信用卡的第一个数字可以用来大致了解供应商:

签证:49、44或47 Visa电子:42、45、48、49 万事达卡:51 美国运通:34 就餐者:30、36、38 JCB: 35

我用jQuery的解决方案:

function detectCreditCardType() {
    var type = new Array;
    type[1] = '^4[0-9]{12}(?:[0-9]{3})?$';      // visa
    type[2] = '^5[1-5][0-9]{14}$';              // mastercard
    type[3] = '^6(?:011|5[0-9]{2})[0-9]{12}$';  // discover
    type[4] = '^3[47][0-9]{13}$';               // amex

    var ccnum = $('.creditcard').val().replace(/[^\d.]/g, '');
    var returntype = 0;

    $.each(type, function(idx, re) {
        var regex = new RegExp(re);
        if(regex.test(ccnum) && idx>0) {
            returntype = idx;
        }
    });

    return returntype;
}

如果返回0，则未检测到信用卡类型。

“creditcard”类应该添加到creditcard输入字段中。

不要试图检测信用卡类型作为处理支付的一部分。您正在冒着拒绝有效事务的风险。

如果您需要向您的支付处理器提供信息(例如，PayPal信用卡对象需要命名卡类型)，那么从可用的最少信息中猜测它，例如。

$credit_card['pan'] = preg_replace('/[^0-9]/', '', $credit_card['pan']);
$inn = (int) mb_substr($credit_card['pan'], 0, 2);

// @see http://en.wikipedia.org/wiki/List_of_Bank_Identification_Numbers#Overview
if ($inn >= 40 && $inn <= 49) {
    $type = 'visa';
} else if ($inn >= 51 && $inn <= 55) {
    $type = 'mastercard';
} else if ($inn >= 60 && $inn <= 65) {
    $type = 'discover';
} else if ($inn >= 34 && $inn <= 37) {
    $type = 'amex';
} else {
    throw new \UnexpectedValueException('Unsupported card type.');
}

这个实现(只使用前两位数字)足以识别所有主要的(在PayPal的情况下是所有受支持的)卡片方案。实际上，您可能希望完全跳过异常，并默认使用最流行的卡片类型。让支付网关/处理器告诉您在响应您的请求时是否存在验证错误。

现实情况是，你的支付网关并不关心你提供的价值。

卡号的前六位数字(包括初始信息信息) 数字)被称为发行者识别号码(IIN)。这些 识别向该卡发行该卡的发卡机构 持有人。其余的数字由发卡机构分配。的 卡号的长度是它的位数。许多发卡机构打印 他们卡上的整个IIN和账号。

基于以上事实，我想保留一段JAVA代码来识别卡片品牌。

样卡类型

public static final String AMERICAN_EXPRESS = "American Express";
public static final String DISCOVER = "Discover";
public static final String JCB = "JCB";
public static final String DINERS_CLUB = "Diners Club";
public static final String VISA = "Visa";
public static final String MASTERCARD = "MasterCard";
public static final String UNKNOWN = "Unknown";

卡前缀

// Based on http://en.wikipedia.org/wiki/Bank_card_number#Issuer_identification_number_.28IIN.29
public static final String[] PREFIXES_AMERICAN_EXPRESS = {"34", "37"};
public static final String[] PREFIXES_DISCOVER = {"60", "62", "64", "65"};
public static final String[] PREFIXES_JCB = {"35"};
public static final String[] PREFIXES_DINERS_CLUB = {"300", "301", "302", "303", "304", "305", "309", "36", "38", "39"};
public static final String[] PREFIXES_VISA = {"4"};
public static final String[] PREFIXES_MASTERCARD = {
        "2221", "2222", "2223", "2224", "2225", "2226", "2227", "2228", "2229",
        "223", "224", "225", "226", "227", "228", "229",
        "23", "24", "25", "26",
        "270", "271", "2720",
        "50", "51", "52", "53", "54", "55"
    };

检查输入的数字是否有任何给定的前缀。

public String getBrand(String number) {

String evaluatedType;
if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_AMERICAN_EXPRESS)) {
    evaluatedType = AMERICAN_EXPRESS;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_DISCOVER)) {
    evaluatedType = DISCOVER;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_JCB)) {
    evaluatedType = JCB;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_DINERS_CLUB)) {
    evaluatedType = DINERS_CLUB;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_VISA)) {
    evaluatedType = VISA;
} else if (StripeTextUtils.hasAnyPrefix(number, PREFIXES_MASTERCARD)) {
    evaluatedType = MASTERCARD;
} else {
    evaluatedType = UNKNOWN;
}
    return evaluatedType;
}

最后，效用方法

/**
  * Check to see if the input number has any of the given prefixes.
  *
  * @param number the number to test
  * @param prefixes the prefixes to test against
  * @return {@code true} if number begins with any of the input prefixes
*/

public static boolean hasAnyPrefix(String number, String... prefixes) {
  if (number == null) {
       return false;
  }
   for (String prefix : prefixes) {
       if (number.startsWith(prefix)) {
       return true;
    }
  }
     return false;
}

参考

条纹卡生成器

follow Luhn’s algorithm

 private  boolean validateCreditCardNumber(String str) {

        int[] ints = new int[str.length()];
        for (int i = 0; i < str.length(); i++) {
            ints[i] = Integer.parseInt(str.substring(i, i + 1));
        }
        for (int i = ints.length - 2; i >= 0; i = i - 2) {
            int j = ints[i];
            j = j * 2;
            if (j > 9) {
                j = j % 10 + 1;
            }
            ints[i] = j;
        }
        int sum = 0;
        for (int i = 0; i < ints.length; i++) {
            sum += ints[i];
        }
        if (sum % 10 == 0) {
           return true;
        } else {
            return false;
        }


    }

then call this method

Edittext mCreditCardNumberEt;

 mCreditCardNumberEt.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

             int cardcount=   s.toString().length();
                 if(cardcount>=16) {
                    boolean cardnumbervalid=   validateCreditCardNumber(s.toString());
                    if(cardnumbervalid) {
                        cardvalidtesting.setText("Valid Card");
                        cardvalidtesting.setTextColor(ContextCompat.getColor(context,R.color.green));
                    }
                    else {
                        cardvalidtesting.setText("Invalid Card");
                        cardvalidtesting.setTextColor(ContextCompat.getColor(context,R.color.red));
                    }
                }
               else if(cardcount>0 &&cardcount<16) {
                     cardvalidtesting.setText("Invalid Card");
                     cardvalidtesting.setTextColor(ContextCompat.getColor(context,R.color.red));
                }

                else {
                    cardvalidtesting.setText("");

                }


                }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });

压缩javascript版本

    var getCardType = function (number) {
        var cards = {
            visa: /^4[0-9]{12}(?:[0-9]{3})?$/,
            mastercard: /^5[1-5][0-9]{14}$/,
            amex: /^3[47][0-9]{13}$/,
            diners: /^3(?:0[0-5]|[68][0-9])[0-9]{11}$/,
            discover: /^6(?:011|5[0-9]{2})[0-9]{12}$/,
            jcb: /^(?:2131|1800|35\d{3})\d{11}$/
        };
        for (var card in cards) {
            if (cards[card].test(number)) {
                return card;
            }
        }
    };