public class FactorialRec {

    public static int factorial(int n) {

        if (n == 1) {
            return 1;
        }

        return n * factorial(n-1);

    }

    public static void main(String[] args) {

        System.out.println(factorial(0));
        
    }

}

// > java FactorialRec
// Exception in thread "main" java.lang.StackOverflowError
// 	at FactorialRec.factorial(FactorialRec.java:9)

// > java FactorialRec 2>&1 > /dev/null | grep -c 'at FactorialRec.factorial'
// 1024

// > java FactorialRec 2> /dev/stdout 1> /dev/null | grep -c 'at FactorialRec.factorial'
// 1024