Swing实现简单的图书馆登界面

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

class Login1 {
    public static void main(String[] args) throws SQLException, ClassNotFoundException {
        DataBaseConnect connect = new DataBaseConnect();
//        connect.getConnection();
//       connect.Insert("黄洪飞","123456");
        connect.Insert("胡彩月", "123456");
//       connect.Delete("haungg","23132");
        Login login = new Login("图书管理");
    }
}

//class DataBaseConnect {
//    static private String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
//    static private String DB_URl = "jdbc:mysql://root@localhost:3306/library?characterEncoding=utf8";
//    static final String USER = "root";
//    static final String PASS = "123456";
//    Connection connection;
//    PreparedStatement sql;
//    ResultSet resultSet;
//
//    public Connection getConnection() throws ClassNotFoundException, SQLException {
//        Class.forName(JDBC_DRIVER);
//        connection = DriverManager.getConnection(DB_URl, USER, PASS);
//        System.out.println("数据库链接成功");
//        return connection;
//    }
//
//    public void CloseConnection(Connection connection) throws SQLException {
//        if (connection != null)
//            connection.close();
//    }
//
//    public boolean Select(String user) throws SQLException, ClassNotFoundException {
//        connection = this.getConnection();
//        sql = connection.prepareStatement("select *from library.db_book ");
//        int flag = 0;
//        try {
//            resultSet = sql.executeQuery();
//            while (resultSet.next()) {
//                String username = resultSet.getString("username");
//                if (user.equals(username))
//                    flag = 1;
//            }
//        } catch (Exception e) {
//            e.printStackTrace();
//
//        }
//        if (flag == 0)
//            return true;
//        else
//            return false;
//    }
//
//    public boolean Insert(String user, String password) throws SQLException, ClassNotFoundException {
//        connection = this.getConnection();
////     sql=connection.prepareStatement("insert into library.db_book(ID,username, password) values(?,?,?)");
//        boolean result = this.Select(user);
//        if (result) {
//            sql = connection.prepareStatement("insert into library.db_book(username, password) values(?,?)");
////          sql.setInt(1,0);
//            sql.setString(1, user);
//            sql.setString(2, password);
//            sql.executeUpdate();
//            return true;
//        } else {
//            return false;
//        }
//    }
//
//    public void Delete(String user, String password) throws SQLException, ClassNotFoundException {
//        connection = this.getConnection();
//        boolean result = this.Select(user);
//        if (!result) {
//            sql = connection.prepareStatement("delete from library.db_book where username=?");
//            sql.setString(1, user);
////           sql.setString(2,password);
//            sql.executeUpdate();
//
//        }
//
//    }
//}
//}
class Login extends JFrame implements ActionListener {

    //登录、注册、取消
    JButton btnLogin, btnRegister, btnCancel;
    JPanel pnlSouth, pnlNorth, pnlCenter, pnlCenter1, pnlCenter2;//注册面板
    JLabel jLabel1, jLabelUser, jLabelPassWord;
    JTextField jTextFieldUser, jTextFieldPassWord;

    public Login(String title) {
        super(title);
        pnlNorth = new JPanel();
        jLabel1 = new JLabel("欢迎进入图书管理系统！");
        pnlNorth.add(jLabel1);
        this.add(pnlNorth, BorderLayout.NORTH);
        //登录
        pnlCenter = new JPanel();
        pnlCenter1 = new JPanel();
        pnlCenter2 = new JPanel();
        pnlCenter.setLayout(new BorderLayout());
        //用户
        jLabelUser = new JLabel(" 用 户：");
        jTextFieldUser = new JTextField(15);
        pnlCenter1.add(jLabelUser);
        pnlCenter1.add(jTextFieldUser);
        pnlCenter.add(pnlCenter1, BorderLayout.NORTH);
        //密码
        jLabelPassWord = new JLabel("密 码：");
        jTextFieldPassWord = new JTextField(15);
        pnlCenter2.add(jLabelPassWord);
        pnlCenter2.add(jTextFieldPassWord);
        pnlCenter.add(pnlCenter2, BorderLayout.CENTER);
        this.add(pnlCenter, BorderLayout.CENTER);
        pnlSouth = new JPanel();
        btnLogin = new JButton("登录");
        btnLogin.addActionListener(this);
        btnRegister = new JButton("注册");
        btnRegister.addActionListener(this);
        btnCancel = new JButton("取消");
        btnCancel.addActionListener(this);
        pnlSouth.add(btnLogin);
        pnlSouth.add(btnRegister);
        pnlSouth.add(btnCancel);
        this.add(pnlSouth, BorderLayout.SOUTH);
        this.setSize(400, 200);
        this.setVisible(true);
        this.setResizable(false);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        //登录
        DataBaseConnect connect = new DataBaseConnect();
        if (e.getSource() == btnLogin) {
            String user = jTextFieldUser.getText();
            if (user.equals("")) {
                JOptionPane.showMessageDialog(this, "请输入账号");
            } else if (user != null) {
                try {
                    if (!connect.Select(user)) {
                        JOptionPane.showMessageDialog(this, "恭喜您，登陆成功！");
                        setVisible(false);
                        dispose();
                        new MenuJFrame();
                    }
                    else
                        JOptionPane.showMessageDialog(this, "该账号不存在！");
                } catch (SQLException | ClassNotFoundException ex) {
                    ex.printStackTrace();
                }
            }
        }
        //注册
        else if (e.getSource() == btnRegister) {
            String user = jTextFieldUser.getText();
            String password = jTextFieldPassWord.getText();
            try {
                boolean result = connect.Insert(user, password);
                if (!result) {
                    connect.Insert(user, password);
                    JOptionPane.showMessageDialog(this, "恭喜,注册成功");
//                    setVisible(false);
//                    dispose();
//                    new MenuJFrame();

