Java编写图形用户界面的图书借阅系统

好的，我会提供一个简单的Java图书借阅系统的代码示例，供您参考。

首先，需要使用Java的GUI库，这里我们选择使用Swing。接下来，我们需要设计数据库的结构，这里我们使用MySQL作为数据库。在MySQL中，我们需要创建三张表：books、users、borrow_records，用于存储书籍信息、用户信息和借阅记录。

books表结构如下：

CREATE TABLE books (
  id INT(11) NOT NULL AUTO_INCREMENT,
  name VARCHAR(50) NOT NULL,
  author VARCHAR(50) NOT NULL,
  publish_date DATE NOT NULL,
  price DOUBLE NOT NULL,
  stock INT(11) NOT NULL,
  PRIMARY KEY (id)
);

users表结构如下：

CREATE TABLE users (
  id INT(11) NOT NULL AUTO_INCREMENT,
  username VARCHAR(50) NOT NULL,
  password VARCHAR(50) NOT NULL,
  type INT(11) NOT NULL,
  PRIMARY KEY (id)
);

borrow_records表结构如下：

CREATE TABLE borrow_records (
  id INT(11) NOT NULL AUTO_INCREMENT,
  user_id INT(11) NOT NULL,
  book_id INT(11) NOT NULL,
  borrow_date DATE NOT NULL,
  return_date DATE DEFAULT NULL,
  PRIMARY KEY (id),
  FOREIGN KEY (user_id) REFERENCES users(id),
  FOREIGN KEY (book_id) REFERENCES books(id)
);

接下来，我们需要编写Java代码，使用Swing库实现图书借阅系统。

首先，我们需要创建一个登录界面，让用户输入用户名和密码以进行登录。代码如下：

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

public class LoginFrame extends JFrame {

    private JLabel userLabel;
    private JTextField userField;
    private JLabel passwordLabel;
    private JPasswordField passwordField;
    private JButton loginButton;

    public LoginFrame() {
        setTitle("图书借阅系统登录");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        userLabel = new JLabel("用户名：");
        userField = new JTextField(20);
        passwordLabel = new JLabel("密码：");
        passwordField = new JPasswordField(20);
        loginButton = new JButton("登录");

        setLayout(new GridLayout(3, 2));
        add(userLabel);
        add(userField);
        add(passwordLabel);
        add(passwordField);
        add(new JLabel());
        add(loginButton);

        loginButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String username = userField.getText();
                String password = new String(passwordField.getPassword());
                if (validateUser(username, password)) {
                    dispose();
                    new MainFrame();
                } else {
                    JOptionPane.showMessageDialog(LoginFrame.this, "用户名或密码错误！", "错误", JOptionPane.ERROR_MESSAGE);
                }
            }
        });

        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

    private boolean validateUser(String username, String password) {
        // TODO: 验证用户名和密码
        return true;
    }

    public static void main(String[] args) {
        new LoginFrame();
    }
}

在登录成功后，我们需要创建一个主界面，用于实现图书借阅、归还和查询等功能。代码如下：

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

public class MainFrame extends JFrame {

    private JTabbedPane tabbedPane;

    public MainFrame() {
        setTitle("图书借阅系统");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        tabbedPane = new JTabbedPane();

        BooksPanel booksPanel = new BooksPanel();
        BorrowPanel borrowPanel = new BorrowPanel();
        ReturnPanel returnPanel = new ReturnPanel();
        QueryPanel queryPanel = new QueryPanel();

        tabbedPane.addTab("图书管理", booksPanel);
        tabbedPane.addTab("借阅管理", borrowPanel);
        tabbedPane.addTab("归还管理", returnPanel);
        tabbedPane.addTab("查询统计", queryPanel);

        add(tabbedPane);

        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

    public static void main(String[] args) {
        new MainFrame();
    }
}

然后，我们需要编写BooksPanel、BorrowPanel、ReturnPanel和QueryPanel等面板类，用于实现具体的功能。这里以BooksPanel为例，代码如下：

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;
import java.util.Vector;

public class BooksPanel extends JPanel {

    private JTable booksTable;
    private DefaultTableModel booksTableModel;
    private JButton addButton;
    private JButton editButton;
    private JButton deleteButton;

    public BooksPanel() {
        setLayout(new BorderLayout());

        booksTableModel = new DefaultTableModel();
        booksTableModel.addColumn("编号");
        booksTableModel.addColumn("书名");
        booksTableModel.addColumn("作者");
        booksTableModel.addColumn("出版日期");
        booksTableModel.addColumn("价格");
        booksTableModel.addColumn("库存");

        booksTable = new JTable(booksTableModel);
        JScrollPane scrollPane = new JScrollPane(booksTable);

        add(scrollPane, BorderLayout.CENTER);

        JPanel buttonPanel = new JPanel();

        addButton = new JButton("添加");
        editButton = new JButton("编辑");
        deleteButton = new JButton("删除");

        buttonPanel.add(addButton);
        buttonPanel.add(editButton);
        buttonPanel.add(deleteButton);

        add(buttonPanel, BorderLayout.SOUTH);

        addButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String name = JOptionPane.showInputDialog(BooksPanel.this, "请输入书名：");
                String author = JOptionPane.showInputDialog(BooksPanel.this, "请输入作者：");
                String publishDate = JOptionPane.showInputDialog(BooksPanel.this, "请输入出版日期（yyyy-MM-dd）：");
                double price = Double.parseDouble(JOptionPane.showInputDialog(BooksPanel.this, "请输入价格："));
                int stock = Integer.parseInt(JOptionPane.showInputDialog(BooksPanel.this, "请输入库存："));

