Java下载Excel文件

    public String downTemplate(HttpServletRequest request, HttpServletResponse response) throws IOException {
        File f = ResourceUtils.getFile("classpath:template/导出成绩.xls");
        try {
            response.setCharacterEncoding("UTF-8");
            String fileName = new String("导出成绩.xls".getBytes("UTF-8"),
                    "ISO8859-1");
            fileName = fileName.replaceAll("\\+", "%20");
            response.setHeader("Cache-control", "private");
            response.setHeader("Cache-Control", "maxage=3600");
            response.setHeader("Pragma", "public");
            response.setContentType("application/vnd.ms-excel");
            response.setContentType("application/octet-stream;charset=UTF-8;");
            response.setHeader("Accept-Ranges", "bytes");
            response.setHeader("Content-disposition", "attachment; filename=\"" + fileName + "\"");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        ServletOutputStream out = response.getOutputStream();
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            bis = new BufferedInputStream(new FileInputStream(f));
            bos = new BufferedOutputStream(out);
            byte[] buff = new byte[2048];
            int bytesRead;
            while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                bos.write(buff, 0, bytesRead);
            }
        } catch (final IOException e) {
            throw e;
        } finally {
            if (bis != null)
                bis.close();
            if (bos != null)
                bos.close();
        }
        return null;
    }