Factorial in Groovy, Java

Example for versions Groovy 1.7, Sun Java 6, gcj 3.4.5

This example uses iterative calculation of factorial and illustrates the use of built-in class BigInteger which allows to handle arbitrarily large integer numbers. 

import java.math.BigInteger;

public class Factorial {
    public static void main(String[] args)
    {
        BigInteger f = BigInteger.ONE;
        System.out.println("0! = " + f);
        for (int n=1; n<=16; n++)
        {   f = f.multiply(BigInteger.valueOf(n));
            System.out.println( n + "! = " + f);
        }
    }
}