Java单链表实现 附上两种链表反转到实现方式

前几天因为一个现场演示需要，现场实现手动实现了一个单链表，今天整理临时文件看到了这块代码，就简单整理了一下，发上来记录一下。

/**
 * Created by leon.L on 2018/3/29.
 * Desc : 模拟链表
 */
public class LinkedObj<T> {


    private Node head;

    private Node last;

    private int size = 0;


    class Node<T>{
        T date;
        Node next;
    }

    public LinkedObj() {}

    public void add(T t) {
        Node node = new Node();
        node.date = t;

        if (head == null) {
            head = node;
        } else if (last == null) {
            last = node;
            head.next = last;
        } else {
            Node temp = last;
            temp.next = node;
            last = node;
        }

        size ++;
    }

    public int size() {
        return this.size;
    }

    /**
     * 遍历链表
     */
    public void each(){
        iteritor(head);
    }

    private void iteritor(Node<T> node){
        System.out.println(node.date);

        if (node.next != null) {
            iteritor(node.next);
        }
    }

    /**
     * 链表反转实现1：通过循环实现
     */
    public void reverse(){
        if (size < 2){
            return;
        }

        Node preNode = head;
        last = head;

        Node currentNode = head.next;
        head.next = null;
        Node nextNode ;

        while (currentNode != null) {
            nextNode = currentNode.next;
            currentNode.next = preNode;
            preNode = currentNode;
            currentNode = nextNode;
        }

        head = preNode;
    }

    /**
     * 链表反转实现2：通过递归调用实现
     */
    public void reverse2(){
        doReverse(head, head.next);

        Node t = head;
        head = last;
        last = t;
        last.next = null;

    }

    private void doReverse(Node<T> preNode, Node<T> currentNode){
        if (currentNode == null) {
            return;
        }

        Node next = currentNode.next;
        currentNode.next = preNode;
        doReverse(currentNode, next);
    }


    public static void main(String[] abc){
        LinkedObj<String> list = new LinkedObj<>();

        list.add("11");
        list.add("22");
        list.add("33");
        list.add("44");
        list.add("55");

        list.each();

        list.reverse2();

        list.each();
    }
}