public class BankAccount {
    // private 成员变量（封装：私有化属性）
    private String accountNumber;
    private String ownerName;
    private double balance;

    // 构造方法：初始化账户
    public BankAccount(String accountNumber, String ownerName) {
        this.accountNumber = accountNumber;
        this.ownerName = ownerName;
        this.balance = 0.0;
    }

    // getter 和 setter 方法（封装：提供公共访问接口）
    public String getAccountNumber() {
        return accountNumber;
    }

    public String getOwnerName() {
        return ownerName;
    }

    public void setOwnerName(String ownerName) {
        this.ownerName = ownerName;
    }

    public double getBalance() {
        return balance;
    }

    // 业务方法：存款
    public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
            System.out.println("存款成功，当前余额：" + balance);
        } else {
            System.out.println("存款金额必须大于0");
        }
    }

    // 业务方法：取款
    public void withdraw(double amount) {
        if (amount > 0 && amount <= balance) {
            balance -= amount;
            System.out.println("取款成功，当前余额：" + balance);
        } else {
            System.out.println("余额不足或金额无效");
        }
    }
}