java实现登录注册

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

public class LoginRegisterGUI {
    private JFrame frame;
    private JPanel panel;
    private JTextField usernameField;
    private JPasswordField passwordField;
    private JButton loginButton, registerButton;

    public LoginRegisterGUI() {
        // 初始化窗口
        frame = new JFrame("用户登录/注册");
        frame.setSize(350, 250);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);

        // 初始化面板
        panel = new JPanel();
        frame.add(panel);
        placeComponents(panel);

        frame.setVisible(true);
    }

    private void placeComponents(JPanel panel) {
        panel.setLayout(null);

        // 用户名标签和输入框
        JLabel userLabel = new JLabel("用户名:");
        userLabel.setBounds(50, 30, 80, 25);
        panel.add(userLabel);

        usernameField = new JTextField(20);
        usernameField.setBounds(140, 30, 150, 25);
        panel.add(usernameField);

        // 密码标签和输入框
        JLabel passwordLabel = new JLabel("密码:");
        passwordLabel.setBounds(50, 70, 80, 25);
        panel.add(passwordLabel);

        passwordField = new JPasswordField(20);
        passwordField.setBounds(140, 70, 150, 25);
        panel.add(passwordField);

        // 登录按钮
        loginButton = new JButton("登录");
        loginButton.setBounds(50, 120, 100, 30);
        panel.add(loginButton);

        // 注册按钮
        registerButton = new JButton("注册");
        registerButton.setBounds(190, 120, 100, 30);
        panel.add(registerButton);

        // 绑定事件
        loginButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                handleLogin();
            }
        });

        registerButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                handleRegister();
            }
        });
    }

    // 处理登录
    private void handleLogin() {
        String username = usernameField.getText();
        String password = new String(passwordField.getPassword());

        if (SQLiteDBHelper.loginUser(username, password)) {
            JOptionPane.showMessageDialog(frame, "登录成功！", "成功", JOptionPane.INFORMATION_MESSAGE);
        } else {
            JOptionPane.showMessageDialog(frame, "用户名或密码错误！", "错误", JOptionPane.ERROR_MESSAGE);
        }
    }

    // 处理注册
    private void handleRegister() {
        String username = usernameField.getText();
        String password = new String(passwordField.getPassword());

        if (SQLiteDBHelper.registerUser(username, password)) {
            JOptionPane.showMessageDialog(frame, "注册成功！", "成功", JOptionPane.INFORMATION_MESSAGE);
        } else {
            JOptionPane.showMessageDialog(frame, "注册失败，用户名可能已存在！", "错误", JOptionPane.ERROR_MESSAGE);
        }
    }

    public static void main(String[] args) {
        // 确保数据库表已创建
        SQLiteDBHelper.createTable();

        // 启动GUI
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new LoginRegisterGUI();
            }
        });
    }
}

import java.sql.*;

public class SQLiteDBHelper {
    private static final String URL = "jdbc:sqlite:users.db";

    // 创建数据库连接
    public static Connection connect() {
        try {
            return DriverManager.getConnection(URL);
        } catch (SQLException e) {
            System.out.println("数据库连接失败: " + e.getMessage());
            return null;
        }
    }

    // 创建用户表
    public static void createTable() {
        String createTableSQL = "CREATE TABLE IF NOT EXISTS users (" +
                "id INTEGER PRIMARY KEY AUTOINCREMENT," +
                "username TEXT NOT NULL UNIQUE," +
                "password TEXT NOT NULL);";

        try (Connection conn = connect(); Statement stmt = conn.createStatement()) {
            stmt.execute(createTableSQL);
        } catch (SQLException e) {
            System.out.println("创建表失败: " + e.getMessage());
        }
    }

    // 用户注册
    public static boolean registerUser(String username, String password) {
        String insertSQL = "INSERT INTO users (username, password) VALUES (?, ?)";

        try (Connection conn = connect();
             PreparedStatement pstmt = conn.prepareStatement(insertSQL)) {
            pstmt.setString(1, username);
            pstmt.setString(2, password);
            pstmt.executeUpdate();
            return true;
        } catch (SQLException e) {
            System.out.println("注册失败: " + e.getMessage());
            return false;
        }
    }

    // 用户登录
    public static boolean loginUser(String username, String password) {
        String querySQL = "SELECT * FROM users WHERE username = ? AND password = ?";

        try (Connection conn = connect();
             PreparedStatement pstmt = conn.prepareStatement(querySQL)) {
            pstmt.setString(1, username);
            pstmt.setString(2, password);
            ResultSet rs = pstmt.executeQuery();
            return rs.next();
        } catch (SQLException e) {
            System.out.println("登录失败: " + e.getMessage());
            return false;
        }
    }
}