java上机实验五bank

Java上机实验五：银行账户管理系统

本实验要求使用Java面向对象的编程思想，实现一个简单的银行账户管理系统。在该系统中，每个账户都有一个账户号、账户余额、账户利率等信息，可以进行存款、取款、查询余额、计算利息、修改利率等基本操作。

实验要求：

1. 编写一个Account类，该类包含以下成员变量：

- 账户号（id）
- 账户余额（balance）
- 年利率（annualInterestRate）

2. Account类还包含以下方法：

- 无参构造方法
- 带参构造方法，可以为所有成员变量赋值
- 存款（deposit）方法，将指定金额加到账户余额中
- 取款（withdraw）方法，从账户余额中减去指定金额
- 查询余额（getBalance）方法
- 计算利息（getMonthlyInterest）方法，返回当前账户月利息
- 修改年利率（setAnnualInterestRate）方法

3. 编写一个测试类，测试Account类中的各个方法是否正确。

4. 扩展Account类，实现两个子类：

- CheckingAccount类，该类继承Account类，代表一个支票账户，每次取款都会收取一定手续费。
- SavingsAccount类，该类继承Account类，代表一个储蓄账户，每年会发生一次利息结算。

5. 编写一个Bank类，该类用于管理多个账户，实现以下方法：

- addAccount方法，添加一个账户
- removeAccount方法，删除一个账户
- getTotalBalance方法，返回所有账户的总余额
- getAverageBalance方法，返回所有账户的平均余额
- getNumberOfAccounts方法，返回账户的总数

6. 编写一个测试类，测试Bank类中的各个方法是否正确。

提示：

- 可以使用ArrayList来存储所有的账户。
- 在子类中可以使用super关键字来调用父类的构造方法或方法。
- 在SavingsAccount类中，可以使用Calendar类来获取当前的日期和时间，然后判断是否需要进行利息结算。

参考代码：（仅供参考，学生应自主完成实验）

Account类：

public class Account {
    private int id;
    private double balance;
    private double annualInterestRate;

    public Account() {
    }

    public Account(int id, double balance, double annualInterestRate) {
        this.id = id;
        this.balance = balance;
        this.annualInterestRate = annualInterestRate;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public double getBalance() {
        return balance;
    }

    public void setBalance(double balance) {
        this.balance = balance;
    }

    public double getAnnualInterestRate() {
        return annualInterestRate;
    }

    public void setAnnualInterestRate(double annualInterestRate) {
        this.annualInterestRate = annualInterestRate;
    }

    public void deposit(double amount) {
        balance += amount;
    }

    public void withdraw(double amount) {
        balance -= amount;
    }

    public double getMonthlyInterest() {
        return balance * annualInterestRate / 12;
    }
}

CheckingAccount类：

public class CheckingAccount extends Account {
    private double fee;

    public CheckingAccount() {
    }

    public CheckingAccount(int id, double balance, double annualInterestRate, double fee) {
        super(id, balance, annualInterestRate);
        this.fee = fee;
    }

    public double getFee() {
        return fee;
    }

    public void setFee(double fee) {
        this.fee = fee;
    }

    @Override
    public void withdraw(double amount) {
        super.withdraw(amount);
        balance -= fee;
    }
}

SavingsAccount类：

import java.util.Calendar;

public class SavingsAccount extends Account {
    private Calendar lastInterestDate;

    public SavingsAccount() {
    }

    public SavingsAccount(int id, double balance, double annualInterestRate) {
        super(id, balance, annualInterestRate);
        lastInterestDate = Calendar.getInstance();
    }

    public void addInterest() {
        Calendar now = Calendar.getInstance();
        if (now.get(Calendar.MONTH) != lastInterestDate.get(Calendar.MONTH)) {
            double interest = getMonthlyInterest() * 12;
            balance += interest;
            lastInterestDate = now;
        }
    }
}

Bank类：

import java.util.ArrayList;

public class Bank {
    private ArrayList<Account> accounts;

    public Bank() {
        accounts = new ArrayList<>();
    }

    public void addAccount(Account account) {
        accounts.add(account);
    }

    public void removeAccount(Account account) {
        accounts.remove(account);
    }

    public double getTotalBalance() {
        double total = 0;
        for (Account account : accounts) {
            total += account.getBalance();
        }
        return total;
    }

    public double getAverageBalance() {
        double total = getTotalBalance();
        return total / accounts.size();
    }

    public int getNumberOfAccounts() {
        return accounts.size();
    }
}

测试类：

public class Test {
    public static void main(String[] args) {
        Account account1 = new Account(1, 1000, 0.01);
        account1.deposit(100);
        account1.withdraw(200);
        System.out.println("Account 1 balance: " + account1.getBalance());
        System.out.println("Account 1 monthly interest: " + account1.getMonthlyInterest());

        CheckingAccount account2 = new CheckingAccount(2, 1000, 0.01, 10);
        account2.withdraw(200);
        System.out.println("Account 2 balance: " + account2.getBalance());
        System.out.println("Account 2 monthly interest: " + account2.getMonthlyInterest());

        SavingsAccount account3 = new SavingsAccount(3, 1000, 0.01);
        account3.addInterest();
        System.out.println("Account 3 balance: " + account3.getBalance());
        System.out.println("Account 3 monthly interest: " + account3.getMonthlyInterest());

        Bank bank = new Bank();
        bank.addAccount(account1);
        bank.addAccount(account2);
        bank.addAccount(account3);
        System.out.println("Total balance: " + bank.getTotalBalance());
        System.out.println("Average balance: " + bank.getAverageBalance());
        System.out.println("Number of accounts: " + bank.getNumberOfAccounts());
    }
}