Classcast Exception when VaadinServletRequest is cast to AppsRequestWrapper

Hello 

I am developing a vaadin application and Integrating it with Oracle APPS. so when the application
is launched from Oracle Apps the vaadin servlet class recieves the request and validate the session 
and then forward it to the UI.

To get the apps session we need to do something like this in the servlet class

AppsRequestWrapper wrappedRequest = (AppsRequestWrapper)request;
Session session = wrappedRequest.getAppsSession(true);

But upon deploying the application I get the following error on Tomcat server

java.lang.ClassCastException: org.apache.catalina.connector.RequestFacade cannot be 
cast to oracle.apps.fnd.ext.common.AppsRequestWrapper.

and on weblogic i get

java.lang.ClassCastException: weblogic.servlet.internal.ServletRequestImpl cannot be 
cast to oracle.apps.fnd.ext.common.AppsRequestWrapper

If I create a VaadinServletRequst  using createVaadinRequest(request) and then cast it to AppsRequestWrapper
i get the following error

java.lang.ClassCastException: com.vaadin.server.VaadinServletRequest cannot be cast to oracle.apps.fnd.ext.common.AppsRequestWrapper

I dont have any server specific jars in WEB-INF/lib of application. Is there a way to get around this problem

Thanks in advance