import java.util.Enumeration;
import javax.swing.JTree;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
public class Main {
public void expandAll(JTree tree) {
TreeNode root = (TreeNode) tree.getModel().getRoot();
expandAll(tree, new TreePath(root));
}
private void expandAll(JTree tree, TreePath parent) {
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);
}
}
tree.expandPath(parent);
// tree.collapsePath(parent);
}
}