Question

我有一项任务是创建一个小银行计划，保留两个帐户，定期和节省。然而，当我即将完成一个粗略的版本时，我读到了提示，我想要使用我们在生病那天学到的东西，例外。

我不清楚如何使用异常或者我应该创建自己的异常类。我想要一个例外，这样在程序中的任何一点如果输入以'q'或'Q'开头的东西，程序就会退出并结束。另一项规定是如果节省的费用低于25美元以冻结帐户。我认为异常对于该功能来说是理想的。

public abstract class BankAccount {

    int balance;
    int deposits;
    int withdrawals;
    int annualInterestRate;
    int charges;

    public void _BankAccount(int newBalance, int newInterest) {
        balance = newBalance;
        annualInterestRate = newInterest;
    }

    public void Deposit(int newDeposit) {
        balance = balance + newDeposit;
        deposits++;
    }

    public void Withdraw(int newWithdraw) {
        balance = balance - newWithdraw;
        withdrawals++;
    }

    public void calcInterest() {
        int monthlyInterestRate = (annualInterestRate / 12);
        int monthlyInterest = balance * monthlyInterestRate;
        balance = balance + monthlyInterest;
    }

    public void monthlyProcess() {
        balance = balance - charges;
        calcInterest();
        deposits = 0;
        withdrawals = 0;
    }
}

public class SavingsAccount extends BankAccount {

    boolean status;

    public void savingWithdraw(int newWithdraw) {
        if (balance < 25) {
            System.out.println("Error – Not enough funds.");
        } else {
            Withdraw(newWithdraw);
        }
    }

    public void savingDeposit(int newDeposit) {
        if (balance < 25) {
            Deposit(newDeposit);
            System.out.println("Savings account is now active.");
        } else {
            Deposit(newDeposit);
        }
    }

    public void savingMonthlyProcess() {
        if (withdrawals > 4) {
            charges = ((withdrawals - 4) * 1);
            balance = balance - ((withdrawals - 4) * 1);
            if (balance < 25) {
                System.out.println("Savings account is now inactive.");
            }
        }
    }
}

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    String choice;
    int num = 0;
    boolean quit = false;
    do {
        System.out.println("Which account would you like to access, regular or savings?:");
        choice = in.nextLine();
        if (choice.equals("regular")) {
            num = 0;
        }
        if (choice.equals("savings")) {
            num = 1;
        }
        switch (num) {
            case 0:
                System.out.println("What action do you wish to perform \n(Withdraw, deposit, monthly processing)?:");
                choice = in.nextLine();
                if (choice.equals("withdraw")) {
                    num = 0;
                }
                if (choice.equals("deposit")) {
                    num = 1;
                }
                if (choice.equals("monthly processing")) {
                    num = 2;
                }
                switch (num) {
                    case 0:
                        System.out.println("Enter amount to withdraw:");
                        Withdraw(in.nextInt());
                    case 1:
                        System.out.println("Enter amount to withdraw:");
                        Deposit(in.nextInt());
                    case 2:
                        MonthlyProcess();
                }
            case 1:
                System.out.println("What action do you wish to perform \n(Withdraw, deposit, monthly processing)?:");
                choice = in.nextLine();
                if (choice.equals("withdraw")) {
                    num = 0;
                }
                if (choice.equals("deposit")) {
                    num = 1;
                }
                if (choice.equals("monthly processing")) {
                    num = 2;
                }
                switch (num) {
                    case 0:
                        System.out.println("Enter amount to withdraw:");
                        savingsWithdraw(in.nextInt());
                    case 1:
                        System.out.println("Enter amount to withdraw:");
                        savingsDeposit(in.nextInt());
                    case 2:
                        savingMonthlyProcess();
                }

        }
    }


}

}

Answer 1

异常用于处理不需要的情况。在您的情况下，您可以使用内置的异常类来处理大多数运行时异常，但使用自定义消息。

另一项规定是如果节省的费用低于25美元以冻结账户。

对于上述情况，您可以很好地创建一个新的异常类，并使用用户定义的错误消息处理此异常。

您可以在Exception handling in java上阅读更多信息。

在atm项目中实现异常

1 个答案: