Class with only static methods - Enum or not

Question

Time after time I have a situation where I have an utility class containing only static methods.

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The question is not about the fact of having such classes themselfes, so not a debate about utility classes. We just assume that there is a use case where this class makes sense.

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Now I have seen different possibilities to prevent instantiation/extension:

• a private constructor and final class
• using an enum instead of a class

What is the best practice here? Could you elaborate the benefits/drawbacks of the two possibilities?

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Personally I prefer the enum solution, as it completely prevents instantiation and extension out of the box, but maybe I am wrong.

Thank you already!

Answer 1

I would prefer the former.

First of all, using a final class with a private constructor is what I do all the time when I'm writing a utility class. I have never even thought of using enums.

The main reason for not using an enum is that you can still technically write something like this:

MyEnum var = MyEnum.valueOf("Hello");

and the compiler doesn't say a thing about it, not even IntelliJ IDEA!