javafx treeview 获取选中的结点

int dex=foldertree.getSelectionModel().getSelectedIndex();

                获取选中的结点下标

                foldertree.getSelectionModel().selectedItemProperty().addListener(
                    new ChangeListener<TreeItem <String>>() {
                    @Override
                    public void changed(ObservableValue<? extends TreeItem<String>> observableValue,
                    TreeItem<String> oldItem, TreeItem<String> newItem) {
                        System.out.println(newItem.getValue());
                    }
                });将侦听器加入到结点