在 java 中使用枚举检测卡类型时遇到问题

Question

我正在开发一个接受付款的 Android 应用程序。在这里，我在检测卡类型时遇到问题。在这里，我在 CardType.Java Enum return 中遇到一个问题 visa 它无法找到任何其他 卡片类型。我正在输入 600206 和我的 class return visa 而不是 MAESTRO哪里不对请帮帮我。

CardType.Java

public enum CardType {

VISA("4"),
MCRD("5"),
MAESTRO("67", "56", "502260", "504433",
        "504434", "504435", "504437", "504645", "504681",
        "504753", "504775", "504809", "504817", "504834",
        "504848", "504884", "504973", "504993", "508125",
        "508126", "508159", "508192", "508227", "600206",
        "603123", "603741", "603845", "622018"),
DINERCLUB("30", "36", "38", "39"),
JCB("35"),
AMEX("34", "37"),
DISCOVER("60", "62", "64", "65"),
UNKNOWN("0");

private final String[] pattern;

private CardType(String... pattern) {

    System.out.println("pattern== "+pattern.toString());
    this.pattern = pattern;
}




public static CardType typeOf(String card) {

    System.out.println("card== "+card);
    for (CardType type : values()) {

        System.out.println("type== "+type);
            return type;         
    }
   return null;
}

public static String getScheme(CardType cardType) {
    System.out.println("getScheme");
    switch (cardType) {
    case VISA:
        return "VISA";
    case MCRD:
        return "MCRD";
    case MAESTRO:
        return "MAESTRO";
    case DINERCLUB:
        return "DINERCLUB";
    case JCB:
        return "JCB";
    case AMEX:
        return "AMEX";
    case DISCOVER:
        return "DISCOVER";
    default:
        return "UNKNOWN";
    }
}
}

Answer 1

而不是

return type;

这总是 return 第一个枚举常量 (VISA)，do

if (Stream.of(pattern).anyMatch((p) -> card.startsWith(p))) {
    return type;
}

(Java 8) StartsWith 假定。

Java 7:

for (String p : pattern) { 
    if (card.startsWith(p)) {
        return type;
    }
}

Answer 2

您的 typeOf 方法 returns 枚举的第一个元素是 VISA，将其替换为

public static CardType typeOf(String card) {
    for (CardType type : values()) {
        for(String numbers : type.pattern) {
            if(numbers.equals(card)) {
                return type;
            }
        }
    }
    throw new IllegalArgumentException("Type for card pattern " + card + " was not found.");
}

在 java 中使用枚举检测卡类型时遇到问题

Faccing issue in detecting cardType using enum in java

java

regex

enums

android