对于equals和compareTo是否有意义是不一致的？ [英] Does it make sense for equals and compareTo to be inconsistent?

问题描述

我想让一个类在 SortedSet |中可用 SortedMap 。

I want to make a class usable in SortedSet | SortedMap.

class MyClass implements Comparable<MyClass>{
  // the only thing relevant to comparisons:
  private final String name;

  //...
}

<实例必须按其名称属性排序。

但是，我不希望同名的实例被视为相等。

The class' instances must be sorted by their name property.
However, I don't want equally named instances to be considered as equal.

code> SortedSet 内容将类似于 a，a，a，b，c 。

（通常， SortedSet 只允许 a，b，c ）

So a SortedSet content would look like a, a, a, b, c.
(Normally, SortedSet would only allow a, b, c)

首先： ）一致？

First of all: is this (philosophically) consistent?

如果是这样，我不得不指望不可预测的行为，当我不
覆盖等于（...）和 hashCode（）？

If so, do I have to expect unpredictable behavior, when I don't override equals(...) and hashCode()?

对不起，我的问题似乎不一致：

我要在设置中添加多个 / strong>，这不允许这个
的概念。

所以，请不要回复我的问题。

感谢所有已经回复。

I am sorry, my question seems inconsistent:
I want to put multiple "equal" values inside a set, which doesn't allow this by concept.
So, please don't reply to my question anymore.
Thanks to all who already replied.

推荐答案

让我问一个问题： a.compareTo（b） return 0 and a.equals（b） return false ？

Let me ask you a question: does it make sense to have a.compareTo(b) return 0 and a.equals(b) return false?

我会使用 Comparator< MyClass> 。这就是为什么所有 SortedMap / SortedSet 我知道的实现允许你传递 Comparator 。

I would use a Comparator<MyClass> instead. This is why all SortedMap/SortedSet implementations that I know of allow you to pass in a Comparator at creation.

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