JAVA POI 操作excel问题，向AA列插入值时，没有效果

java poi 在向excel 列名为AA 插入值时，插入不进去，也不报任何错

try (ServletOutputStream outputStream = response.getOutputStream()) {

        String path = Thread.currentThread().getContextClassLoader().getResource("").getPath();
        FileInputStream fileInputStream = new FileInputStream(path+"/export_temp/XXXX.xlsx");
        XSSFWorkbook workbook = new XSSFWorkbook(fileInputStream);
        Sheet sheet = workbook.getSheetAt(0);
        for (int i = 4; i < 10; i++) {
            Row row = sheet.createRow(i);
            Cell cell = row.createCell(0);
            cell.setCellValue("XXX");
            Cell cell1 = row.createCell(1);
            Cell cell2 = row.createCell(2);
            Cell cell3 = row.createCell(3);
            Cell cell4 = row.createCell(4);
            Cell cell5 = row.createCell(5);
            cell5.setCellValue("XXXX");
        }
        SimpleDateFormat sdf = new SimpleDateFormat("_yyyyMMdd");
        String fileName = "XXXX_" + sdf.format(new Date()) + ".xlsx";
        String encode = URLEncoder.encode(fileName, "UTF-8");
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setHeader("Content-Disposition", "attachment;filename=" + encode);
        workbook.write(outputStream);
    } catch (IOException e) {
        e.printStackTrace();
    }