public class BankAccount {
    // 1. 先定义私有属性
    private final String accountNumber;
    private String ownerName;
    private double balance;

    // 2. 构造方法
    public BankAccount(String accountNumber, String ownerName) {
        this.accountNumber = accountNumber;
        this.ownerName = ownerName;
        this.balance = 0.0; // 初始余额为0
    }

    // 3. 存款操作
    public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
            System.out.println("存款成功！当前余额：" + getBalance());
        } else {
            System.out.println("存款失败，金额必须大于0！");
        }
    }

    // 4. 取款操作（补全完整逻辑）
    public void withdraw(double amount) {
        if (amount > 0 && amount <= balance) {
            balance -= amount;
            System.out.println("取款成功！当前余额：" + getBalance());
        } else {
            System.out.println("取款失败：金额无效或余额不足！");
        }
    }

    // 5. 余额查询方法
    public double getBalance() {
        return balance;
    }

    // 6. 户主姓名修改方法
    public void setOwnerName(String ownerName) {
        this.ownerName = ownerName;
    }

    public String getOwnerName() {
        return ownerName;
    }

    public String getAccountNumber() {
        return accountNumber;
    }
}

// Main类，包含main方法用于测试
class Main {
    public static void main(String[] args) {
        BankAccount account = new BankAccount("622202123456", "张三");
        account.deposit(1000);
        account.withdraw(300);
    }
}