Pdf caching issue

Question

Hi,
I have a serlvet which calls a series of classes which generate a pdf on the fly. Once created on the server, the servlet then calls response.sendRedirect("path to .pdf");. This all works fine. My problem is when I change the data which appears in the pdf and generate it again through the same servlet (with the same filename). The second time the pdf is opened in the clients browser, it contains the first/original pdf data, until I refresh the browser and it generates it again with the updated data. This, I'm guessing, is because of a caching issue. However, in the calling servlet, I set both Cache-Control and Pragma to "no-cache". Is there something I'm missing? Thanks
   public void doGet (HttpServletRequest req, HttpServletResponse resp)
   throws ServletException, IOException
      resp.setHeader("Cache-Control", "no-cache");
      resp.setHeader("Pragma", "no-cache");
      ...//generate pdf on server
      resp.sendRedirect("path to file");
   }

Answer 1

I don't know if this applies to pdf's but for HTML I have scrounged the Internet and come up with this:
    public static void disableCaching(HttpServletResponse response)
        response.addDateHeader("Expires", 791589600000L); // Wed Feb 01 00:00:00 EET 1995
        response.addHeader("Cache-Control", "no-store,no-cache,must-revalidate,post-check=0,pre-check=0");
        response.addHeader("Pragma", "no-cache");
    }Most of the horror in that is due to Internet Exploder. Different versions of IE require different magic spells. Googling for "no-store no-cache" etc finds more on the subject.