How to force download file with Spring controller?

i have a string controller to download a xml file but the download window is open everytime..

this is the code of my controller :

    @RequestMapping(value = "/export", method = RequestMethod.POST)
@ResponseBody
public void export(HttpServletRequest request, HttpServletResponse response) throws JsonGenerationException,
        JsonMappingException, IOException, DatatypeConfigurationException {
    byte[] bytes  = service.exportXML(getUsername());
    String xmlFileName = "filename.xml";
     response.setContentType("application/force-download");
     response.setHeader("Content-Length", String.valueOf(bytes.length));
     response.setHeader("Content-Disposition", "attachment; filename="+xmlFileName);

     response.getOutputStream().write(bytes);
}

What i can do to browser never open download window and save the file immediately?