Java实现双向链表

java实现双向链表的基本功能

双向链表也叫双链表，是链表的一种，它的每个数据结点中都有两个指针，分别指向直接后继和直接前驱。所以，从双向链表中的任意一个结点开始，都可以很方便地访问它的前驱结点和后继结点

代码实现：

双向链表的添加结点和删除结点的方法和单向链表有所不同，具体看下方的代码

public class DoubleLInkedListDemo {
    public static void main(String[] args) {


        HeroNode2 hero1 = new HeroNode2(1, "林冲", "豹子头");
        HeroNode2 hero2 = new HeroNode2(2, "宋江", "及时雨");
        HeroNode2 hero3 = new HeroNode2(3, "吴用", "智多星");
        HeroNode2 hero4 = new HeroNode2(4, "卢俊义", "玉麒麟");

        DoubleLinkedList doublelist = new DoubleLinkedList();

        doublelist.addLinkedList(hero1);
        doublelist.addLinkedList(hero2);
        doublelist.addLinkedList(hero3);
        doublelist.addLinkedList(hero4);

        System.out.println("双向链表的信息为：");
        doublelist.showLinkedList();

        System.out.println("双向链表跟新后的信息为：");
        hero2.name = "小宋";
        hero2.nickname = "下雨";
        doublelist.update(hero2);
        doublelist.showLinkedList();

        System.out.println("删除某个结点后的信息为：");
        doublelist.delet(hero2);
        doublelist.showLinkedList();


    }
}


class DoubleLinkedList {
    HeroNode2 head = new HeroNode2(0, "", "");

    public void addLinkedList(HeroNode2 hero) {
        //创建一个辅助节点
        HeroNode2 temp = head;


        while (true) {
            if (temp.next == null) {
                break;
            }
            temp = temp.next;
        }

        temp.next = hero;
        hero.pre = temp;
    }

    public void update(HeroNode2 hero) {
        //首先判断链表是否为空
        if (head.next == null) {
            System.out.println("链表为空，修改数据失败。");
        }
        //创建辅助节点
        HeroNode2 temp = head.next;
        while (temp != null) {
            if (temp.no == hero.no) {
                temp.name = hero.name;
                temp.nickname = hero.nickname;
                break;
            }
            temp = temp.next;
        }
    }

    //删除节点  根据编号进行删除节点，删除后的节点 idea的垃圾回收机制会进行回收
    public void delet(HeroNode2 hero) {
        HeroNode2 temp = head.next;
        while (true) {
            if (temp == null) {
                System.out.println("链表为空，删除节点失败");
                break;
            }
            if (temp.no == hero.no) {
                temp.next.pre = temp.pre;
                temp.pre.next = temp.next;
                break;
            }
            temp = temp.next;
        }
    }

    public void showLinkedList() {
        if (head.next == null) {
            System.out.println("链表为空。");
            return;
        }
        HeroNode2 term = head.next;
        while (true) {
            System.out.println(term);
            term = term.next;
            if (term == null) {
                break;
            }
        }
    }


}

class HeroNode2 {
    public int no;
    public String name;
    public String nickname;
    HeroNode2 next;
    HeroNode2 pre;

    HeroNode2(int no, String name, String nickname) {
        this.no = no;
        this.name = name;
        this.nickname = nickname;
    }

    @Override
    public String toString() {
        return "HeroNode{" +
                "no=" + no +
                ", name='" + name + '\'' +
                ", nickname='" + nickname + '\'' +
                '}';
    }
}