You are viewing a plain text version of this content. The canonical link for it is here.

Posted to users@tomcat.apache.org by Scott Hamilton <ha...@grunj.cat.org.au> on 2000/11/30 05:29:37 UTC

RE[2]: tomcat 3.2b8 and response.flushBuffer()

>Craig,
>
>I was wrong, it's not a problem with tomcat, it's
>a different behavior of the browsers: with navigator
>(and opera) flushBuffer works as expected, with ie the first
>time the page shows up only when completely loaded, but when
>reloading the page shows up before as it should, go guess..
> 

   Yeah Internet Exploder has a rather aggressive Caching
   algorithm (if it can be called that??) and because it
   refuses to use the MIME type specified in the Content-type
   header, it can cache things that one doesn't really want
   cache... I wrote a Data-level security module for Apache
   and one of the things we had to add in the HTTP headers
   just for IE is

   Cache-control: no-cache

   There is another one, that has escaped my head for the moment
   but both needed to be there for the brain-dead to truly not
   cache something that just shouldn't be cached.....


   Scott, Esq.

Re: tomcat 3.2b8 and response.flushBuffer()

Posted by Mauro Bertapelle <ma...@jmatica.com>.

Scott,

I've finally got it.
The problem with Internet Explorer is that, no matter
how many flavors of no-cache, cache-no, no-cache-thanks, etc..
you put in your header, it'll not output anything until it
has read at least 256 characters:

public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {

  response.setContentType("text/html");
  response.setIntHeader("Expires", -1);
  response.addHeader("Cache-Control", "no-cache");
  response.addHeader("pragma", "no-cache");
  PrintWriter out = response.getWriter();
  out.println("<html>");                     // 7
  out.println("<head><title>Title</title>"); // 34
  out.println("</head><body>");              // 48
  out.println("<!-----------------------------------------------------------------------------"); // 128
  out.println("-------------------------------------------------------------------------------"); // 208
  // out.println("---------------------------------> phase 1<br>"); // 255, doesn't display till end of page
  out.println("----------------------------------> phase 1<br>"); // 256, start display immediately

  response.flushBuffer();

  try {
    Thread.sleep(5000);
  } catch (Exception e) {
  };
  out.println("phase 2");
  out.println("</body>");
  out.println("</html>");
  out.close();
}

Regards,

Mauro Bertapelle
JMatica Srl
mauro.bertapelle@jmatica.com
--