J2EE Container Managed Security: How to reference the current user

When J2EE container managed security is used the User Principal can be referenced in a number of ways:

Expression Language

       <af:outputText value="#{facesContext.externalContext.userPrincipal.name}"/>

Managed / Backing Bean

       ExternalContext ectx = FacesContext.getCurrentInstance().getExternalContext();
       String userName = ectx.getUserPrincipal().getName();
       System.out.println("Current user: " + userName);

ADF BC Application Module

       String userName = getUserPrincipalName();
       System.out.println("Current user: " + userName);