总结了两种删除ArrayList中重复元素的方法。

方法一：

// 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);
}

方法二：

public static ArrayList removeDuplicate(ArrayList al){
	ArrayList newAl = new ArrayList();
	for(Iterator it = al.iterator(); it.hasNext();)
	{
		Object obj = it.next();
		if(!newAl.contains(obj))
		{
			newAl.add(obj);
		}
	}
	return newAl;
}