java容器---------手工实现Linkedlist 链表

第一版：增加add方法

package cn.zxg.collection;

public class Node {
    Node previous;//上个节点
    Node next;//下个节点
    Object element;//自己的数据
    public Node(Node previous,Node next,Object element){
        this.previous=previous;
        this.next=next;
        this.element=element;

    }

    public  Node(Object element){
        this.element=element;
    }
}

package cn.zxg.collection;

/**
 * 自定义一个链表，增加一个add方法
 */

public class SxtLinkList {

    private Node first;
    private  Node last;
    private  int size;
    public void add(Object obj){
        Node node=new Node(obj);
        if(first==null){
            first=node;
            last=node;
        }else {
            node.previous=last;
            node.next=null;

            last.next=node;
            last=node;
        }

    }

    public String toString() {
        StringBuilder sb=new StringBuilder();
        sb.append("[");
        Node temp=first;
        while (temp!=null){
            sb.append(temp.element+",");
            temp=temp.next;
        }
        sb.setCharAt(sb.length()-1,']');
        return sb.toString();
    }


    public static void main(String[] args) {
        SxtLinkList list=new SxtLinkList();
        list.add("a");
        list.add("b");
        list.add("c");
        System.out.println(list.toString());
    }
}


第二版、添加get方法，传入索引返回对应的内容