用Java语言，写出利用gui界面实现数据库数据的增删查改功能的示例代码

好的，以下是一个简单的使用Java GUI界面实现数据库数据增删查改的示例代码：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;

import javax.swing.*;
import javax.swing.border.EmptyBorder;

public class DatabaseGUI extends JFrame {

    private JPanel contentPane;
    private JTextField textFieldId;
    private JTextField textFieldName;
    private JTextField textFieldAge;
    private JLabel lblId;
    private JLabel lblName;
    private JLabel lblAge;
    private JButton btnAdd;
    private JButton btnDelete;
    private JButton btnUpdate;
    private JButton btnSearch;
    private JTextArea textArea;

    // 数据库连接信息
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC";
    static final String USER = "root";
    static final String PASS = "123456";

    // 数据库连接对象
    Connection conn = null;
    Statement stmt = null;

    /**
     * 创建GUI应用程序
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            try {
                DatabaseGUI frame = new DatabaseGUI();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        });
    }

    /**
     * 创建应用程序框架
     */
    public DatabaseGUI() {
        setTitle("Database GUI");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        lblId = new JLabel("ID:");
        lblId.setBounds(30, 20, 30, 20);
        contentPane.add(lblId);

        textFieldId = new JTextField();
        textFieldId.setBounds(70, 20, 80, 20);
        contentPane.add(textFieldId);
        textFieldId.setColumns(10);

        lblName = new JLabel("Name:");
        lblName.setBounds(30, 60, 50, 20);
        contentPane.add(lblName);

        textFieldName = new JTextField();
        textFieldName.setBounds(70, 60, 80, 20);
        contentPane.add(textFieldName);
        textFieldName.setColumns(10);

        lblAge = new JLabel("Age:");
        lblAge.setBounds(30, 100, 50, 20);
        contentPane.add(lblAge);

        textFieldAge = new JTextField();
        textFieldAge.setBounds(70, 100, 80, 20);
        contentPane.add(textFieldAge);
        textFieldAge.setColumns(10);

        btnAdd = new JButton("Add");
        btnAdd.setBounds(30, 140, 80, 30);
        contentPane.add(btnAdd);
        btnAdd.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                addData();
            }
        });

        btnDelete = new JButton("Delete");
        btnDelete.setBounds(140, 140, 80, 30);
        contentPane.add(btnDelete);
        btnDelete.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                deleteData();
            }
        });

        btnUpdate = new JButton("Update");
        btnUpdate.setBounds(250, 140, 80, 30);
        contentPane.add(btnUpdate);
        btnUpdate.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                updateData();
            }
        });

        btnSearch = new JButton("Search");
        btnSearch.setBounds(360, 140, 80, 30);
        contentPane.add(btnSearch);
        btnSearch.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                searchData();
            }
        });

        textArea = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(textArea);
        scrollPane.setBounds(30, 180, 410, 70);
        contentPane.add(scrollPane);

        // 初始化连接数据库
        try {
            Class.forName(JDBC_DRIVER);
            conn = DriverManager.getConnection(DB_URL, USER, PASS);
            stmt = conn.createStatement();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 添加数据
     */
    private void addData() {
        String id = textFieldId.getText();
        String name = textFieldName.getText();
        String age = textFieldAge.getText();

        try {
            String sql = "INSERT INTO student (id, name, age) VALUES ('" + id + "', '" + name + "', '" + age + "')";
            stmt.executeUpdate(sql);
            textArea.setText("Add data success!");
        } catch (SQLException e) {
            e.printStackTrace();
            textArea.setText("Add data failed!");
        }
    }

    /**
     * 删除数据
     */
    private void deleteData() {
        String id = textFieldId.getText();

        try {
            String sql = "DELETE FROM student WHERE id='" + id + "'";
            stmt.executeUpdate(sql);
            textArea.setText("Delete data success!");
        } catch (SQLException e) {
            e.printStackTrace();
            textArea.setText("Delete data failed!");
        }
    }

    /**
     * 更新数据
     */
    private void updateData() {
        String id = textFieldId.getText();
        String name = textFieldName.getText();
        String age = textFieldAge.getText();

        try {
            String sql = "UPDATE student SET name='" + name + "', age='" + age + "' WHERE id='" + id + "'";
            stmt.executeUpdate(sql);
            textArea.setText("Update data success!");
        } catch (SQLException e) {
            e.printStackTrace();
            textArea.setText("Update data failed!");
        }
    }

    /**
     * 查找数据
     */
    private void searchData() {
        String id = textFieldId.getText();

        try {
            String sql = "SELECT * FROM student WHERE id='" + id + "'";
            ResultSet rs = stmt.executeQuery(sql);

            if (rs.next()) {
                String name = rs.getString("name");
                String age = rs.getString("age");
                textArea.setText("ID: " + id + "\nName: " + name + "\nAge: " + age);
            } else {
                textArea.setText("Search data failed!");
            }
        } catch (SQLException e) {
            e.printStackTrace();
            textArea.setText("Search data failed!");
        }
    }
}

上述代码中，我们通过调用MySQL数据库的Java驱动程序连接到数据库。然后，我们使用GUI组件创建了一个简单的界面，其中包括文本字段、标签和按钮。对于每个按钮，我们添加了一个事件监听器来处理单击事件并执行相应的操作（添加、删除、更新和查找数据）。最后，我们将文本区域添加到界面中，以显示操作结果。