我也问个LinkedHashSet的问题

microjuz

LinkedHashSet继承了hashSet,并且能保持加入元素的顺序。但是看它的源代码只有寥寥4个方法，仅仅覆盖了父类的构造函数，并没有什么特别的？我实在想不通它的如何做到的。

java.util.LinkedHashSet<String>

Hash table and linked list implementation of the Set interface, with predictable iteration order. This implementation differs from HashSet in that it maintains a doubly-linked list running through all of its entries. This linked list defines the iteration ordering, which is the order in which elements were inserted into the set (insertion-order). Note that insertion order is not affected if an element is re-inserted into the set. (An element e is reinserted into a set s if s.add(e) is invoked when s.contains(e) would return true immediately prior to the invocation.)