JTreeの展開、折畳みアイコンを非表示にする

Icon emptyIcon = new Icon() {
  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    /* Empty icon */
  }

  @Override public int getIconWidth() {
    return 0;
  }

  @Override public int getIconHeight() {
    return 0;
  }
};
UIManager.put("Tree.expandedIcon", new IconUIResource(emptyIcon));
UIManager.put("Tree.collapsedIcon", new IconUIResource(emptyIcon));