title: how can i get the Principal in interceptor using spring mvc?
body: <p>I write Web project in spring MVC 3.1 and i implement Interceptor class by extends HandlerInterceptorAdapter and i need to find a way get the Principal.
  I try request.getUserPrincipal() and it return null,
  I try request.getRemoteUser() and it return null.
  I using Oauth 2 and basic Authentication.
  Thanks.</p>