Is there a rule of thumb for when to code a static method vs an instance method?

Question

I\'m learning Java (and OOP) and although it might irrelevant for where I\'m at right now, I was wondering if SO could share some common pitfalls or good design practices.

Answer 1

If it uses an instance variable it must be an instance method.

If not, it's up to you, but if you find yourself with a lot of static methods and/or static non-final variables, you probably want to extract all the static stuff into a new class instance. (A bunch of static methods and members is a singleton, but a really annoying one, having a real singleton object would be better--a regular object that there happens to be one of, the best!).