What is the gain from declaring a method as static

Question

I\'ve recently been looking through my warnings in Eclipse and come across this one:

Answer 1

I've no info on the performance, I suppose it is marginally better at most, since the code does not need to do dynamic dispatch based on the type.

However, a much stronger argument against refactoring into static methods is that currently using static is considered bad practice. Static methods / variables do not integrate well into an object oriented language and also, hard to test properly. This is the reason why some newer languages forego the concept of static methods/variables altogether, or try to internalize it into the language in a way that plays better with OO (eg Objects in Scala).

Most of the time, you need static methods to implement functions that are only using parameters as an input and producing an output using that (eg utility/helper functions) In modern languages, there is a first class Function concept that allows that, so static is not needed. Java 8 will have lambda expressions integrated, so we are moving into this direction already.