用javaswing写一个登录代码

好的，下面是一个简单的Java Swing登录代码示例：

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

public class LoginFrame extends JFrame implements ActionListener {
    private JLabel accountLabel = new JLabel("账号");
    private JLabel passwordLabel = new JLabel("密码");
    private JTextField accountField = new JTextField(20);
    private JPasswordField passwordField = new JPasswordField(20);
    private JButton loginButton = new JButton("登录");
    private JButton cancelButton = new JButton("取消");

    public LoginFrame() {
        setTitle("登录");
        setSize(300, 200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints constraints = new GridBagConstraints();
        constraints.insets = new Insets(5, 5, 5, 5);

        constraints.gridx = 0;
        constraints.gridy = 0;
        panel.add(accountLabel, constraints);

        constraints.gridx = 1;
        constraints.gridy = 0;
        panel.add(accountField, constraints);

        constraints.gridx = 0;
        constraints.gridy = 1;
        panel.add(passwordLabel, constraints);

        constraints.gridx = 1;
        constraints.gridy = 1;
        panel.add(passwordField, constraints);

        constraints.gridx = 0;
        constraints.gridy = 2;
        panel.add(loginButton, constraints);

        constraints.gridx = 1;
        constraints.gridy = 2;
        panel.add(cancelButton, constraints);

        add(panel, BorderLayout.CENTER);

        loginButton.addActionListener(this);
        cancelButton.addActionListener(this);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == loginButton) {
            String account = accountField.getText();
            String password = new String(passwordField.getPassword());
            // 在这里实现登录验证逻辑
            if (account.equals("admin") && password.equals("admin123")) {
                JOptionPane.showMessageDialog(this, "登录成功");
            } else {
                JOptionPane.showMessageDialog(this, "用户名或密码错误");
            }
        } else if (e.getSource() == cancelButton) {
            System.exit(0);
        }
    }

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

这个代码示例实现了一个简单的登录界面，包含了账号、密码、登录和取消按钮。当用户点击登录按钮时，程序会获取账号和密码并进行验证，如果验证通过则弹出登录成功提示框，否则弹出用户名或密码错误提示框。如果用户点击取消按钮，则程序退出。

这只是一个简单的示例，实际的登录功能可能还需要更多的验证和处理逻辑。您可以根据实际情况进行修改和扩展。