参考：http://kwon.iteye.com/blog/749643
public static void expandTree(JTree tree) {
TreeNode root = (TreeNode) tree.getModel().getRoot();
expandAll(tree, new TreePath(root), true);
}
private static void expandAll(JTree tree, TreePath parent, boolean expand) {
// Traverse children
TreeNode node = (TreeNode) parent.getLastPathComponent();
if (node.getChildCount() >= 0) {
for (Enumeration e = node.children(); e.hasMoreElements(); ) {
TreeNode n = (TreeNode) e.nextElement();
TreePath path = parent.pathByAddingChild(n);
expandAll(tree, path, expand);
}
}
// Expansion or collapse must be done bottom-up
if (expand) {
tree.expandPath(parent);
} else {
tree.collapsePath(parent);
}
}
