JTree的setRoot（）时ClassNotLoadedException

Question

当我尝试将ClassNotLoadedException设置为JTree的根时，我有一个treeModel.setRoot(treeNode)。

我的代码：

public static DefaultMutableTreeNode parse(JTree tree, JScrollPane scrollPane, TreeCellRenderer renderer, mySAXParser SAXParser, String newXML) {
    DefaultMutableTreeNode treeNode;
    mySAXParser parser = SAXParser;
    treeNode = parser.getTreeNode();
    tree.setCellRenderer(renderer);

    DefaultTreeModel treeModel = (DefaultTreeModel) tree.getModel();
    treeModel.setRoot(treeNode);
    TreeSelectionModel treeSelectionModel = tree.getSelectionModel();
    treeSelectionModel.setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);

    tree.setSelectionModel(treeSelectionModel);
    scrollPane.setEnabled(true);
    expandTree(tree);

    return treeNode;
}

初​​始化：

myTree = new JTree();
((DefaultTreeModel) myTree.getModel()).setRoot(null);
scrollPane= new JScrollPane(myTree);

完整的异常消息：

org.eclipse.debug.core.DebugException: com.sun.jdi.ClassNotLoadedException: Type has not been loaded occurred while retrieving component type of array.

我不明白为什么会这样，有人能帮助我理解吗？