具有自引用类型约束的泛型类

public class TreeNode<T extends TreeNode<T>> {
    private T parent;
    private List<T> children;

    public TreeNode() {
        children = new ArrayList<>();
    }

    public T getParent() {
        return parent;
    }

    public void setParent(T parent) {
        this.parent = parent;
    }

    public List<T> getChildren() {
        return children;
    }

    public void addChild(T child) {
        children.add(child);
        child.setParent(this);
    }
}