Java枚举链接到另一个枚举 [英] Java Enum linking to another Enum

问题描述

我希望Java中的枚举器具有其他枚举作为属性。

I would like to have enumerator in Java having other enum as attribute.

public enum Direction {
    Up(Down),
    Down(Up),
    Left(Right),
    Right(Left);

    private Direction opposite;

    Direction(Direction opposite){
        this.opposite = opposite;
    }
}

所以我有不同的方向，对于每个我想要的知道相反。
对于Down和Right来说都可以正常工作，但是我无法初始化Up，因为Down未知（左相同的堡垒）。

So I have different Direction, and for each I want to know the opposite. It is working fine for Down and Right, but I can't initialize Up because Down is not known yet (same fort Left).

我怎么能初始化后编辑枚举变量吗？

How can I edit enum variables after initialisation ?

推荐答案

一种可能的解决方案-您可以将该登录名封装在方法中

One of the possible solution - you can encapsulate this login within the method

public Direction getOpposite() {
   switch (this) {
      case Up:
         return Down;
      case Down:
         return Up;
      case Left:
         return Right;
      case Right:
         return Left;
   }
   return null;
}

使用该枚举的类的接口将是相同的

It will be the same interface for classes that will use this enum

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