我需要一个 Java泛型类来表示任何类型的无序对。同时我看到两个解决方案:
HashSet
存储对元素- 一个
Pair
具有覆盖hashCode
和equals
(使Pair(a, b)
和Pair(b, a)
相等)的类。
是否有意义?你有什么建议?
我需要一个 Java泛型类来表示任何类型的无序对。同时我看到两个解决方案:
HashSet
存储对元素Pair
具有覆盖hashCode
和equals
(使Pair(a, b)
和Pair(b, a)
相等)的类。是否有意义?你有什么建议?
In your place I would roll out my own class. As long as you are interested in sets of only two objects, using HashMap
, HashSet
(which, incidentally, uses a HashMap
internally anyway) or any other class designed for sets of arbitrary cardinality is a waste of resources and adds unneeded complexity.
Just create your own class with proper equals()
and hashCode()
implementations. Having a contains()
operation, or even implementing parts of the Set
interface, might also make sense.
One important note: make sure you document your class extensively - at least specify whether equals()
performs an identity or an equality comparison for the contained objects, and what is the meaning of a null
contained reference...