JTreeのノード展開・折り畳み状態をキー入力で切り替える

InputMap im = tree.getInputMap(JComponent.WHEN_FOCUSED);
int modifiers1 = InputEvent.CTRL_DOWN_MASK;
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_T, modifiers1), "toggle");
int modifiers2 = InputEvent.CTRL_DOWN_MASK | InputEvent.SHIFT_DOWN_MASK;
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_T, modifiers2), "toggle2");
ActionMap am = tree.getActionMap();
am.put("toggle2", new AbstractAction() {
  @Override public void actionPerformed(ActionEvent e) {
    int row = tree.getLeadSelectionRow();
    TreePath path = tree.getPathForRow(row);
    if (!tree.isExpanded(path)) {
      tree.expandPath(path);
    } else {
      tree.collapsePath(path);
    }
  }
});