一棵广度和深度都未知的树，存储于数据库的表中，节点存储顺序随机...

public class DeleteNode {
    public static void main(String[] args) {
        Node node = new Node(1, 1, "aa");
        Node node1 = new Node(2, 3, "bb");
        Node node2 = new Node(3, 2, "cc");
        Node node3 = new Node(4, 3, "dd");
        Node node4 = new Node(5, 2, "ee");
        List<Node> list = new ArrayList<>(Arrays.asList(node, node1, node2, node3, node4));
        List<Node> delete = delete(2, list);
        delete.forEach(item -> System.out.println(item.toString()));
    }
    //第一种
    private static List<Node> delete(int targetId, List<Node> nodeList) {
        List<Node> list = new ArrayList<>();
        Stream<Node> nodeStream = nodeList.stream().filter(node -> {
            return (targetId == node.getId() || targetId == node.getParentId());
        });
        nodeList.removeAll(nodeStream.collect(Collectors.toList()));
        list.stream().forEach(node -> {
            delete(node.getId(), nodeList);
        });
        return nodeList;
    }
    //第二种
    private static List<Node> delete1(int targetId, List<Node> nodeList) {
        List<Node> list = new ArrayList<>();
        nodeList.stream().forEach(node -> {
            if (targetId == node.getId() || targetId == node.getParentId()) {
                list.add(node);
            }
        });
        nodeList.removeAll(list);
        list.stream().forEach(node -> {
            delete(node.getId(), nodeList);
        });
        return nodeList;
    }


}