private String getUserName() {
        AccessControlContext acc = AccessController.getContext();
        Subject subject = Subject.getSubject(acc);
        if (subject != null)  {
            Set<JMXPrincipal> principals = subject.getPrincipals(JMXPrincipal.class);
            JMXPrincipal principal = principals.iterator().next();
            return principal.getName();
        }
        return "JMX";
    }