Java swing ATM

Java Swing ATM是一个简单的ATM应用程序，使用Java Swing GUI库开发。它允许用户执行以下操作：

1. 登录账户
2. 查看账户余额
3. 存款
4. 取款

下面是一个简单的Java Swing ATM示例：

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

public class ATM extends JFrame implements ActionListener {
    private JTextField txtUser;
    private JPasswordField txtPass;
    private JButton btnLogin, btnDeposit, btnWithdraw, btnBalance;
    private JLabel lblStatus, lblAmount;
    private double balance = 0;

    public ATM() {
        setTitle("ATM");
        setSize(400, 250);
        setLayout(new GridLayout(4, 2));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel lblUser = new JLabel("User:");
        add(lblUser);

        txtUser = new JTextField();
        add(txtUser);

        JLabel lblPass = new JLabel("Password:");
        add(lblPass);

        txtPass = new JPasswordField();
        add(txtPass);

        btnLogin = new JButton("Login");
        btnLogin.addActionListener(this);
        add(btnLogin);

        btnDeposit = new JButton("Deposit");
        btnDeposit.addActionListener(this);
        add(btnDeposit);

        btnWithdraw = new JButton("Withdraw");
        btnWithdraw.addActionListener(this);
        add(btnWithdraw);

        btnBalance = new JButton("Balance");
        btnBalance.addActionListener(this);
        add(btnBalance);

        lblStatus = new JLabel("");
        add(lblStatus);

        lblAmount = new JLabel("");
        add(lblAmount);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == btnLogin) {
            String user = txtUser.getText();
            String pass = new String(txtPass.getPassword());

            if (user.equals("admin") && pass.equals("1234")) {
                lblStatus.setText("Login successful.");
                btnDeposit.setEnabled(true);
                btnWithdraw.setEnabled(true);
                btnBalance.setEnabled(true);
            } else {
                lblStatus.setText("Invalid username or password.");
                btnDeposit.setEnabled(false);
                btnWithdraw.setEnabled(false);
                btnBalance.setEnabled(false);
            }
        } else if (e.getSource() == btnDeposit) {
            String amount = JOptionPane.showInputDialog("Enter amount to deposit:");
            double deposit = Double.parseDouble(amount);
            balance += deposit;
            lblAmount.setText("Balance: " + balance);
        } else if (e.getSource() == btnWithdraw) {
            String amount = JOptionPane.showInputDialog("Enter amount to withdraw:");
            double withdraw = Double.parseDouble(amount);
            if (withdraw > balance) {
                lblStatus.setText("Insufficient funds.");
            } else {
                balance -= withdraw;
                lblAmount.setText("Balance: " + balance);
            }
        } else if (e.getSource() == btnBalance) {
            lblAmount.setText("Balance: " + balance);
        }
    }

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

在该示例中，我们创建了一个带有文本框、密码框和按钮的窗体。用户可以输入用户名和密码并点击“登录”按钮来登录账户。如果登录成功，则用户可以点击“存款”、“取款”和“余额”按钮来执行相应的操作。存款和取款操作将弹出一个对话框，要求用户输入金额。账户余额将在标签中显示。