Question about RequestProcessor

[pajarokillo]

Hi, i want from my RequestProcessor forward to ActionClass, for example

protected boolean processPreprocess(HttpServletRequest request,HttpServletResponse response){

doForward("/prueba.do",request,response);
return super.processPreprocess(request,response);
}

and in my action class i have the next code in the execute method

public ActionForward execute(ActionMapping mapping,ActionForm form,
HttpServletRequest request,HttpServletResponse response) throws Exception{

//do something

return (mapping.findForward(IConstants.SESSION_EXPIRADA));
}

but it cause the next error
java.lang.IllegalStateException: Cannot forward after response has been commited

Can i do a forward from my RequestProcessor class to Action class and then forward to JSP page?, and it's possible, how can i do it?