ArrayList nodes = new ArrayList(); DefaultTreeNode rootNode = new DefaultTreeNode(null, nodes); DefaultTreeModel treeModel = new DefaultTreeModel(rootNode); int counter = 0; public void refreshTreeModel() { rootNode.getChildren().clear(); rootNode.add(new DefaultTreeNode("" + (++counter))); rootNode.add(new DefaultTreeNode("" + (++counter))); } public void rerenderRadioGroup() { winContent.getChildren().clear(); winContent.getTemplate("radioGroup").create(winContent, null, null, null); }