如何获得枚举值的枚举定义？ [英] How to get Enumeration Value's Enumeration definition?

问题描述

object TestEnum extends Enumeration{
  val One = Value("One")
  val Two,Three= Value
}
println(TestEnum.One.getClass)
println(TestEnum.One.getClass.getDeclaringClass)//get Enumeration

所以我的问题是如何从TestEnum.One获取Class [TestEnum]？

So my question is how to get Class[TestEnum] from TestEnum.One?

谢谢。

推荐答案

我认为您不能不幸。 TestEnum.One 实际上只是类 Enumeration＃Value 的一个实例。实际上，不仅如此，它还差很多-您的枚举值都按类型擦除到同一件事：

I don't think you can unfortunately. TestEnum.One is really just an instance of the class Enumeration#Value. In fact, it's lots worse than just this - your enumeration values are all erased by type to the same thing:

object Weekday extends Enumeration {
  val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
}

def foo(w: Weekday.Value)
def foo(e: TestEnum.Value) //won't compile as they erase to same type

枚举的实例只是 Enumeration＃Value 的实例，它们的声明类仅为 scala.Enumeration 。

As the instances of your enumeration are just instances of Enumeration#Value, their declaring class is just scala.Enumeration.

这令人沮丧，但似乎这些scala枚举比没有用的更糟；如果您通过序列化传递它们（至少在2.7.7中），那么您也不能进行相等性检查！

It's frustrating but it seems like these scala enums are worse than useless; if you pass them through serialization (at least in 2.7.7), then you can't do equality checks either!

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