Java 从自定义渲染器中获取方法GetTreeCellRenderComponent中的JTree节点文本

我正在自定义JTree，以便某些节点具有复选框，用作基础

因此，我们的想法是编写一个定制的TreeCellRenderer，在本例中它扩展了JPanel并实现了TreeCellRenderer，然后在方法GetTreeCellRenderComponent中，我必须为每个节点决定是否接收复选框

我已经看到了一些典型JTree自定义每个节点图标的其他示例，但它们依赖于将每个节点转换为JLabel并获取其文本，而这里是JPanel

这是我的渲染器的外观：

public class CheckTreeCellRenderer extends JPanel implements TreeCellRenderer{

    private CheckTreeSelectionModel selectionModel;
    private TreeCellRenderer delegate;
    private TristateCheckBox checkBox;
    protected CheckTreeManager.CheckBoxCustomizer checkBoxCustomer;


    public CheckTreeCellRenderer(TreeCellRenderer delegate, CheckTreeSelectionModel selectionModel){
        this.delegate = delegate;
        this.selectionModel = selectionModel;
        this.checkBox = new TristateCheckBox("");
        this.checkBox.setOpaque(false);
        setLayout(new BorderLayout());
        setOpaque(false);
    }


    public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus){
        Component renderer = delegate.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);

        // Inside this if clause, those cells which do not require checkbox will be returned
        if({CODE_TO_GET_NODE_TEXT}.startsWith("A")){
            return renderer;
        }

        TreePath path = tree.getPathForRow(row);
        if(path != null){
            if(checkBoxCustomer != null && !checkBoxCustomer.showCheckBox(path)){
                return renderer;
            }
            if(selectionModel.isPathSelected(path, selectionModel.isDigged())){
                checkBox.getTristateModel().setState(TristateState.SELECTED);
            }
            else{
                checkBox.getTristateModel().setState(selectionModel.isDigged() && selectionModel.isPartiallySelected(path) ? TristateState.INDETERMINATE : TristateState.DESELECTED);
            }
        }
        removeAll();
        add(checkBox, BorderLayout.WEST);
        add(renderer, BorderLayout.CENTER);

        return this;
    }
}

在本例中，我希望避免为文本以“a”开头的单元格设置三态复选框作为示例。但是我找不到从value参数中获取文本的方法

如果有帮助，以下是我创建JTree的方式：

DefaultMutableTreeNode root = new DefaultMutableTreeNode();
JTree tree = new JTree(root);

// Add nodes to the tree
DefaultMutableTreeNode friends_node = new DefaultMutableTreeNode("Friends");
    friends_node.add(new DefaultMutableTreeNode("Anna"));
    friends_node.add(new DefaultMutableTreeNode("Amador"));
    friends_node.add(new DefaultMutableTreeNode("Jonas"));
    friends_node.add(new DefaultMutableTreeNode("Mike"));
    friends_node.add(new DefaultMutableTreeNode("Anthony"));
    friends_node.add(new DefaultMutableTreeNode("Maya"));
    friends_node.add(new DefaultMutableTreeNode("Pepe Vinyuela"));
root.add(friends_node);

tree.setCellRenderer(renderer = new CheckTreeCellRenderer(tree.getCellRenderer(), new CheckTreeSelectionModel(tree.getModel(), dig)));

---

有什么想法吗？

如果您使用的是

String userObject=“Anna”，则可以使用以下方法：

@Override public Component getTreeCellRendererComponent(
    JTree tree, Object value, boolean selected, boolean expanded,
    boolean leaf, int row, boolean hasFocus) {
  Component renderer = delegate.getTreeCellRendererComponent(
    tree, value, selected, expanded, leaf, row, hasFocus);
  if (value instanceof DefaultMutableTreeNode) {
    Object userObject = ((DefaultMutableTreeNode) value).getUserObject();
    // Inside this if clause, those cells which do not require checkbox will be returned
    if(userObject instanceof String && ((String) userObject).startsWith("A")){
      return renderer;
    }
    //...