Java Development Tools

Hi
I am using Jdev 11g and new to adf.
I am trying to work with adf security.
I designed a login.jspx page and loginproxy.jspx accoridng to the following link
http://groundside.com/blog/DuncanMills.php?title=j2ee_security_a_jsf_based_login_form&more=1&c=1&tb=1&pb=1

I have added this code in login.java

     ExternalContext ectx =    FacesContext.getCurrentInstance().getExternalContext();
     HttpServletRequest request =    (HttpServletRequest)ectx.getRequest();
     HttpServletResponse response =    (HttpServletResponse)ectx.getResponse();
     RequestDispatcher dispatcher =   request.getRequestDispatcher("loginnew.jspx");
RequestDispatcher dispatcher =   request.getRequestDispatcher("j_security_check");

    request.setAttribute("j_username", username);
    request.setAttribute("j_password", password);
     dispatcher.forward(request,response);
 

When it tries to execute dispatch statement, it goes in an infinite loop and finally gets me a stack overflow error and also in the cosole it prints series of exceptions like

ActionListenerImpl><processAction> javax.servlet.ServletException: javax.servlet.ServletException: java.lang.NoClassDefFoundError: Could not initialize class oracle.adf.controller.ControllerException
javax.faces.el.EvaluationException: javax.servlet.ServletException: javax.servlet.ServletException: java.lang.NoClassDefFoundError: Could not initialize class oracle.adf.controller.ControllerException

I have to validate the user against database hence i created a login.jspx with a backing bean so that i can access the username and password and validate the credentials against db and redirect user to the appropriate page.
The functionality i want to implement is very simple but i just cant get it to work using adf security.
any help is highly appreciated.

thanks
at