I'm learning Java and OOP, and have been doing the problems at Project Euler for practice (awesome site btw).

I find myself doing many of the same things over and over, like:

• checking if an integer is prime/generating primes
• generating the Fibonacci series
• checking if a number is a palindrome

What is the best way to store and call these methods? Should I write a utility class and then import it? If so, do I import a .class file or the .java source? I'm working from a plain text editor and the Mac terminal.

Thanks!