JavaFX怎么关闭弹出的窗口？

Question

在MainStageController控制器中点击按钮会打开一个新窗口，怎么在第二次点击时判断如果弹出过这个窗口了，就不弹了

 @FXML
  private void handleSubmitButtonAction(ActionEvent event) {
    actionTarget.setText("登录中...");

    /**
     * 得到对应视图的stage
     */
    Stage stage = (Stage) rootGridPane.getScene().getWindow();
    stage.close();

    // 创建新的stage
    Stage secondStage = new Stage();
    final JmetroStageView view = new JmetroStageView();
    ApplicationContext context = SpringContextUtil.getApplicationContext();
    view.setApplicationContext(context);
    secondStage.setScene(new Scene(view.getView()));
    secondStage.show();
  }