Javascript在边界中心调整ImageView大小

我有一个图像视图在一个边界的中心.左右两个按钮.BorderPendix在一个分割窗格中.我将ImageView的大小绑定到Borderies，如下所示:

imageView.fitHeightProperty().bind(borderPane.heightProperty());
imageView.fitWidthProperty().bind(borderPane.widthProperty());
imageView.setManaged(false);

它rezise，但图像不是在中心时，setManage是假的.如果我go 掉这些线条，图像在中间是很好的. 这里有一个mwe:

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) {
        try {

            SplitPane root = new SplitPane();
            BorderPane borderPane = new BorderPane();
            ImageView imageView = new ImageView();
            VBox placeHolder = new VBox();
            
            imageView.fitHeightProperty().bind(borderPane.heightProperty());
            imageView.fitWidthProperty().bind(borderPane.widthProperty());
            imageView.setManaged(false);
            
            borderPane.setCenter(imageView);
            imageView.setImage(new Image("pathToImage"));
            root.getItems().addAll(borderPane,placeHolder);
            Scene scene = new Scene(root,700,700);          
            primaryStage.setScene(scene);
            
            primaryStage.show();
        } catch(Exception e) {
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

enter image description here

我正在寻找一种方法来存档两者.我试着用Hbox作为按钮和imageview的容器，但这也禁用了大小调整.