java code for ForwardException - show forwarding an exception to an error page

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

/*
* ForwardException - show forwarding an exception to an error page.
*
* @author Ian Darwin
* @version $Id: ForwardException.java,v 1.2 2002/03/13 21:50:30 ian Exp $
*/
public class ForwardException extends HttpServlet
{
/** Called in response to a GET request (data encoded in the URL) */
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

ServletContext application = getServletContext();

// BOILERPLATE beginning
response.setContentType("text/html");
PrintWriter out = response.getWriter();

try {
// to do: logic code and main HTML goes here.

// simulate an error condition happening at run time.
if (this instanceof Servlet)
throw new RuntimeException("Test exception");

out.println(" "\"-//W3C//DTD XHTML 1.0 Transitional//EN\"\n" +
"\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"\n" +
">");
out.println("");
out.println("");
out.println("");

// BOILERPLATE ending
out.println("");
out.println("");
out.close();

} catch (Exception exc) {

// dispatch to JSP to display the error.
RequestDispatcher rd = application.getRequestDispatcher("/oops.jsp");
request.setAttribute("javax.servlet.jsp.jspException", exc);
rd.forward(request, response);
}
}
}