Why is using static helper methods in Java bad?

Question

I\'m asking because I\'m trying to use a mocking framework (Mockito) which does not allow you to mock static methods. Looking into it I\'ve found quite a few blog posts sayi

Answer 1

This explanation seems to me very straight forward, and easy to understand.

Declare utility methods as static, often makes your code easier to understand, which is a good thing.

But, there is a serious limitation to this approach though: such methods / classes can't be easily mocked.

So if a helper method has any external dependency (e.g. a DB) which makes it - thus its callers - hard to unit test, it is better to declare it non-static.

This allows dependency injection, thus making the method's callers easier to unit test.

Source: https://softwareengineering.stackexchange.com/a/111940/204271