LinkedHashSet-插入顺序和重复项-保持最新状态为“最重要”

大多数Java集合都可以扩展以进行调整。

子类

linkedHashSet

add

class TweakedHashSet<T> extends linkedHashSet<T> {    @Override    public boolean add(T e) {        // Get rid of old one.        boolean wasThere = remove(e);        // Add it.        super.add(e);        // Contract is "true if this set did not already contain the specified element"        return !wasThere;    }}