Question

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!

Answer 1

You can put your methods into a utility class, then import that class (not the file!).

import my.useful.UtilityClass;

...
boolean isPrime = UtilityClass.isPrime(2);

When things start to get more complicated, and you want to reuse your stuff across multiple projects, you can put it into a jar and add that jar to the projects. Then you can import and use the class the same way as above.