【Leetcode】Delete Node in a LinkedList

【题目】

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 

1 -> 2 -> 3 -> 4

 and you are given the third node
with value 

3

, the linked list should become 

1
-> 2 -> 4

 after calling your function.
【思路】
The idea is to copy the data of next node to current node and then delete the next node.

【代码】

/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public void deleteNode(ListNode node) {
if(node!=null && node.next !=null){
node.val = node.next.val;
node.next = node.next.next;
}
}
}

为什么不能直接吧当前节点变成次啊一个节点？！！！