public static String getAuthenticatedName() {
    return getAuthenticatedName(null);
  }
Gets the name of the logged in user.  Thread-safe due to use of thread-local.

@return the name of the logged in user, or <code>null</code> if none set.
ambari-server/src/main/java/org/apache/ambari/server/security/authorization/AuthorizationHelper.java