public void treeExpanded(TreeExpansionEvent event) { TreePath treePath = event.getPath(); if (treePath != null) { TreeUINode targetNode = (TreeUINode) treePath.getLastPathComponent(); if (!targetNode.isChildrenLoaded()) { String targetPathText = TreeUtil.makePathText(treePath); String absPathText = PathUtil.makeChildPath(_tree.getRelativeRoot(), targetPathText); expandNode(targetNode, absPathText); } } }