 try (Workbook workbook = new XSSFWorkbook()) {                 new XlsExporter().exportXls(workbook, grh);                 SimpleDateFormat sdf = new SimpleDateFormat("_dd_MM_yyyy_HH_mm");                 String name = grh.getReportName() + sdf.format(new Date());                 response.setContentType(MediaType.APPLICATION_OCTET_STREAM.getType());                 response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + name +  ".xlsx\"");                 workbook.write(response.getOutputStream());                 response.getOutputStream().flush();             }