servlets - 将 poi 工作簿写入输出流会产生奇怪的值

Question

我的目标是创建一个 Excel 文件供用户通过 apache poi 下载。

我的 servlet 中有此代码:

protected void doGet(HttpServletRequest request, 
              HttpServletResponse response) throws ServletException, IOException 
      {

            // create a workbook , worksheet
            Workbook wb = new HSSFWorkbook();
            Sheet sheet = wb.createSheet("MySheet");
            CreationHelper createHelper = wb.getCreationHelper();

            // Create a row and put some cells in it. Rows are 0 based.
            Row row = sheet.createRow((short)0);
            Cell cell = row.createCell(0);
            cell.setCellValue(1);
            row.createCell(1).setCellValue(1.2);
            row.createCell(2).setCellValue( createHelper.createRichTextString("This is a string") );
            row.createCell(3).setCellValue(true);

            //write workbook to outputstream
            ServletOutputStream out = response.getOutputStream();
            wb.write(out);
            out.flush();
            out.close();

            //offer the user the option of opening or downloading the resulting Excel file
            response.setContentType("application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment; filename=MyExcel.xls");

问题是我得到了这些奇怪的值:

`…MySheetŒ®üÿ » ÌÁ w dü©ñÒMbP?*+‚€%ÿÁƒ„¡"d,,à?à?

有什么建议？

Answer 1

发现出了什么问题。 HttpServletResponse 必须在其他任何事情之前先设置

//offer the user the option of opening or downloading the resulting Excel file
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-Disposition", "attachment; filename=MyExcel.xls");