From 060f1eadb35507f4d8b9a51ae0eb65ac215fc5d4 Mon Sep 17 00:00:00 2001
From: zhenzi <tianzhenzi@inke.cn>
Date: Sat, 15 May 2021 11:02:29 +0800
Subject: [PATCH] =?UTF-8?q?0024=E4=B8=A4=E4=B8=A4=E4=BA=A4=E6=8D=A2?=
 =?UTF-8?q?=E9=93=BE=E8=A1=A8=E4=B8=AD=E7=9A=84=E8=8A=82=E7=82=B9=20?=
 =?UTF-8?q?=E6=B7=BB=E5=8A=A0Java=E5=AE=9E=E7=8E=B0?=
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---
 .../0024.两两交换链表中的节点.md    | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/problems/0024.两两交换链表中的节点.md b/problems/0024.两两交换链表中的节点.md
index 9f07b4f7..0cfa7fb9 100644
--- a/problems/0024.两两交换链表中的节点.md
+++ b/problems/0024.两两交换链表中的节点.md
@@ -86,7 +86,27 @@ public:
 
 
 Java：
+```java
+// 虚拟头结点
+class Solution {
+  public ListNode swapPairs(ListNode head) {
 
+    ListNode dummyNode = new ListNode(0);
+    dummyNode.next = head;
+    ListNode prev = dummyNode;
+
+    while (prev.next != null && prev.next.next != null) {
+      ListNode temp = head.next.next; // 缓存 next
+      prev.next = head.next;          // 将 prev 的 next 改为 head 的 next
+      head.next.next = head;          // 将 head.next(prev.next) 的next，指向 head
+      head.next = temp;               // 将head 的 next 接上缓存的temp
+      prev = head;                    // 步进1位
+      head = head.next;               // 步进1位
+    }
+    return dummyNode.next;
+  }
+}
+```
 
 Python：