Java EE (Java Enterprise Edition) General Discussion

Hi

I have an isssue I have problems resolving. On a jsp application I have a folder /store/* where users/administrators may upload content (in this case mostly e-learning courses, but it could basically be anything). To be able to control access I want to add a security servlet

    <servlet-mapping>
        <servlet-name>SecurityServlet</servlet-name>
        <url-pattern>/store/*</url-pattern>
    </servlet-mapping>

Looking something like

public class SecurityServlet extends HttpServlet
{
	public void doGet (HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
	{
		if (!user is logged in and have valid access rights)
			res.sendRedirect("someErrorPage.jsp");
		else if (page is a jsp-page)
			res.sendRedirect("someErrorPage.jsp"); //mayor security issue otherwise
		else
			let the user get the requested content
	}
}

The problem is writing the else clause. If I do nothing I only get a blank page in the browser. If I redirect to the url of the request I get an infinite loop. So what are my other options?