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两种方法删除ArrayList里重复元素

这里有两种方法帮你删除在一个ArrayList里重复的elements。下面的程序片段里,removeDuplicate方法不维护顺序 (Order),而removeDuplicateWithOrder方法会保持顺序 (Order),但会有些性能上的牺牲。

The removeDuplicate Method:

/** List order not maintained **/  public static void removeDuplicate(ArrayList arlList)  {   HashSet h = new HashSet(arlList);   arlList.clear();   arlList.addAll(h);  }

The removeDuplicateWithOrder Method:

/** List order maintained **/public static void removeDuplicateWithOrder(ArrayList arlList) { Set 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);}

两种方法删除ArrayList里重复元素