使用java图形用户界面实现 1）当输出正确的账号和密码的时候，才能登录ATM柜员机系统。功能实现： 1.1）查询余额。初始值自己设置； 1.2）取款，每次取款数额有限，且不能透支； 1.3）存款 1.4）修改密码：新密码不能和旧密码相同。只有旧密码输入正确，才能设置新密码。 给出实现代码

以下是一个简单的实现代码，仅供参考：

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class ATMSystem extends JFrame {
    private String username = "admin"; // 设置默认用户名和密码
    private String password = "123456";
    private double balance = 10000; // 设置初始余额
    private JTextField userField = new JTextField(10);
    private JPasswordField pwdField = new JPasswordField(10);
    private JButton loginButton = new JButton("登录");
    private JButton queryButton = new JButton("查询余额");
    private JButton withdrawButton = new JButton("取款");
    private JButton depositButton = new JButton("存款");
    private JButton changePwdButton = new JButton("修改密码");

    public ATMSystem() {
        super("ATM柜员机系统");
        setSize(400, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        setLayout(new GridLayout(3, 2));

        add(new JLabel("用户名："));
        add(userField);
        add(new JLabel("密码："));
        add(pwdField);
        add(loginButton);
        loginButton.addActionListener(new LoginListener());

        queryButton.addActionListener(new QueryListener());
        withdrawButton.addActionListener(new WithdrawListener());
        depositButton.addActionListener(new DepositListener());
        changePwdButton.addActionListener(new ChangePwdListener());
    }

    private class LoginListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            String usernameInput = userField.getText();
            String passwordInput = new String(pwdField.getPassword());
            if (usernameInput.equals(username) && passwordInput.equals(password)) { // 检查用户名和密码是否正确
                JOptionPane.showMessageDialog(null, "登录成功！");
                setVisible(false); // 隐藏登录界面
                showMainMenu(); // 显示主菜单
            } else {
                JOptionPane.showMessageDialog(null, "用户名或密码错误，请重新输入！");
            }
        }
    }

    private class QueryListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            JOptionPane.showMessageDialog(null, "当前余额为：" + balance);
        }
    }

    private class WithdrawListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            String input = JOptionPane.showInputDialog(null, "请输入取款金额：");
            double amount = Double.parseDouble(input);
            if (amount > balance || amount > 1000) { // 检查取款金额是否合法
                JOptionPane.showMessageDialog(null, "取款金额不合法！");
            } else {
                balance -= amount;
                JOptionPane.showMessageDialog(null, "取款成功，当前余额为：" + balance);
            }
        }
    }

    private class DepositListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            String input = JOptionPane.showInputDialog(null, "请输入存款金额：");
            double amount = Double.parseDouble(input);
            balance += amount;
            JOptionPane.showMessageDialog(null, "存款成功，当前余额为：" + balance);
        }
    }

    private class ChangePwdListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            String oldPwd = JOptionPane.showInputDialog(null, "请输入旧密码：");
            if (!oldPwd.equals(password)) { // 检查旧密码是否正确
                JOptionPane.showMessageDialog(null, "旧密码错误！");
                return;
            }
            String newPwd = JOptionPane.showInputDialog(null, "请输入新密码：");
            if (newPwd.equals(password)) { // 检查新密码是否和旧密码相同
                JOptionPane.showMessageDialog(null, "新密码不能和旧密码相同！");
                return;
            }
            password = newPwd; // 更新密码
            JOptionPane.showMessageDialog(null, "密码修改成功！");
        }
    }

    private void showMainMenu() {
        JFrame mainMenu = new JFrame("ATM主菜单");
        mainMenu.setSize(400, 300);
        mainMenu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainMenu.setLocationRelativeTo(null);
        mainMenu.setLayout(new GridLayout(2, 2));

        mainMenu.add(queryButton);
        mainMenu.add(withdrawButton);
        mainMenu.add(depositButton);
        mainMenu.add(changePwdButton);

        mainMenu.setVisible(true);
    }

    public static void main(String[] args) {
        new ATMSystem().setVisible(true);
    }
}

这个代码中包含了登录界面和主菜单界面的设计，以及查询余额、取款、存款、修改密码四个功能的实现。当登录成功后，会隐藏登录界面并显示主菜单界面。每个功能都有对应的监听器实现，点击按钮后会弹出对应的操作界面。注意，这里没有添加密码加密的功能，建议在实际开发中加上。