip);
        fileInputStream.read(dataRead, 0, (int) downzip.length());
        //WRITE DATA TO OUTFILE
        myOut = response.getOutputStream();
        myOut.write(dataRead);

        if (fileInputStream != null) {
            fileInputStream.close();
        }

      } catch (IOException ex) {
        logger.error("Error writing file to output stream. Filename was '" + fileName + "'");
        throw new RuntimeException("IOError writing file to output stream");
      }
}

Client:

 $.ajax({
    url: 'url-to-the-method/get-shape-file',
    type: 'GET',
    success: function(shape) {
        console.log(shape);
        var a = document.createElement('a');
        a.href = 'data:attachment/zip,' + shape;
        a.target = '_blank';
        a.download = 'exported-shape-file.zip';
        document.body.appendChild(a);
        a.click();
    },
    error: function(data) {
        Message.error("Could not download shapefile");
    }
});       

But downloaded file is corrupted. Size is larger than it should be, also when trying to open the file in archive manager this message is shown: zipinfo: cannot find zipfile directory in one of /home/tengiz/Downloads/exported-shape-file (1).zip or /home/tengiz/Downloads/exported-shape-file (1).zip.zip, and cannot find /home/tengiz/Downloads/exported-shape-file (1).zip.ZIP, period.

Answer 1

I solved the problem, turns out that problem was on client side not on server side. On client-side I was trying to attach the response to href but as response contained byte code it was loosing some important characters. What you need to do is just create a tag with link to the controller method, so you don't need any ajax requests like this:

        var a = document.createElement('a');
        a.href = '/url-to/get-shape-file';
        document.body.appendChild(a);
        a.click();