// uniCenta oPOS - Touch Friendly Point Of Sale // Copyright (c) 2009-2013 uniCenta // http://www.unicenta.net/unicentaopos // // This file is part of uniCenta oPOS // // uniCenta oPOS 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. // // uniCenta oPOS 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 uniCenta oPOS. If not, see <http://www.gnu.org/licenses/>. package com.openbravo.pos.util; /** * * @author Mikel Irurita */ public class LuhnAlgorithm { /** Creates a new instance of LuhnAlgorithm */ private LuhnAlgorithm() { } 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 // Jack Gerrard, uniCenta Fri Sep 17 // 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 }