将接口的实现者强制为枚举 [英] Enforcing the implementer of an interface to be an enum

问题描述

我想在一个集合中存储一个名为 App 的类型。 应用程序需要是实现 App 界面的枚举。

 组<应用>安装MyApps; 
  

我已经定义了这样的界面...

 界面App< T extends Enum< T>> {} 
  

这几乎工作，例如，你不能这样做...

  class MyClass实现Application&MyClass> {} 
  

但是，你可以这样做...

 枚举MyEnum实现应用程序< MyEnum> {} 
 class Myclass实现Application< MyEnum> {} 
  

哪个错误。我只想要枚举能够实现这个界面，我该如何执行？

解决方案

定义一个方法，将元素添加到集合中，但使用该参数的约束...

  public< E extends Enum&E; &安培; IMyInterface的> void addToSet（final E value）{} 
  

此后

  addToSet（MyEnum.K）将编译
  

但是

  addToSet（new Myclass（））不会编译
  pre> 
I would like to store a type called App inside a set. App needs to be an enum that implements the App interface.
Set<App> myApps;
I have defined the interface like so...
interface App<T extends Enum<T>> {}
This is almost working, for example, you cannot do this...
class MyClass implements Application<MyClass> {}
However, you can do this...
enum MyEnum implements Application<MyEnum> {}
class Myclass implements Application<MyEnum> {}
Which is wrong. I only want enums to be able to implement this interface, how can I enforce this?
解决方案
Define a method that allows you to add Elements into the set, BUT use a constraint for that parameter...
 public <E extends Enum<E> & IMyInterface> void addToSet(final E value) { }
now after that 
addToSet(MyEnum.K) will compile
but 
addToSet(new Myclass()) will NOT compile


                        
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