                } else {
                    JOptionPane.showMessageDialog(this, "该账号已经存在！");
                }
            } catch (SQLException | ClassNotFoundException ex) {
                ex.printStackTrace();
            }

        }
        else if (e.getSource()==btnCancel){
            JOptionPane.showMessageDialog(this,"告辞");
            System.exit(0);
        }
    }
}

import java.sql.*;

class DataBaseConnect {
    static private String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
    static private String DB_URl = "jdbc:mysql://root@localhost:3306/library?characterEncoding=utf8";
    static final String USER = "root";
    static final String PASS = "123456";
    Connection connection;
    PreparedStatement sql;
    ResultSet resultSet;

    public Connection getConnection() throws SQLException, ClassNotFoundException {
        Class.forName(JDBC_DRIVER);
        connection = DriverManager.getConnection(DB_URl, USER, PASS);
        System.out.println("数据库链接成功");
        return connection;
    }

    public void CloseConnection(Connection connection) throws SQLException {
        if (connection != null)
            connection.close();
    }

    public boolean Select(String user) throws SQLException, ClassNotFoundException {
        connection = this.getConnection();
        sql = connection.prepareStatement("select *from library.db_账户 ");
        int flag = 0;
        try {
            resultSet = sql.executeQuery();
            while (resultSet.next()) {
                String username = resultSet.getString("username");
                if (user.equals(username))
                    flag = 1;
            }
        } catch (Exception e) {
            e.printStackTrace();

        }
        if (flag == 0)
            return true;
        else
            return false;
    }

    public boolean Insert(String user, String password) throws SQLException, ClassNotFoundException {
        connection = this.getConnection();
//     sql=connection.prepareStatement("insert into library.db_book(ID,username, password) values(?,?,?)");
        boolean result = this.Select(user);
        if (result) {
            sql = connection.prepareStatement("insert into library.db_账户(username, password) values(?,?)");
//          sql.setInt(1,0);
            sql.setString(1, user);
            sql.setString(2, password);
            sql.executeUpdate();
            return true;
        } else {
            return false;
        }
    }

    public void Delete(String user, String password) throws SQLException, ClassNotFoundException {
        connection = this.getConnection();
        boolean result = this.Select(user);
        if (!result) {
            sql = connection.prepareStatement("delete from library.db_账户 where username=?");
            sql.setString(1, user);
//           sql.setString(2,password);
            sql.executeUpdate();

        }
    }

    public String AddBook(String bookName, String bookAuthor, String bookTime, int number) throws SQLException, ClassNotFoundException {
        connection = this.getConnection();
        sql = connection.prepareStatement("insert into library.db_book(BookName, BookAuthor, BookTime, BookNumber) values(?,?,?,?)");
        sql.setString(1, bookName);
        sql.setString(2, bookAuthor);
        sql.setString(3, bookTime);
        sql.setInt(4, number);
        sql.executeUpdate();

        return "添加书籍成功";
    }

    public boolean SelectBook(String bookName) throws SQLException, ClassNotFoundException {
        connection = this.getConnection();
        sql = connection.prepareStatement("select *from library.db_book ");
        resultSet = sql.executeQuery();
        int flag = 0;
        while (resultSet.next()) {
            String book = resultSet.getString("BookName");
            if (bookName.equals(book))
                flag = 1;
        }
        if (flag == 1)
            return true;
        else
            return false;
    }
    public void DeleteBook(String bookName) throws SQLException, ClassNotFoundException {
        connection=this.getConnection();
        sql = connection.prepareStatement("delete from library.db_book where BookName=?");
        sql.setString(1, bookName);
//           sql.setString(2,password);
        sql.executeUpdate();

    }
}