Java另存为对话框，用于在路径中保存文件

Question

我有一个表单，它接受PDF文件并提交给servlet。在阅读PDF的内容后，我正在使用Apache POI在servlet中创建一个xls文件，我想将其保存到本地光盘。

            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = workbook.createSheet("Data");

            ArrayList<String> keys = new ArrayList<String>(excelData.keySet());

            int counter = 0;

            for(int i=keys.size()-1; i>=0;i--){

              String key = keys.get(i);
              String value = excelData.get(key);

              Row row = sheet.createRow(counter++);

              Cell cell = row.createCell(0);
              cell.setCellValue(key);

              Cell cell1 = row.createCell(1);
              cell1.setCellValue(value);  
            }

//工作簿是我目前正在保存的xls数据，

                FileOutputStream out = new FileOutputStream(new File("C:\\Users\\user\\Desktop\\new.xls"));
                workbook.write(out);
                out.close();

                //return back to same page.
                response.sendRedirect(request.getHeader("Referer"));

我想提供一个C:\\Users\\user\\Desktop\\new.xls选项来选择用户想要保存的文件的路径和名称，而不是直接将文件保存到save as。有点像：

如何将此文件发送回客户端浏览器并显示另存为选项。

Answer 1

                //read file back after saving to some temp path.
                File pdfFile = new File("D:\\temp\\"+ fileName +".xls");

                response.setContentType("application/vnd.ms-excel");
                response.setHeader("Content-Disposition", "attachment; filename="+fileName+".xls");

                FileInputStream fileInputStream = new FileInputStream(pdfFile);
                OutputStream responseOutputStream = response.getOutputStream();
                int bytes;
                while ((bytes = fileInputStream.read()) != -1) {
                    responseOutputStream.write(bytes);
                }

                fileInputStream.close();