Project Euler 25 - 1000 digit Fibonacci Sequence (JAVA)

package euler25;

public class ThousandDigitFibonacci {

    private static int index = 1;
    private static final int stop = 1000;

    public static void main(String[] args) {

        long startTime = System.currentTimeMillis();

        int n1 = 0;
        int n2 = 1;
        fibonacciSequence(n1, n2);

        long endTime = System.currentTimeMillis();
        System.out.println("Time: " + (endTime - startTime) + " ms");
    }

    public static void fibonacciSequence(int n1, int n2) {

        System.out.println("F" + index + " = " + n2);
        if(countDigits(n1) == 1000) {
            return;
        }
        index++;

        fibonacciSequence(n2, n1+n2);
    }

    public static int countDigits(int fibNum) {
         int length = String.valueOf(fibNum).length();
         return length;
    }
}