IUser problem with com.sapportals.portal.security.usermanagement

I am trying to get the current user so I have written

IUser user = request.getUser();

I have imported com.sap.security.api.*;

The compiler insists I need com.sapportals.portal.security.usermanagement.IUser

I thought that version was deprecated or at least not the preferred method?

It keeps saying my classpath is incomplete. Why can't it use the IUser from the com.sap.security.api?

Any help would be greatly appreciated.

Thanks

Paul