spring mvc export excel failed sometimes and data displays garblend on the page

There is a data report as the following in my project, I want to export it as excel: But the wierd thing is that sometimes it exports successfully and sometimes failed. I have tried many times and it turns out that when the excel sheet is over 17 lines, it will lead to this:

1. the page redirects to a new page with garblend data.
2. the post request has been changed to get request.

It's sure that the excel is successfully created even if it exports failed, because I have written it to disk and checked the file. The following is the controller, what goes wrong with me?

   @RequestMapping("/download")
    public void download(HttpServletRequest request, HttpServletResponse response, ReportCondition condition){
        try {
            List<HashMap<String, String>> mapList = reportFormService.find(condition);
            if(mapList == null || mapList.size() == 0){
                logger.info("No reports...");
            }

            Map<String, Date> dateMap = DateConditionUtil.getStartEndDate1(condition.getStartDate(), condition.getEndDate());
            String startDate = DateFormatUtils.format(dateMap.get("startDate"), "yyyyMMdd");
            String endDate = DateFormatUtils.format(dateMap.get("endDate"), "yyyyMMdd");
            String[] titleArr = new String[]{"序号","日期","应用系统","短信服务商","请求发送总数","请求成功数量","实际短信条数","实际成功条数","费用","失败数量","成功率"};
            String[] fieldArr = new String[]{"ID","RECORDDATE","APPNAME","PROVIDERNAME","SENDCOUNT","SUCCESSCOUNT","SENDSUM","SUCCESSSUM","TOTALFEE","FAILURECOUNT","SUCCESSRATE"};

            ByteArrayOutputStream os = new ByteArrayOutputStream();
            WorkBookUtil.createExcel(titleArr, fieldArr, mapList, os);

            try(BufferedInputStream bis = new BufferedInputStream(new ByteArrayInputStream(os.toByteArray()));
                BufferedOutputStream bos = new BufferedOutputStream(response.getOutputStream())){
                byte[] buff = new byte[1024];
                int bytes;
                while (-1 != (bytes = bis.read(buff, 0, buff.length))) {
                    bos.write(buff, 0, bytes);
                }
                bos.flush();
            }catch (Exception e){
                logger.error(e);
            }

            response.setCharacterEncoding("utf-8");
            response.setHeader("content-disposition", "attachment;filename=" + String.format("%s-%s.xls", startDate, endDate));
            response.setContentType("application/vnd.ms-excel;charset=utf-8");

        } catch (IOException e){
            logger.error("Export failed", e);
        }
    }