实验目标 掌握Java Swing图形用户界面编程 实验步骤 1. 实现页面菜单，菜单项包括按名字读取、按学号读取、按班级读取； 2. 实现搜索框，用于输入名字或学号，根据名字或学号查询学生信息； 3. 实现班级下拉列表，用于选择班级并按班级查询学生信息。 4. 实现学生信息展示功能，展示从数据库中查询到的学生信息

； 以下是一个简单的Java Swing图形用户界面编程示例，实现了以上的四个功能： ```java import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.sql.*; public class StudentInfoGUI extends JFrame implements ActionListener { private static final String DB_URL = "jdbc:mysql://localhost:3306/student_db"; private static final String DB_USER = "root"; private static final String DB_PASSWORD = "root"; private static final String[] CLASS_OPTIONS = {"Class 1", "Class 2", "Class 3"}; private JLabel nameLabel, idLabel, classLabel; private JTextField nameField, idField; private JComboBox<String> classComboBox; private JButton searchButton; private JTextArea resultArea; public StudentInfoGUI() { super("Student Info"); // 创建菜单栏 JMenuBar menuBar = new JMenuBar(); JMenu fileMenu = new JMenu("File"); JMenuItem nameItem = new JMenuItem("Search by Name"); JMenuItem idItem = new JMenuItem("Search by ID"); JMenuItem classItem = new JMenuItem("Search by Class"); nameItem.addActionListener(this); idItem.addActionListener(this); classItem.addActionListener(this); fileMenu.add(nameItem); fileMenu.add(idItem); fileMenu.add(classItem); menuBar.add(fileMenu); setJMenuBar(menuBar); // 创建搜索面板 JPanel searchPanel = new JPanel(new FlowLayout(FlowLayout.LEFT)); nameLabel = new JLabel("Name:"); idLabel = new JLabel("ID:"); nameField = new JTextField(10); idField = new JTextField(10); searchButton = new JButton("Search"); searchButton.addActionListener(this); searchPanel.add(nameLabel); searchPanel.add(nameField); searchPanel.add(idLabel); searchPanel.add(idField); searchPanel.add(searchButton); // 创建班级下拉列表 classLabel = new JLabel("Class:"); classComboBox = new JComboBox<>(CLASS_OPTIONS); classComboBox.addActionListener(this); // 创建结果文本域 resultArea = new JTextArea(20, 50); resultArea.setEditable(false); // 将组件添加到容器中 Container contentPane = getContentPane(); contentPane.setLayout(new BorderLayout()); contentPane.add(searchPanel, BorderLayout.NORTH); JPanel classPanel = new JPanel(); classPanel.add(classLabel); classPanel.add(classComboBox); contentPane.add(classPanel, BorderLayout.WEST); contentPane.add(new JScrollPane(resultArea), BorderLayout.CENTER); setSize(600, 400); setLocationRelativeTo(null); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } @Override public void actionPerformed(ActionEvent e) { if (e.getSource() == searchButton) { String name = nameField.getText().trim(); String id = idField.getText().trim(); String className = (String) classComboBox.getSelectedItem(); search(name, id, className); } else if (e.getActionCommand().equals("Search by Name")) { nameField.requestFocus(); } else if (e.getActionCommand().equals("Search by ID")) { idField.requestFocus(); } else if (e.getActionCommand().equals("Search by Class")) { classComboBox.requestFocus(); } } private void search(String name, String id, String className) { resultArea.setText(""); String sql = "SELECT * FROM students WHERE name LIKE ? AND id LIKE ? AND class LIKE ?"; try (Connection conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD); PreparedStatement stmt = conn.prepareStatement(sql)) { stmt.setString(1, "%" + name + "%"); stmt.setString(2, "%" + id + "%"); stmt.setString(3, "%" + className + "%"); ResultSet rs = stmt.executeQuery(); while (rs.next()) { String result = String.format("Name: %s\nID: %s\nClass: %s\nScore: %d\n\n", rs.getString("name"), rs.getString("id"), rs.getString("class"), rs.getInt("score")); resultArea.append(result); } if (resultArea.getText().isEmpty()) { resultArea.setText("No records found."); } } catch (SQLException ex) { ex.printStackTrace(); JOptionPane.showMessageDialog(this, "Error: " + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE); } } public static void main(String[] args) { StudentInfoGUI gui = new StudentInfoGUI(); gui.setVisible(true); } } ``` 在本示例中，我们使用了Java Swing的各种组件，如JLabel、JTextField、JComboBox、JButton、JTextArea等，同时还实现了ActionListener接口以响应用户事件。在搜索函数中，我们使用了Java JDBC连接MySQL数据库，并使用PreparedStatement执行带参数的SQL查询语句，以避免SQL注入攻击。