How to check IBAN validation?

How can I validate IBAN (International Bank Account Number) in java to use in Android Apps?

The International Bank Account Number is an internationally agreed system of identifying bank accounts across national borders to facilitate the communication and processing of cross border transactions with a reduced risk of transcription errors.

private boolean isIbanValid(String iban) {

    int IBAN_MIN_SIZE = 15;
    int IBAN_MAX_SIZE = 34;
    long IBAN_MAX = 999999999;
    long IBAN_MODULUS = 97;

    String trimmed = iban.trim();

    if (trimmed.length() < IBAN_MIN_SIZE || trimmed.length() > IBAN_MAX_SIZE) {
        return false;
    }

    String reformat = trimmed.substring(4) + trimmed.substring(0, 4);
    long total = 0;

    for (int i = 0; i < reformat.length(); i++) {

        int charValue = Character.getNumericValue(reformat.charAt(i));

        if (charValue < 0 || charValue > 35) {
            return false;
        }

        total = (charValue > 9 ? total * 100 : total * 10) + charValue;

        if (total > IBAN_MAX) {
            total = (total % IBAN_MODULUS);
        }
    }

    return (total % IBAN_MODULUS) == 1;
}