Get current portal role that the application running underneath

My application is available from numerous portal roles. The application needs to know at runtime, which role the user is currently positioned on.

I tried this coding:

<b>NavigationEventsHelperService navHelperService = (NavigationEventsHelperService) PortalRuntime.getRuntimeResources().getService(NavigationEventsHelperService.KEY);

String launchNode = navHelperService.getCurrentLaunchNavNode(request).getName();</b>

but on runtime I got this exception:

<b>java.lang.NoClassDefFoundError: com/sapportals/portal/navigation/NavigationEventsHelperService</b>

I think I should indicate on portalapp.xml on SharingReference, the jar name.

But unfortunately I don't know what is name.

Please your help.

Regards,

Maya.