Java Utility Class to generate Canadian SINs

SinGenerator.java

import java.util.Arrays;
import java.util.Random;
import java.util.stream.Collectors;

/**
 * Helper class to create SINs
 * @author Peter Newhook
 *
 */
public class SinGenerator {
    // generate a SIN following the Luhn Algorithm
    public static String generateSin() {
    	int[] originalDigits = new int[9];

    	Random r = new Random();
    	// fill initializing values, skipping the last value because that'll be the check
    	for (int i = 0; i < originalDigits.length - 1; i++) {
    		// don't allow the first digit to be 9 because that's a temp sin
    		if (i == 0) {
				originalDigits[i] = r.nextInt(9);
			}else {
				originalDigits[i] = r.nextInt(10);
			}
		}
    	int[] doubledDigits = originalDigits.clone();
    	
    	// double every other digit
    	for (int i = 1; i < originalDigits.length; i+=2) {
			int currentValue = originalDigits[i];
			int doubled = currentValue * 2;
			
			doubledDigits[i] = doubled > 9 ? doubled - 9 : doubled;
		}
    	
    	int sum = Arrays.stream(doubledDigits).sum();
    	
    	int checkDigit = ((sum * 9) % 10);
    	originalDigits[8] = checkDigit;
    	return Arrays.stream(originalDigits).mapToObj(String::valueOf).collect(Collectors.joining());
    }
}