import javax.swing.JTree;
import javax.swing.tree.TreePath;

public class TreeState {
	public static void setTreeState(JTree tree, boolean expanded) {
		Object root = tree.getModel().getRoot();
		setTreeState(tree, new TreePath(root),expanded);
	}
	
	public static void setTreeState(JTree tree, TreePath path, boolean expanded) {
		Object lastNode = path.getLastPathComponent();
		for (int i = 0; i < tree.getModel().getChildCount(lastNode); i++) {
			Object child = tree.getModel().getChild(lastNode,i);
			TreePath pathToChild = path.pathByAddingChild(child);
			setTreeState(tree,pathToChild,expanded);
		}
		if (expanded) 
			tree.expandPath(path);
		else
			tree.collapsePath(path);
			
		
	}
}