Leetcode--Remove Linked List Elements

Remove all elements from a linked list of integers that have value val.

Example
Given: 1 –> 2 –> 6 –> 3 –> 4 –> 5 –> 6, val = 6
Return: 1 –> 2 –> 3 –> 4 –> 5

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ListNodes {
       public int val;
         public ListNodes next;
         public ListNodes(int x) { val = x; }
         public ListNodes(int x,ListNodes nexts) { val = x; next=nexts;}
         public ListNodes removeElements(ListNodes head, int val) {


             if(head==null)
             return head;

             while(head!=null&&head.val==val)
             {
                 head=head.next;
             }

             ListNodes post=null;
             ListNodes cur=head;
             ListNodes tmp=null;
             while(cur!=null)
             {
                 if(cur.val==val)
                 {

                         post.next=cur.next;
                         cur=post.next;


                 }
                 else
                 {

                     post=cur;
                     cur=cur.next;
                 }
             }

             return head;
         }
     }