Java Swing JTree:如何在最后创建的节点上改变焦点

DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
DefaultMutableTreeNode child1 = new DefaultMutableTreeNode("Child 1");
DefaultMutableTreeNode child2 = new DefaultMutableTreeNode("Child 2");
DefaultMutableTreeNode child3 = new DefaultMutableTreeNode("Child 3");

root.add(child1);
root.add(child2);
root.add(child3);

JTree tree = new JTree(root);

int lastIndex = tree.getRowCount() - 1;
tree.setSelectionRow(lastIndex);

TreePath path = tree.getPathForRow(lastIndex);

tree.setSelectionPath(path);