java/w7/BankWithdrawalTest.java

public class BankWithdrawalTest {

    static class InsufficientFundsException extends Exception {
        private double balance;

        public InsufficientFundsException(double balance) {
            super("余额不足，当前余额：" + balance + " 元");
            this.balance = balance;
        }

        public double getBalance() {
            return balance;
        }
    }

    static class Account {
        private double balance;

        public Account(double initialBalance) {
            this.balance = initialBalance;
        }

        public void withdraw(double amount) throws InsufficientFundsException {
            if (amount <= 0) {
                throw new IllegalArgumentException("取款金额必须大于0");
            }
            if (amount > balance) {
                throw new InsufficientFundsException(balance);
            }
            balance -= amount;
            System.out.println("取款成功！取出：" + amount + " 元，剩余余额：" + balance + " 元");
        }

        public double getBalance() {
            return balance;
        }
    }

    public static void main(String[] args) {
        Account myAccount = new Account(1000.0);

        System.out.println("--- 测试1：正常取款 ---");
        try {
            myAccount.withdraw(300);
        } catch (InsufficientFundsException e) {
            System.out.println("错误：" + e.getMessage());
        }

        System.out.println("\n--- 测试2：余额不足取款 ---");
        try {
            myAccount.withdraw(800);
        } catch (InsufficientFundsException e) {
            System.out.println("取款失败：" + e.getMessage());
            System.out.println("提示：请检查取款金额，当前账户余额为 " + e.getBalance() + " 元");
        }

        System.out.println("\n--- 测试3：非法金额取款 ---");
        try {
            myAccount.withdraw(-50);
        } catch (IllegalArgumentException e) {
            System.out.println("错误：" + e.getMessage());
        } catch (InsufficientFundsException e) {
            System.out.println("取款失败：" + e.getMessage());
        }
    }
}