For your reference, the example of this article shares the specific code of java web to export data to Excel file. The specific content is as follows

1. jsp code

< input type=“button” class=“btn btn-info “onclick=“getVerExcel();” value=” export as Excel file ”/ >

2. js code

function getVerExcel() {
  window.location.href = '/pms/jsp/version/getPrdVerListExcel?page='
      + $("#getPage").html() + '&key=' + $("#select").val();
}

3. java code

  /**
   *
   * Purpose : Export the product version list as Excel file
   * @param req
   *       request
   * @param resp
   *       The reply
   * @param page
   *       The current number of pages
   * @param key
   *       Query conditions
   * @return
   */
  @RequestMapping("getPrdVerListExcel")
  public void getExcel(HttpServletRequest req, HttpServletResponse resp, Integer page, String key) {
    //  Setup file mime type
    resp.setContentType("application/vnd.ms-excel");

    //  Get all the data
    List<Version> verList = prdVersionSer.getAllPrdVersion(key);
    //  If there is no data, the user is prompted
    if (verList.size() == 0) {
      req.setAttribute("getFileMsg", " No qualified information! ");
      req.setAttribute("select", key);
      try {
        req.getRequestDispatcher("/jsp/version/ver_list.jsp").forward(req, resp);
      } catch (Exception e) {
        e.printStackTrace();
      }
    } else {
      //  Stores the encoded file name
      String name = "name";
      //  Name of storage file
      String n = "";
      if (key != "") {
        n = verList.get(0).getPrdName() + " Version list of ";
      } else {
        n = " Product version list ";
      }
      try {
        name = URLEncoder.encode(n, "utf-8");
      } catch (UnsupportedEncodingException e1) {
        e1.printStackTrace();
      }
      resp.setHeader("content-disposition",
          "attachment;filename=" + name + ".xls;filename*=utf-8''" + name + ".xls");

      System.out.println("key:" + key);

      //  from session Remove the saveExcelMsg attribute
      req.getSession().removeAttribute("saveExcelMsg");
      //  define 1 An output stream
      ServletOutputStream sos = null;

      //  create 1 A workbook
      HSSFWorkbook wb = new HSSFWorkbook();
      //  create 1 A worksheet
      HSSFSheet sheet = null;
      if (key != "") {
        sheet = wb.createSheet(verList.get(0).getPrdName() + " Version information ");
      } else {
        sheet = wb.createSheet(" Product version information ");
      }
      //  Returns a data format object
      //  Gets the number of the corresponding date format from the format object, and if the format does not exist, the method generates a new number for it
      HSSFDataFormat format = wb.createDataFormat();
      short dfNum = format.getFormat("yyyy-mm-dd");
      //  Creating a style object
      CellStyle style = wb.createCellStyle();
      //  Format the data
      style.setDataFormat(dfNum);
      //  Create the first 1 Row (table header)
      HSSFRow row = sheet.createRow(0);
      HSSFCell cell = row.createCell(0, HSSFCell.CELL_TYPE_STRING);
      if (key != "") {
        cell.setCellValue(verList.get(0).getPrdName() + " Product version list ");
      } else {
        cell.setCellValue(" Product version list ");
      }

      //  Create the first 2 Line (header)
      row = sheet.createRow(1);
      cell = row.createCell(0, HSSFCell.CELL_TYPE_STRING);
      cell.setCellValue(" The serial number ");

      cell = row.createCell(1, HSSFCell.CELL_TYPE_STRING);
      cell.setCellValue(" The product name ");

      cell = row.createCell(2, HSSFCell.CELL_TYPE_STRING);
      cell.setCellValue(" The version number ");

      cell = row.createCell(3, HSSFCell.CELL_TYPE_STRING);
      cell.setCellValue(" The release date ");

      cell = row.createCell(4, HSSFCell.CELL_TYPE_STRING);
      cell.setCellValue(" Version type ");

      cell = row.createCell(5, HSSFCell.CELL_TYPE_STRING);
      cell.setCellValue(" Version described ");

      int num = 1;
      //  Traverse the output verList , and store it Excel In the
      for (int i = 0; i < verList.size(); i++) {
        row = sheet.createRow(i + 2);
        //  Write the serial number
        cell = row.createCell(0, HSSFCell.CELL_TYPE_NUMERIC);
        cell.setCellValue(num);
        num++;
        //  Write the product name
        cell = row.createCell(1, HSSFCell.CELL_TYPE_STRING);
        cell.setCellValue(verList.get(i).getPrdName());
        //  Write version number
        cell = row.createCell(2, HSSFCell.CELL_TYPE_STRING);
        cell.setCellValue(verList.get(i).getVerNo());

        //  Write the release date ( Date format does the processing )
        cell = row.createCell(3, HSSFCell.CELL_TYPE_STRING);
        //  Apply the style to the cell
        cell.setCellStyle(style);
        cell.setCellValue(verList.get(i).getVerDate());

        //  Write version type
        cell = row.createCell(4, HSSFCell.CELL_TYPE_STRING);
        cell.setCellValue(verList.get(i).getVerType());

        //  Write version description
        cell = row.createCell(5, HSSFCell.CELL_TYPE_STRING);
        cell.setCellValue(verList.get(i).getVerDesc());
      }
      try {
        //  Save to a file
        sos = resp.getOutputStream();
        wb.write(sos);
      } catch (Exception e) {
        e.printStackTrace();
      } finally {
        if (sos != null) {
          try {
            sos.close();
          } catch (IOException e) {
            e.printStackTrace();
          }
        }
      }
    }
  }