swap nodes in pairs(nodes not values)

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode swapPairs(ListNode head) {
        ListNode temp = new ListNode(0);
        temp.next = head;
        ListNode curr = temp;
        while(curr.next != null && curr.next.next != null){
            ListNode first = curr.next;
            ListNode second = curr.next.next;
            first.next = second.next;
            second.next = first;
            curr.next = second;
            curr.next.next = first;
            curr = first;
        }
        return temp.next;
    }
}