xbeginagain / generator Goto Github PK

    boolean b = helloWorld.validate18("12440600MB2C07549J");
    System.out.println(b);
}

public boolean validate18(String bizNo) {

    String regex = "^([0-9ABCDEFGHJKLMNPQRTUWXY]{2})([0-9]{6})([0-9ABCDEFGHJKLMNPQRTUWXY]{10})$";
    if (!bizNo.matches(regex)) {
        return false;
    }

    String baseCode = "0123456789ABCDEFGHJKLMNPQRTUWXY";
    char[] baseCodeArray = baseCode.toCharArray();
    Map<Character, Integer> codes = new HashMap<Character, Integer>();
    for (int i = 0; i < baseCode.length(); i++) {
        codes.put(baseCodeArray[i], i);
    }

    char[] businessCodeArray = bizNo.toCharArray();
    Character check = businessCodeArray[17];
    if (baseCode.indexOf(check) == -1) {
        return false;
    }

    int[] ws = { 1, 3, 9, 27, 19, 26, 16, 17, 20, 29, 25, 13, 8, 24, 10, 30, 28 };
    int sum = 0;
    for (int i = 0; i < 17; i++) {
        Character key = businessCodeArray[i];
        if (baseCode.indexOf(key) == -1) {
            return false;
        }
        sum += (codes.get(key) * ws[i]);
    }

    int c18 = 31 - sum % 31;
    if (c18 == 31) {
        c18 = 0;
    }
    return c18 == codes.get(check);

}