写一个java学生管理系统，GUI界面，链接数据库的代码

好的，下面是一个简单的Java学生管理系统的GUI界面和链接数据库的代码，您可以参考：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;

public class StudentManagementSystemGUI extends JFrame implements ActionListener {
    private JLabel nameLabel, ageLabel, genderLabel, idLabel;
    private JTextField nameText, ageText, genderText, idText;
    private JButton addButton, updateButton, deleteButton, searchButton, clearButton;
    private JTextArea resultTextArea;
    private Connection conn;
    private ResultSet rs;

    public StudentManagementSystemGUI() {
        // 设置窗口标题
        setTitle("学生管理系统");

        // 创建组件
        nameLabel = new JLabel("姓名：");
        ageLabel = new JLabel("年龄：");
        genderLabel = new JLabel("性别：");
        idLabel = new JLabel("学号：");
        nameText = new JTextField(20);
        ageText = new JTextField(20);
        genderText = new JTextField(20);
        idText = new JTextField(20);
        addButton = new JButton("添加");
        updateButton = new JButton("修改");
        deleteButton = new JButton("删除");
        searchButton = new JButton("查询");
        clearButton = new JButton("清空");
        resultTextArea = new JTextArea(10, 30);

        // 添加事件监听器
        addButton.addActionListener(this);
        updateButton.addActionListener(this);
        deleteButton.addActionListener(this);
        searchButton.addActionListener(this);
        clearButton.addActionListener(this);

        // 创建布局
        JPanel panel1 = new JPanel();
        panel1.setLayout(new GridLayout(4, 2));
        panel1.add(nameLabel);
        panel1.add(nameText);
        panel1.add(ageLabel);
        panel1.add(ageText);
        panel1.add(genderLabel);
        panel1.add(genderText);
        panel1.add(idLabel);
        panel1.add(idText);

        JPanel panel2 = new JPanel();
        panel2.add(addButton);
        panel2.add(updateButton);
        panel2.add(deleteButton);
        panel2.add(searchButton);
        panel2.add(clearButton);

        JPanel panel3 = new JPanel();
        panel3.add(resultTextArea);

        // 将组件添加到窗口上
        setLayout(new BorderLayout());
        add(panel1, BorderLayout.NORTH);
        add(panel2, BorderLayout.CENTER);
        add(panel3, BorderLayout.SOUTH);

        // 连接数据库
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/student", "root", "123456");
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        // 设置窗口属性
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400, 400);
        setLocationRelativeTo(null);
        setVisible(true);
    }

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

    @Override
    public void actionPerformed(ActionEvent e) {
        // 处理按钮事件
        if (e.getSource() == addButton) {
            addStudent();
        } else if (e.getSource() == updateButton) {
            updateStudent();
        } else if (e.getSource() == deleteButton) {
            deleteStudent();
        } else if (e.getSource() == searchButton) {
            searchStudent();
        } else if (e.getSource() == clearButton) {
            clearFields();
        }
    }

    private void addStudent() {
        try {
            String name = nameText.getText();
            int age = Integer.parseInt(ageText.getText());
            String gender = genderText.getText();
            String id = idText.getText();

            PreparedStatement ps = conn.prepareStatement("INSERT INTO student VALUES (?, ?, ?, ?)");
            ps.setString(1, id);
            ps.setString(2, name);
            ps.setInt(3, age);
            ps.setString(4, gender);

            int rows = ps.executeUpdate();
            if (rows > 0) {
                resultTextArea.setText("添加成功！");
            } else {
                resultTextArea.setText("添加失败！");
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void updateStudent() {
        try {
            String name = nameText.getText();
            int age = Integer.parseInt(ageText.getText());
            String gender = genderText.getText();
            String id = idText.getText();

            PreparedStatement ps = conn.prepareStatement("UPDATE student SET name=?, age=?, gender=? WHERE id=?");
            ps.setString(1, name);
            ps.setInt(2, age);
            ps.setString(3, gender);
            ps.setString(4, id);

            int rows = ps.executeUpdate();
            if (rows > 0) {
                resultTextArea.setText("修改成功！");
            } else {
                resultTextArea.setText("修改失败！");
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void deleteStudent() {
        try {
            String id = idText.getText();

            PreparedStatement ps = conn.prepareStatement("DELETE FROM student WHERE id=?");
            ps.setString(1, id);

            int rows = ps.executeUpdate();
            if (rows > 0) {
                resultTextArea.setText("删除成功！");
            } else {
                resultTextArea.setText("删除失败！");
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void searchStudent() {
        try {
            String id = idText.getText();

            PreparedStatement ps = conn.prepareStatement("SELECT * FROM student WHERE id=?");
            ps.setString(1, id);

            rs = ps.executeQuery();
            if (rs.next()) {
                nameText.setText(rs.getString("name"));
                ageText.setText(rs.getString("age"));
                genderText.setText(rs.getString("gender"));
            } else {
                resultTextArea.setText("没有找到该学生！");
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void clearFields() {
        nameText.setText("");
        ageText.setText("");
        genderText.setText("");
        idText.setText("");
        resultTextArea.setText("");
    }
}

这段代码实现了基本的增删改查功能，您可以根据自己的需要修改和完善。同时，需要注意的是，代码中连接的是MySQL数据库，您需要先安装和配置好MySQL，并创建一个名为"student"的数据库，以及一个名为"student"的表，表结构如下：

CREATE TABLE student (
    id VARCHAR(20) PRIMARY KEY,
    name VARCHAR(20),
    age INT,
    gender VARCHAR(10)
);

另外，为了能够成功连接MySQL数据库，您需要下载并添加MySQL的JDBC驱动包到项目中。