java信用卡验证器

Question

I need to do a Credit card number validation.

When I googled this I found the org.apache.commons.validator.CreditCardValidator . But seems like it is not working correctly. When I pass a non-digit character also it porvides true.

Code for Apache CreditCardValidator :

String ccNumber = "378282246310005";
CreditCardValidator creditCardValidator = new CreditCardValidator();
if(!creditCardValidator.isValid(ccNumber)) throw new Exception("Credit Card Number is not a valid one!");

Then, I wrote following methods to validate credit card numbers based on the card type and the card number (using the luhn's algorithm).

CardType validator (null if an invalid card type)

public String getCCType(String ccNumber){

        String visaRegex        = "^4[0-9]{12}(?:[0-9]{3})?$";
        String masterRegex      = "^5[1-5][0-9]{14}$";
        String amexRegex        = "^3[47][0-9]{13}$";
        String dinersClubrRegex = "^3(?:0[0-5]|[68][0-9])[0-9]{11}$";
        String discoverRegex    = "^6(?:011|5[0-9]{2})[0-9]{12}$";
        String jcbRegex         = "^(?:2131|1800|35\\d{3})\\d{11}$";
        String commonRegex      = "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\\d{3})\\d{11})$";

        try {
            ccNumber = ccNumber.replaceAll("\\D", "");
            return (ccNumber.matches(visaRegex) ? "VISA" : ccNumber.matches(masterRegex) ? "MASTER" :ccNumber.matches(amexRegex) ? "AMEX" :ccNumber.matches(dinersClubrRegex) ? "DINER" :ccNumber.matches(discoverRegex) ? "DISCOVER"  :ccNumber.matches(jcbRegex) ? "JCB":null);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

CardNumber validator using Luhn's algorithem.

public boolean isValidCardNumber(String ccNumber){

        try {
            ccNumber = ccNumber.replaceAll("\\D", "");
            char[]      ccNumberArry    = ccNumber.toCharArray();

            int         checkSum        = 0;
            for(int i = ccNumberArry.length - 1; i >= 0; i--){

                char            ccDigit     = ccNumberArry[i];

                if((ccNumberArry.length - i) % 2 == 0){
                    int doubleddDigit = Character.getNumericValue(ccDigit) * 2;
                    checkSum    += (doubleddDigit % 9 == 0 && doubleddDigit != 0) ? 9 : doubleddDigit % 9;

                }else{
                    checkSum    += Character.getNumericValue(ccDigit);
                }

            }

            return (checkSum != 0 && checkSum % 10 == 0);

        } catch (Exception e) {

            e.printStackTrace();

        }

        return false;
    }

I want to know,

1. Is there any other thrid party class to validate the credit cards other than the org.apache one?
2. Is there any issue with the my code? (I tested it for several times. So far so good. I just want to know if you could spot something that I didn't.)

References : How do you detect Credit card type based on number?

Answer 1

I did this a long time ago, Sorry Code is in C. Easily Convertible. Hope this will help you.

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

int CardNoChecker(unsigned long long int Number)
{
        int dijts=0;
        int Ans=0;
        {
            unsigned long long int k=1;
            while(Number%k!=Number)
            {
                    dijts=dijts+1;
                    k=k*10;
            }
        }
    {
        int i=1;
        int Product=0;
        int Sum=0;
        for(i=dijts;i>=1;i--)
        {
                if(i%2==0)
                {
                    if((Number%10)*2<10)
                    Product = Product + (  Number % 10  ) * 2 ;
                    else
                    {
                        int No=(Number%10)*2;
                        Product = Product + No/10;
                        Product = Product + No%10;
                    }
                }
                else
                {
                    Sum = Sum + (  Number  % 10     ) ;
                }
                Number=Number /10;
        }
        Ans = Sum + Product ;
    }
    if(Ans%10==0)
    return (1);
    else
    return (0);
}

int main()
{
    unsigned long long int CardNO;
    int valid=0;
    while(!valid)
    {
        int CnV=0;
        int VC=0;
        int AE=0;
        int MC=0;
        printf("Enter Card NO : ");
        scanf("%llu",&CardNO);
        if(CardNO/1000000000000==4 || CardNO/1000000000000000==4)
        {
            VC=1;
        }
        else if(CardNO/10000000000000==34 ||CardNO/10000000000000==37)
        {
            AE=1;
        }
        else if(CardNO/100000000000000==51 || CardNO/100000000000000==52 || CardNO/100000000000000==53 || CardNO/100000000000000==54 || CardNO/100000000000000==55)
        {
            MC=1;
        }
        CnV=CardNoChecker(CardNO);
        if(CnV && MC )
         printf("This is a Valid Master Card\n\n");
         else if(CnV && VC )
         printf("This is a Valid Visa Card\n\n");
         else if(CnV && AE )
         printf("This is a Valid American Express Card\n\n");
         else
        printf("Card is Not Valid'\n\n");
    }

    return (0);
}

Answer 2

Have a look to Luhn algorithm https://en.wikipedia.org/wiki/Luhn_algorithm

 public static void main(String[] args) {
    boolean isValid = checkCC("4561 2612 1234 5467");
    System.out.println(isValid);
}

private static boolean checkCC(String input)  {
    String purportedCC = input.replaceAll(" ", "");
    int sum = 0;

    for (int i = 0; i < purportedCC.length(); i++) {
        int cardNum = Integer.parseInt(
                Character.toString(purportedCC.charAt(i)));

        if ((purportedCC.length() - i) % 2 == 0) {
            cardNum = cardNum * 2;

            if (cardNum > 9) {
                cardNum = cardNum - 9;
            }
        }

        sum += cardNum;
    }
    return sum % 10 == 0;
}

Answer 3

You can find custom implantation of credit card validator here which is doing both credit card number validation plus credit card type detection,

http://www.esupu.com/credit-card-validator-java/