用Java设计一个ATM取款机取款系统，具备注册，登录，查询，存款和取款基本功能

在Java中设计一个简单的ATM取款机模拟系统，我们可以创建几个类来实现这个功能：

1. **Account** 类：表示用户的账户，包含账户号、余额等属性。

public class Account {
    private String accountNumber;
    private double balance;

    // 构造函数，getters和setters
    public Account(String accountNumber, double initialBalance) {
        this.accountNumber = accountNumber;
        this.balance = initialBalance;
    }

    // 取款方法
    public boolean withdraw(double amount) {
        if (amount <= balance) {
            balance -= amount;
            return true;
        } else {
            System.out.println("Insufficient balance.");
            return false;
        }
    }

    // 其他方法...
}

2. **User** 类：用户有密码和关联的账户信息。

public class User {
    private String username;
    private String password;
    private Account account;

    // 构造函数，getters和setters
    public User(String username, String password, Account account) {
        this.username = username;
        this.password = password;
        this.account = account;
    }

    // 登录方法
    public boolean login(String inputPassword) {
        if (inputPassword.equals(password)) {
            return true;
        } else {
            return false;
        }
    }

    // 其他方法...
}

3. **ATMMachine** 类：用于处理 ATM 的操作。

public class ATMMachine {
    private Map<String, User> users;

    public ATMMachine() {
        users = new HashMap<>();
    }

    // 注册方法
    public void register(String username, String password, Account account) {
        users.put(username, new User(username, password, account));
    }

    // 查询余额方法
    public void queryBalance(String username) {
        User user = users.get(username);
        if (user != null && user.login(username)) {
            System.out.println("Your current balance is: " + user.getAccount().getBalance());
        } else {
            System.out.println("Invalid username or incorrect password.");
        }
    }

    // 存款和取款方法
    public void deposit(String username, double amount) {
        User user = users.get(username);
        if (user != null && user.login(username)) {
            user.getAccount().deposit(amount);
            System.out.println("Deposit successful. New balance: " + user.getAccount().getBalance());
        }
    }

    // 取款方法
    public void withdraw(String username, double amount) {
        User user = users.get(username);
        if (user != null && user.login(username)) {
            boolean result = user.getAccount().withdraw(amount);
            if (result) {
                System.out.println("Withdrawal successful. New balance: " + user.getAccount().getBalance());
            } else {
                System.out.println("Withdrawal failed.");
            }
        } else {
            System.out.println("Invalid username or incorrect password.");
        }
    }
}