验证xyk详细信息

您可以使用以下方法来验证xyk号

// -------------------// Perform Luhn check// -------------------public static boolean isCreditCardValid(String cardNumber) {    String digitsonly = getDigitsonly(cardNumber);    int sum = 0;    int digit = 0;    int addend = 0;    boolean timesTwo = false;    for (int i = digitsOnly.length() - 1; i >= 0; i--) {        digit = Integer.parseInt(digitsOnly.substring(i, i + 1));        if (timesTwo) { addend = digit * 2; if (addend > 9) {     addend -= 9; }        } else { addend = digit;        }        sum += addend;        timesTwo = !timesTwo;    }    int modulus = sum % 10;    return modulus == 0;}