How to validate iranian Melli Code (National Code or Code Melli) in android

Question

I need a method to validate the Melli Code (National Code or Code Melli) of iranian people.

I Know it has a formula.

Answer 1

Java 8

import java.util.stream.Streams;
import java.util.function.IntUnaryOperator;
public static boolean isValidIranianNationalCode(String input) {
if (!input.matches("^\\d{10}$"))
    return false;

int check = Integer.parseInt(input.substring(9, 10));

int sum = IntStream.range(0, 9)
        .map(x -> Integer.parseInt(input.substring(x, x + 1)) * (10 - x))
        .sum() % 11;

return (sum < 2 && check == sum) || (sum >= 2 && check + sum == 11);
}