Please answer these few doubts

[Rakesh Jhamb]

please just explain me what happens :-
1)after sendError() has been executed and we write to the response.
there is ambiguity in answers given in JWEBPLUS and Study Kit.
2)after forward() has been executed and we write to the response.

3)it is mentioned in Study kit book that setStatus() method does not trigger the error page machinery and just sends the status code directly to the browser, but it is triggering ....
the error page mapped in web.xml for that status code is being displayed.

[Roger Chung-Wee]

If you call setStatus (it doesn't matter if it's an error or non-error status code), the servlet is still responsible for providing the body of the response to the client.
Now, if the status code is, say, 404, and you'd mapped this to an error page in the deployment descriptor, then this probably explains why your error page is being displayed.

[chi Lin]

IllegalStateException will be thrown if continue to write to reponse
after sendError(), sendRedirect(), forward() has being called.
setStatus() will be ignored after the response has been committed.
[ September 23, 2003: Message edited by: chi Lin ]

[Neeraj Singhal]

Hi chi

IllegalStateException will be thrown if continue to write to reponse
after sendError(), sendRedirect(), forward() has being called.

When I tried with Tomcat, it DID NOT throw any IllegalStateException if we continue to write to response after sendError(), sendRedirect(), forward() has being called.

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class test extends HttpServlet
{
public void doGet(HttpServletRequest req, HttpServletResponse res)
{
try
{
res.setContentType("text/html");
PrintWriter out = res.getWriter();

//res.sendRedirect("/test/test.jsp");
//req.getRequestDispatcher("/test.jsp").forward(req,res);
res.sendError(HttpServletResponse.SC_REQUEST_TIMEOUT);

out.println("Hello");
out.flush();
}
catch(Exception e)
{
System.out.println(e);
}
}
}

[chi Lin]

Neeraj,
what I meant to say is :
sendError(), sendRedirect(), forward() will throw IllegalStateException if called after response is committed.
regards