遍历法：

public class ReverseListNode {

    public ListNode Reverse(ListNode root){

        ListNode Cur = root;

        ListNode Pre = null;

        ListNode headNode =null;

        while (Cur!=null){

            ListNode next=Cur.next;

            if(next==null)

                headNode = Cur;

            Cur.next = Pre;

            Pre = Cur;

            Cur = next;

        }

        return headNode ;

    }

 

    public static void main(String[] args) {

        ListNode root=new ListNode(1);

        root.next=new ListNode(2);

        ListNode R=new ReverseListNode().Reverse(root);

    }

}

class ListNode {

 

    public int val;

    public ListNode next;

 

    public ListNode(int x) {

        val = x;

    }

}

递归实现：

package TEST.反转链表;/** * Created by nick on 2018/10/9. */public class reverseLinkedList {    static ListNode reverseLinkedList(ListNode node) {        if (node == null || node.next == null) {            return node;        } else {            ListNode headNode = reverseLinkedList(node.next);            node.next.next = node;//headNode和node是两个相交的链表            node.next = null;            return headNode;        }    }    public static void main(String[] args) {        ListNode root=new ListNode(1);        root.next=new ListNode(2);        root.next.next=new ListNode(3);        ListNode R=reverseLinkedList(root);    }}