我正在使用itext-pdf来生成我的pdf，它正确地保存在服务器中，但应该在客户端下载（保存）。我调用方法从jsp页面生成pdf。这是我的密码：

calling:
  Document b = new JavaPdfHelloWorld().Generate_pdf(con.getCon(), file_no, pdt);
 definition:
         public class JavaPdfHelloWorld {
           public Document Generate_pdf(Connection con, String file_no, PensionDataDao pdt) throws IOException, IOException {
    Document document = new Document();
    String home = System.getProperty("user.home");
    System.out.println(home);
    File file = new File(home + "/Downloads/dcrg-diff/" + name_of_pensioner + " " + space + " "
                    + updated_file_no + ".pdf");
   FileOutputStream pdfFileout = new FileOutputStream(file);
            PdfWriter.getInstance(document, pdfFileout);
    document.open();
    document.add(new Paragraph("CALCULATION SHEET AS PER GRATUITY ACT 1972",
                    FontFactory.getFont(FontFactory.COURIER_BOLD, 18, Font.BOLD, BaseColor.RED)));
            document.close();
            writer.close();
   return document;