Java Swing - 如何动态更改JTree的Node图像

import java.awt.BorderLayout;
import java.awt.Component;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellRenderer;

class CustomTreeCellRenderer extends DefaultTreeCellRenderer {
  ImageIcon rendererIcon;

  public void setRendererIcon(ImageIcon myIcon) {
    this.rendererIcon = myIcon;
  };

  public Component getTreeCellRendererComponent(JTree tree, Object value,
      boolean selected, boolean expanded, boolean leaf, int row,
      boolean hasFocus) {

    super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf,
        row, hasFocus);

    JLabel label = (JLabel) this;

    label.setIcon(rendererIcon);

    return this;
  }
}

public class Main {
  public static void main(String[] args) {
    ImageIcon iconWhite = new ImageIcon("white.jpg");
    ImageIcon iconBlack = new ImageIcon("black.jpg");;
    JFrame frame = new JFrame();
    frame.setContentPane(new JPanel(new BorderLayout()));

    JTree tree = new JTree();
    frame.getContentPane().add(tree);

    CustomTreeCellRenderer renderer = new CustomTreeCellRenderer();
    renderer.setRendererIcon(iconWhite);
    tree.setCellRenderer(renderer);

    JPanel panelButtons = new JPanel();

    JButton buttonWhite = new JButton("");
    buttonWhite.setIcon(iconWhite);
    JButton buttonBlack = new JButton("");
    buttonBlack.setIcon(iconBlack);

    buttonBlack.addActionListener(e -> {
      renderer.setRendererIcon(iconBlack);
      tree.repaint();
    });

    panelButtons.add(buttonBlack);
    panelButtons.add(buttonWhite);
    frame.getContentPane().add(panelButtons, BorderLayout.SOUTH);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(500, 500);
    frame.setVisible(true);
  }

  private static class CustomTreeCellRenderer extends DefaultTreeCellRenderer {
    ImageIcon rendererIcon;
    public void setRendererIcon(ImageIcon myIcon) {
      this.rendererIcon = myIcon;
    }
    public Component getTreeCellRendererComponent(JTree tree, Object value,
        boolean selected, boolean expanded, boolean leaf, int row,
        boolean hasFocus) {

      Component ret = super.getTreeCellRendererComponent(tree, value, selected,
          expanded, leaf, row, hasFocus);

      JLabel label = (JLabel) ret;
      label.setIcon(rendererIcon);
      return ret;
    }
  }
}