flush() in rd.include vs rd.forward()

[luke brown]

i have the following code snippet in my web app:

	if(request.getParameter("user").equals("luke")||session == null && !(uri.endsWith("html") || uri.endsWith("LoginServlet"))){
			System.out.println("<<<----------denied------------->>>>");
			pw.println("zzzzzzzzzz");
			this.context.log("Unauthorized access request");
			pw.flush();
			try {
				Thread.sleep(5000);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			//res.sendRedirect("login.html");
			req.getRequestDispatcher("login.html").include(request,response);
		}

When i am using flush before Forward(), its throwing illegalstateexception (since the response is sent the moment we call flush and later we are trying to resend the response using forward) but the code works fine even after i provided flush before the rd.include(). Why doesnt it throw the exception here?

Regards
Luke

[Frits Walraven]

The include method of the RequestDispatcher interface does not throw an IllegalStateException.

Just check the Servlet 3.0 specs chapter 9.3 (The Include Method) and 9.4 (The Forward Method)