leetcode-Java-83. Remove Duplicates from Sorted List

public class Solution {
public ListNode deleteDuplicates(ListNode head) {
ListNode node = head;
if(head == null || head.next ==null) {
return head;
}
while(node!=null) {
while(node.next !=null && node.next.val == node.val) {
node.next = node.next.next;
}
node = node.next;
}

return head;
}
}