                Connection connection = null;
                PreparedStatement statement = null;

                try {
                    Class.forName("com.mysql.jdbc.Driver");
                    connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/bookdb", "root", "123456");

                    String sql = "INSERT INTO books (name, author, publish_date, price, stock) VALUES (?, ?, ?, ?, ?)";
                    statement = connection.prepareStatement(sql);
                    statement.setString(1, name);
                    statement.setString(2, author);
                    statement.setDate(3, Date.valueOf(publishDate));
                    statement.setDouble(4, price);
                    statement.setInt(5, stock);
                    statement.executeUpdate();

                    loadBooks();

                } catch (SQLException ex) {
                    ex.printStackTrace();
                    JOptionPane.showMessageDialog(BooksPanel.this, "添加失败！", "错误", JOptionPane.ERROR_MESSAGE);
                } catch (ClassNotFoundException ex) {
                    ex.printStackTrace();
                } finally {
                    try {
                        if (statement != null) statement.close();
                        if (connection != null) connection.close();
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        editButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int rowIndex = booksTable.getSelectedRow();
                if (rowIndex == -1) {
                    JOptionPane.showMessageDialog(BooksPanel.this, "请选择要编辑的书籍！", "提示", JOptionPane.WARNING_MESSAGE);
                    return;
                }

                int id = (int) booksTableModel.getValueAt(rowIndex, 0);
                String name = JOptionPane.showInputDialog(BooksPanel.this, "请输入书名：", booksTableModel.getValueAt(rowIndex, 1));
                String author = JOptionPane.showInputDialog(BooksPanel.this, "请输入作者：", booksTableModel.getValueAt(rowIndex, 2));
                String publishDate = JOptionPane.showInputDialog(BooksPanel.this, "请输入出版日期（yyyy-MM-dd）：", booksTableModel.getValueAt(rowIndex, 3));
                double price = Double.parseDouble(JOptionPane.showInputDialog(BooksPanel.this, "请输入价格：", booksTableModel.getValueAt(rowIndex, 4)));
                int stock = Integer.parseInt(JOptionPane.showInputDialog(BooksPanel.this, "请输入库存：", booksTableModel.getValueAt(rowIndex, 5)));

                Connection connection = null;
                PreparedStatement statement = null;

                try {
                    Class.forName("com.mysql.jdbc.Driver");
                    connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/bookdb", "root", "123456");

                    String sql = "UPDATE books SET name=?, author=?, publish_date=?, price=?, stock=? WHERE id=?";
                    statement = connection.prepareStatement(sql);
                    statement.setString(1, name);
                    statement.setString(2, author);
                    statement.setDate(3, Date.valueOf(publishDate));
                    statement.setDouble(4, price);
                    statement.setInt(5, stock);
                    statement.setInt(6, id);
                    statement.executeUpdate();

                    loadBooks();

                } catch (SQLException ex) {
                    ex.printStackTrace();
                    JOptionPane.showMessageDialog(BooksPanel.this, "编辑失败！", "错误", JOptionPane.ERROR_MESSAGE);
                } catch (ClassNotFoundException ex) {
                    ex.printStackTrace();
                } finally {
                    try {
                        if (statement != null) statement.close();
                        if (connection != null) connection.close();
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        deleteButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int rowIndex = booksTable.getSelectedRow();
                if (rowIndex == -1) {
                    JOptionPane.showMessageDialog(BooksPanel.this, "请选择要删除的书籍！", "提示", JOptionPane.WARNING_MESSAGE);
                    return;
                }

                int id = (int) booksTableModel.getValueAt(rowIndex, 0);

                Connection connection = null;
                PreparedStatement statement = null;

                try {
                    Class.forName("com.mysql.jdbc.Driver");
                    connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/bookdb", "root", "123456");

                    String sql = "DELETE FROM books WHERE id=?";
                    statement = connection.prepareStatement(sql);
                    statement.setInt(1, id);
                    statement.executeUpdate();

                    loadBooks();

                } catch (SQLException ex) {
                    ex.printStackTrace();
                    JOptionPane.showMessageDialog(BooksPanel.this, "删除失败！", "错误", JOptionPane.ERROR_MESSAGE);
                } catch (ClassNotFoundException ex) {
                    ex.printStackTrace();
                } finally {
                    try {
                        if (statement != null) statement.close();
                        if (connection != null) connection.close();
                    } catch (SQLException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        loadBooks();
    }

    private void loadBooks() {
        Connection connection = null;
        Statement statement = null;

        try {
            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/bookdb", "root", "123456");

            String sql = "SELECT * FROM books";
            statement = connection.createStatement();
            ResultSet resultSet = statement.executeQuery(sql);

            booksTableModel.setRowCount(0);

            while (resultSet.next()) {
                Vector<Object> rowData = new Vector<>();
                rowData.add(resultSet.getInt("id"));
                rowData.add(resultSet.getString("name"));
                rowData.add(resultSet.getString("author"));
                rowData.add(resultSet.getDate("publish_date"));
                rowData.add(resultSet.getDouble("price"));
                rowData.add(resultSet.getInt("stock"));

                booksTableModel.addRow(rowData);
            }

        } catch (SQLException ex) {
            ex.printStackTrace();
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        } finally {
            try {
                if (statement != null) statement.close();
                if (connection != null) connection.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
    }
}

这里只展示了BooksPanel的代码，其他面板类的代码类似。需要注意的是，在代码中需要使用JDBC连接数据库进行数据的增删改查操作，同时需要注意异常处理和数据类型转换等问题。

希望这个例子能够帮助您了解Java图书借阅系统的开发过程和技术点。