// Chromis POS - The New Face of Open Source POS
// Copyright (c) (c) 2015-2016
// http://www.chromis.co.uk
//
// This file is part of Chromis POS
//
// Chromis POS is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Chromis POS is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Chromis POS. If not, see <http://www.gnu.org/licenses/>.
package uk.chromis.pos.util;
/**
*
* @author Mikel Irurita
*/
public class LuhnAlgorithm {
/** Creates a new instance of LuhnAlgorithm */
private LuhnAlgorithm() {
}
/**
*
* @param cardNumber
* @return
*/
public static boolean checkCC(String cardNumber){
int sum = 0;
int flip = 0;
if ( !StringUtils.isNumber(cardNumber) ){
return false;
}
for (int i = cardNumber.length() -1; i >= 0; i--) {
int k = Character.digit(cardNumber.charAt(i), 10);
flip ++;
if ( flip % 2 == 0 ) {
k *= 2;
if (k > 9) {
k -= 9;
}
}
sum += k;
}
return (sum % 10 == 0);
}
// Resolution of AMEX card issue
// Mikel Iurata, Openbravo Thu Sep 16
// public static void main(String[] args) {
// // Testing sample numbers
//
// System.out.println(LuhnAlgorithm.checkCC("4111111111111111")); // Visa
// System.out.println(LuhnAlgorithm.checkCC("5500000000000004")); // Master card
// System.out.println(LuhnAlgorithm.checkCC("340000000000009")); // AMEX
// System.out.println(LuhnAlgorithm.checkCC("30000000000004")); // Diners
// System.out.println(LuhnAlgorithm.checkCC("30000000000004")); // Carte blanche
// System.out.println(LuhnAlgorithm.checkCC("6011000000000004")); // Discover
// System.out.println(LuhnAlgorithm.checkCC("201400000000009")); // EnRoute
}