java的List中的对象如何去重

// 删除ArrayList中重复元素，保持顺序 

public    static    void   removeDuplicateWithOrder(List list)   {
      Set set  =    new   HashSet();
      List newList  =    new   ArrayList();
   for   (Iterator iter  =  list.iterator(); iter.hasNext();)   {
         Object element  =  iter.next();
         if   (set.add(element))
            newList.add(element);
     }
     list.clear();
     list.addAll(newList);
     System.out.println(  " remove duplicate "    +  list);
}