printing unique elements in two lists

import java.util.*;
import java.lang.*;
public class MultipleList{

public void printUnique(ArrayList<Integer> list1,ArrayList<Integer> list2){

ArrayList<Integer> aList1 = list1;
ArrayList<Integer> aList2 = list2;
ListIterator<Integer> iterator1 = aList1.listIterator();
ListIterator<Integer> iterator2 = aList2.listIterator();

while(iterator1.hasNext() || iterator2.hasNext()){
if(iterator1.hasNext() && iterator2.hasNext()){
int num1 = iterator1.next();
int num2 = iterator2.next();
if(num1 < num2){
System.out.println(num1);
iterator2.previous();}
if(num1 > num2){
System.out.println(num2);
iterator1.previous();
}
}
else if(iterator1.hasNext()){
System.out.println(((Integer)iterator1.next()).intValue());
}
else if(iterator2.hasNext()){
System.out.println(((Integer)iterator2.next()).intValue());
}
}
}
public static void main (String args[]){
MultipleList list = new MultipleList();
 ArrayList<Integer> list1 = new ArrayList<Integer>();
 ArrayList<Integer> list2 = new ArrayList<Integer>();
list1.add(2);list1.add(6);list1.add(8);list1.add(10);

list2.add(2);list2.add(4);list2.add(6);list2.add(12);list2.add(18);

list.printUnique(list1,list2);

}
}