java web 下載本地文件並彈出下載框

window.open("/dept/download")

@RequestMapping(value = "/download", method = RequestMethod.GET)
    public void downstudents(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String filename = request.getSession().getServletContext().getRealPath("/static/email/");
        String filenameZip = filename + "\\dept.xls";

        try {
            response.setContentType("application/x-execl");
            response.setHeader("Content-Disposition",
                    "attachment;filename=" + new String(("dept.xls").getBytes(), "UTF-8"));
            // 讀取文件
            InputStream in = new FileInputStream(filenameZip);
            ServletOutputStream outputStream = response.getOutputStream();
            // 寫文件
            int b;
            while ((b = in.read()) != -1) {
                outputStream.write(b);
            }

            in.close();
            outputStream.close();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }