枚举中的静态最终方法

Question

So I have looked around google and SO , I cannot find a example or explanation of : What is the purpose of static final methods in enum ?

What I understand :

1. Methods declare static can be accessed like function/procedural languages.
2. final means you can't override it. Can't change the reference. As assylias pointed out in comments static can't be overridden either.
3. enum s can't be subclassed, explained here .

So what's the point of static final methods in enum s if it will never be overridden since there won't be a subclass?

Answer 1

By making a static method final, you prevent it from being hidden (only instance methods can be overriden) by a subclass.

Since enum can't be subclassed, making a static method final is superfluous but not forbidden.

Note: technically, each enum constant that has a class body implicitly defines an anonymous class that extends the enum . But since inner classes may not declare static methods , the static final method could not be hidden in such a constant's class body.

Answer 2

It's easy to see why static methods make sense, so I guess the question is about the final modifier.

final serves no purpose here, except maybe make the code a bit easier to read, but not by much.

It's similar to the way interface methods are often written as public void foo(); , even though interface members are always public anyway.

Answer 3

在Java中，Enum类型用于表示固定的常量集，并使其成为静态final，仅帮助其初始化一次，单个副本在所有实例之间共享，使用类名访问变量，最后更像是只读

Answer 4

When you declare instances of an enum you can override the enum's methods, essentially enum instances are implemented as (or thought of) as subclasses. static methods can't be overridden in any case but the implication in the OP and other answers that final is superfluous for an enum is false.