com.jidesoft.field.creditcard
Class CreditCardUtils

java.lang.Object
  com.jidesoft.field.creditcard.CreditCardUtils

public class CreditCardUtils
extends Object

Constructor Summary

CreditCardUtils()

Method Summary

static boolean

isValidNumber(String number) Checks whether a string of digits is a valid credit card number according to the Luhn algorithm.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CreditCardUtils

public CreditCardUtils()

Method Detail

isValidNumber

public static boolean isValidNumber(String number)

Checks whether a string of digits is a valid credit card number according to the Luhn algorithm.

1. Starting with the second to last digit and moving left, double the value of all the alternating digits. For any digits that thus become 10 or more, add their digits together. For example, 1111 becomes 2121, while 8763 becomes 7733 (from (1+6)7(1+2)3).

2. Add all these digits together. For example, 1111 becomes 2121, then 2+1+2+1 is 6; while 8763 becomes 7733, then 7+7+3+3 is 20.

3. If the total ends in 0 (put another way, if the total modulus 10 is 0), then the number is valid according to the Luhn formula, else it is not valid. So, 1111 is not valid (as shown above, it comes out to 6), while 8763 is valid (as shown above, it comes out to 20).

Parameters:

number - the credit card number to validate.

Returns:

true if the number is valid according to Lhun algorithm , false otherwise.