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Credit Card Number Generator
import java.util.List;
import java.util.Stack;
import java.util.Vector;
/**
* See the license below. Obviously, this is not a Javascript credit card number
* generator. However, The following class is a port of a Javascript credit card
* number generator.
*
* @author robweber
*
*/
public class RandomCreditCardNumberGenerator {
/*
* Javascript credit card number generator Copyright (C) 2006-2012 Graham King
*
* This program 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 2 of the License, or (at your
* option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* www.darkcoding.net
*/
public static final String[] VISA_PREFIX_LIST = new String[] { "4539",
"4556", "4916", "4532", "4929", "40240071", "4485", "4716", "4" };
public static final String[] MASTERCARD_PREFIX_LIST = new String[] { "51",
"52", "53", "54", "55", "2221", "2222", "2223", "2224", "2225", "2226", "2227", "2228", "2229", "223", "224", "225", "226", "227", "228", "229", "23", "24", "25", "26", "270", "271", "2720" };
public static final String[] AMEX_PREFIX_LIST = new String[] { "34", "37" };
public static final String[] DISCOVER_PREFIX_LIST = new String[] { "6011" };
public static final String[] DINERS_PREFIX_LIST = new String[] { "300",
"301", "302", "303", "36", "38" };
public static final String[] ENROUTE_PREFIX_LIST = new String[] { "2014",
"2149" };
public static final String[] JCB_PREFIX_LIST = new String[] { "35" };
public static final String[] VOYAGER_PREFIX_LIST = new String[] { "8699" };
static String strrev(String str) {
if (str == null)
return "";
String revstr = "";
for (int i = str.length() - 1; i >= 0; i--) {
revstr += str.charAt(i);
}
return revstr;
}
/*
* 'prefix' is the start of the CC number as a string, any number of digits.
* 'length' is the length of the CC number to generate. Typically 13 or 16
*/
static String completed_number(String prefix, int length) {
String ccnumber = prefix;
// generate digits
while (ccnumber.length() < (length - 1)) {
ccnumber += new Double(Math.floor(Math.random() * 10)).intValue();
}
// reverse number and convert to int
String reversedCCnumberString = strrev(ccnumber);
List<Integer> reversedCCnumberList = new Vector<Integer>();
for (int i = 0; i < reversedCCnumberString.length(); i++) {
reversedCCnumberList.add(new Integer(String
.valueOf(reversedCCnumberString.charAt(i))));
}
// calculate sum
int sum = 0;
int pos = 0;
Integer[] reversedCCnumber = reversedCCnumberList
.toArray(new Integer[reversedCCnumberList.size()]);
while (pos < length - 1) {
int odd = reversedCCnumber[pos] * 2;
if (odd > 9) {
odd -= 9;
}
sum += odd;
if (pos != (length - 2)) {
sum += reversedCCnumber[pos + 1];
}
pos += 2;
}
// calculate check digit
int checkdigit = new Double(
((Math.floor(sum / 10) + 1) * 10 - sum) % 10).intValue();
ccnumber += checkdigit;
return ccnumber;
}
public static String[] credit_card_number(String[] prefixList, int length,
int howMany) {
Stack<String> result = new Stack<String>();
for (int i = 0; i < howMany; i++) {
int randomArrayIndex = (int) Math.floor(Math.random()
* prefixList.length);
String ccnumber = prefixList[randomArrayIndex];
result.push(completed_number(ccnumber, length));
}
return result.toArray(new String[result.size()]);
}
public static String[] generateMasterCardNumbers(int howMany) {
return credit_card_number(MASTERCARD_PREFIX_LIST, 16, howMany);
}
public static String generateMasterCardNumber() {
return credit_card_number(MASTERCARD_PREFIX_LIST, 16, 1)[0];
}
public static boolean isValidCreditCardNumber(String creditCardNumber) {
boolean isValid = false;
try {
String reversedNumber = new StringBuffer(creditCardNumber)
.reverse().toString();
int mod10Count = 0;
for (int i = 0; i < reversedNumber.length(); i++) {
int augend = Integer.parseInt(String.valueOf(reversedNumber
.charAt(i)));
if (((i + 1) % 2) == 0) {
String productString = String.valueOf(augend * 2);
augend = 0;
for (int j = 0; j < productString.length(); j++) {
augend += Integer.parseInt(String.valueOf(productString
.charAt(j)));
}
}
mod10Count += augend;
}
if ((mod10Count % 10) == 0) {
isValid = true;
}
} catch (NumberFormatException e) {
}
return isValid;
}
public static void main(String[] args) {
int howMany = 0;
try {
howMany = Integer.parseInt(args[0]);
} catch (Exception e) {
System.err
.println("Usage error. You need to supply a numeric argument (ex: 500000)");
}
String[] creditcardnumbers = generateMasterCardNumbers(howMany);
for (int i = 0; i < creditcardnumbers.length; i++) {
System.out.println(creditcardnumbers[i]
+ ":"
+ (isValidCreditCardNumber(creditcardnumbers[i]) ? "valid"
: "invalid"));
}
}
}
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