title: How to use java methods defined in another class/file
body: <p>I've been working on some problems from Project Euler, and, in the process, have written a lot of useful methods (in Java) that I might like to use in other Java projects. I want to be able to call them in the way that you call a function from java.lang.math, so if I had a method primeFactor() I could call it using <code>MyMathMethods.primeFactor(number)</code>. How would I go about this? Would I make some kind of package that I could import? Would I make a superclass that includes all my useful math-y functions and have whatever class I'm working with in a new project extend that? There are probably multiple ways to do this, but I don't know what is best. Thanks in advance.</p>