银行卡生成码

Question

这个程序用来创建一个随机的银行卡号码。卡号是使用帐户类型和客户端位置为前8位创建的，其余8位是完全随机的。我是这个网站的新手，但我相信这只是为了让代码评审来获得对代码的意见。如果我说错了，请告诉我，我可以把这个记下来。否则，随时给我反馈。谢谢!

import java.util.ArrayList;
import java.util.Scanner;

public class Main {

    private static ArrayList<String> storedCardNumbers = new ArrayList<String>();

    public static void main(String[] args) {

        menu();

    }

    //create menu for checking list of cards or creating a new card
    public static void menu(){
        //used to check if client wants to exit program
        boolean exit = false;

        System.out.println("___________________\n" +
                "Welcome to our bank!\n" + "Choose an option below: \n" +
                "1. Create new bank card.\n" +
                "2. Check existing cards.\n" +
                "3. Exit.");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();

        if(choice == 1) {
            createNewCard();
        } else if(choice == 2){
            System.out.println("-------------------------");
            System.out.println("There are " + storedCardNumbers.size() + " cards in the system");
            for (int i = 0; i < storedCardNumbers.size(); i++) {
                System.out.println(storedCardNumbers.get(i).toString());
            }
            System.out.println("-------------------------");
        } else if(choice == 3) {
            System.out.println("Thank you for coming in!");
            exit = true;
        } else {
                System.out.println("Incorrect choice.\n" +
                        "Please choose a valid option: ");
                menu();
            }

        if(exit == false) {
            System.out.println("Would you like to do anything else?");
            menu();
        } else {

        }
        }


    //create new bank card with user params
    public static String createNewCard() {
//        String accountType = setCardAccountType();
//        String location = setAccountLocation();
        String cardNumber = getCardNumber(setCardAccountType(),setAccountLocation());
        System.out.println("New card successfully created.\n" +
                "Your new bank card number is: \n" +
                cardNumber);
        storedCardNumbers.add(cardNumber);
        return cardNumber;
        }

        public static String setAccountLocation() {

            String location = "other";

            System.out.println("What is your location?\n" +
                    "1. US East\n" +
                    "2. US West\n" +
                    "3. Hawaii\n" +
                    "4. Alaska\n" +
                    "5. Other.");
            Scanner scanner = new Scanner(System.in);
            int choice = scanner.nextInt();

            if (choice == 1) {
                location.equalsIgnoreCase("useast");
            } else if (choice == 2) {
                location.equalsIgnoreCase("uswest");
            } else if (choice == 3) {
                location.equalsIgnoreCase("alaska");
            } else if (choice == 4) {
                location.equalsIgnoreCase("hawaii");
            } else if(choice == 5) {
                location.equalsIgnoreCase("other");
            }else {
                System.out.println("Entered invalid selection.\n" +
                        "Please enter valid selection.");
                setCardAccountType();
            }

            return location;
        }

        //set the card account type for the creatNewCard method to use
        public static String setCardAccountType() {

            String accountType = "other";

            System.out.println("Which type of account do you have?\n" +
                    "1. Checking.\n" +
                    "2. Savings.\n" +
                    "3. Credit.\n" +
                    "4. Other.\n" +
                    "Enter corresponding digit: ");
            Scanner scanner = new Scanner(System.in);
            int choice = scanner.nextInt();

            if (choice == 1) {
                accountType.equalsIgnoreCase("checking");
            } else if (choice == 2) {
                accountType.equalsIgnoreCase("savings");
            } else if (choice == 3) {
                accountType.equalsIgnoreCase("credit");
            } else if (choice == 4) {
                accountType.equalsIgnoreCase("other");
            } else {
                System.out.println("Entered invalid selection.\n" +
                        "Please enter valid selection.");
                setCardAccountType();
            }

            return accountType;
        }

    //create random number for card
    public static int getRandom(int min, int max) {
        return (int) (Math.random()*(max - min)) + min;
    }

    public static String getCardNumber(String accountType, String location) {
        //first set of four
        int accountKeySet;
        //second set of four
        int locationKeySet;
        //third set of four
        int lastEightFirst;
        //fourth set of four
        int lastEightSecond;

        //assign a value to each account type
        if(accountType.equalsIgnoreCase("checking")) {
            accountKeySet = 4400;
        } else if(accountType.equalsIgnoreCase("savings")) {
            accountKeySet = 4300;
        } else if(accountType.equalsIgnoreCase("credit")) {
            accountKeySet = 4200;
        } else {
            accountKeySet = 4000;
        }


        //Assign a value to each location of client
        if(location.equalsIgnoreCase("useast")) {
            locationKeySet = 1011;
        } else if(location.equalsIgnoreCase("uswest")) {
            locationKeySet = 2011;
        } else if (location.equalsIgnoreCase("Alaska")) {
            locationKeySet = 3011;
        } else if (location.equalsIgnoreCase("hawaii")) {
            locationKeySet = 4011;
        } else {
            locationKeySet = 1022;
        }

        //create a randomized number for last of card number
        lastEightFirst = getRandom(1000,9999);
        lastEightSecond = getRandom(1000,9999);

        //construct card number
        StringBuilder key = new StringBuilder();
        key.append(accountKeySet);
        key.append(" ");
        key.append(locationKeySet);
        key.append(" ");
        key.append(lastEightFirst);
        key.append(" ");
        key.append(lastEightSecond);
        return key.toString();
    }
}

Answer 1

嗨，尼古拉斯，欢迎来到代码评审。

我在您的代码中注意到了一些事情：

• 压痕不一致。menu的结束括号不是它应该在的位置。整个setAccountLocation方法是位于最右边的一个选项卡。如果您要修复这个问题，代码的可读性会更好。在Eclipse中，您可以按Ctrl + Shift +F键自动修复缩进
• 根据我的经验，开放多重Scanners会产生问题。我建议在主方法中只打开一个Scanner，然后在其他方法中使用它。
• 在setAccountLocation中，可以多次使用location.equalsIgnoreCase。这没什么用。我认为您希望将字符串分配给location变量，这样您就可以简单地编写location = "useast";等。
• setAccountType中的帐户类型也是一样的。
• accountType和location从不由用户输入，因此您不需要equalsIgnoreCase，但您可以简单地使用equals。
• 我建议不要将accountType和location作为字符串传递，而是为它们创建枚举。
• 在menu中，您有一行System.out.println(storedCardNumbers.get(i).toString());。您不需要toString，因为它已经是一个字符串了。此外，println方法隐式调用您传递的每个对象的toString方法。

Answer 2

这个程序用来创建一个随机的银行卡号码。卡号是使用帐户类型和客户端位置为前8位创建的，其余8位是完全随机的。

这不是对编码本身的批评，而是对需求收集的批评。银行卡不允许使用完全随机的最后八个字符。因为第16个字符是校验和。所以你应该生成七个随机数字，而不是八个。然后计算前十五的最后一个数字。