java - 为什么我们可以使用 'new' 关键字来获取非静态外部类中静态内部类的引用？

Question

从下面的代码中可以看到，我们编写RemoveDups_1.LinkedList linkedList = new RemoveDups_1.LinkedList();来获取非静态类RemoveDups_1内的静态类LinkedList的实例。既然这是一个静态类，为什么我们需要使用 new 关键字来获取 LinkedList 类的实例？

import java.util.*;

public class RemoveDups_1{
    public static class LinkedList{

        static int i = 5;

        class Node{
            int data;
            Node next;

            public Node(int data){
                this.data = data;
            }
        }

        Node head;

        public void appendToTail(int data){
            if(head == null){
                head = new Node(data);
            }
            else{
                Node node_to_append = new Node(data);
                Node node = head;
                while(node.next != null){
                    node = node.next;
                }
                node.next = node_to_append;
            }
        }
    }



    public static void main(String[] args){

        RemoveDups_1 removeDups_1 = new RemoveDups_1();
        RemoveDups_1.LinkedList linkedList = new RemoveDups_1.LinkedList();     
        RemoveDups_1.LinkedList.Node node;
        node = linkedList.new Node(3);

        System.out.println(RemoveDups_1.LinkedList.i);

    }
}

Answer 1

LinkedList 是嵌套类，您需要它是静态的，以便实例化它，而不需要创建其外部类的实例