ArrayList 중복 제거 및 순차 정렬 함수

public List removeDuplicateWithOrder(ArrayList arlList) { 

HashSet set = new HashSet(); 

 List newList = new ArrayList(); 

 for (Iterator iter = arlList.iterator();    iter.hasNext(); ) { 

  Object element = iter.next(); 

  if (set.add(element)) newList.add(element); 

 } 

 arlList.clear(); 

 arlList.addAll(newList);

 

 return arlList;

}