if (defaultComponent != null)
  public void upFocusCycle (Component comp)  {    Component focusComp = (comp == null) ? getGlobalFocusOwner () : comp;    Container focusCycleRoot = focusComp.getFocusCycleRootAncestor ();    if (focusCycleRoot instanceof Window)  {        FocusTraversalPolicy policy = focusCycleRoot.getFocusTraversalPolicy ();        Component defaultComponent = policy.getDefaultComponent (focusCycleRoot);        defaultComponent.requestFocusInWindow ();  }    else  {        Container parentFocusCycleRoot = focusCycleRoot.getFocusCycleRootAncestor ();        focusCycleRoot.requestFocusInWindow ();        setGlobalCurrentFocusCycleRoot (parentFocusCycleRoot);      }  }