Should a java class' final fields always be static?

Question

I could not find any references online about this. But just wanted to know if final fields in a class should always be static or is it just a convention. Based

Answer 1

Final fields do not need to be static, and sometimes it can be useful to have a non-static final instance variable. Fields that are marked both static and final are usually used for constants, like this:

public static final int BORDER_WIDTH = 5;

However, sometimes you'll see a non-static final field when an object has a immutable property. Usually, non-static final fields are still marked private for the usual reasons, though, so it's more of an extra check so the compiler can make sure you're never setting the property again.