使用Java泛型时出错?扩展条款

使用Java泛型时出错?扩展条款,java,generics,Java,Generics,我有一个treeitem对象,其用户对象类型为MyNode: final TreeItem<? extends MyNode> parent = treeItem.getParent(); final ObservableList<TreeItem<? extends MyNode>> children = parent.getChildren(); 有什么建议吗?试试: final ObservableList<? extends TreeItem&

我有一个treeitem对象,其用户对象类型为
MyNode

final TreeItem<? extends MyNode> parent = treeItem.getParent();
final ObservableList<TreeItem<? extends MyNode>> children = parent.getChildren();
有什么建议吗?

试试:

final ObservableList<? extends TreeItem<? extends MyNode>> children = parent.getChildren();
最终可观察列表
final ObservableList<? extends TreeItem<? extends MyNode>> children = parent.getChildren();