spring mvc を利用して、excelをダウンロード

//印刷ボタン
@RequestMapping(value = "", params = "print", method = RequestMethod.POST)
public String print(HttpServletResponse response,WorkmonthForm workmonthForm, Model model,ModelMap map) throws IOException {

    response.reset();
    response.setContentType("application/vnd.ms-excel;charset=utf-8");
    String sheetNm = "協力会社社員勤休表";
    String fileNm = "2019-04勤务表";
    String fileName = URLEncoder.encode("2019-04勤务表", "UTF-8");


    Workbook workbook = null;
    BufferedInputStream bufferedInputStream = null;
    BufferedOutputStream bufferedOutputStream = null;
    ByteArrayOutputStream os = new ByteArrayOutputStream();

    try {

        String filePath = getClass().getResource("/abc.xls").getPath();
        filePath = filePath.substring(1);
        FileInputStream fileInputStream = new FileInputStream(new File(filePath));

        workbook = WorkbookFactory.create(fileInputStream);
        Sheet sheet = workbook.getSheet(sheetNm);





        List<WorkmonthDto> workmonths = (List<WorkmonthDto>) map.get("workmonths");
        if (workmonths !=null && workmonths.size()>0) {
            for (int i = 0; i < workmonths.size(); i++) {
                WorkmonthDto workmonth = workmonths.get(i);

                Cell cell_start = sheet.getRow(4+i).getCell(2);
                Cell cell_end = sheet.getRow(4+i).getCell(3);


                String start = workmonth.getStart_h()+":"+workmonth.getStart_m();
                String end = workmonth.getEnd_h()+":"+workmonth.getEnd_m();

                if (!":".equals(start)) {
                    double time = DateUtil.convertTime(start);
                    cell_start.setCellValue(time);
                }

                if (!":".equals(end)) {
                    double time = DateUtil.convertTime(end);
                    cell_end.setCellValue(time);
                }

                Cell cell_biko1 = sheet.getRow(4+i).getCell(7);
                cell_biko1.setCellValue(workmonth.getBiko1());

                Cell cell_biko2 = sheet.getRow(4+i).getCell(8);
                cell_biko1.setCellValue(workmonth.getBiko2());


            }
        }



        workbook.write(os);
        byte[] content = os.toByteArray();
        InputStream inputStream = new ByteArrayInputStream(content);

        response.setHeader("Content-Disposition", "attachment;filename=" + new String((fileNm + ".xls").getBytes(), "UTF-8"));
        //response.setHeader("Content-Disposition", "attachment; filename=" + java.net.URLEncoder.encode(fileNm, "UTF-8"));

        ServletOutputStream out = response.getOutputStream();

        bufferedInputStream = new BufferedInputStream(inputStream);
        bufferedOutputStream = new BufferedOutputStream(out);
        byte[] buff = new byte[2048];
        int bytesRead;

        while (-1 != (bytesRead = bufferedInputStream.read(buff, 0, buff.length))) {
            bufferedOutputStream.write(buff, 0, bytesRead);
        }

    } catch (FileNotFoundException e) {
        logger.info(e.getMessage());
    } catch (EncryptedDocumentException e) {
        logger.info(e.getMessage());
    } catch (InvalidFormatException e) {
        logger.info(e.getMessage());
    } catch (IOException e) {
        logger.info(e.getMessage());
    } finally {
        if (bufferedInputStream != null)
            bufferedInputStream.close();
        if (bufferedOutputStream != null)
            bufferedOutputStream.close();
    }

    return null;
}