用java Swing设计一个有增删改查的页面，数据库随便

好的，下面是一个简单的Java Swing界面，其中包括增加、删除、修改和查询数据的功能。数据库使用的是SQLite。

首先，需要在项目中引入SQLite JDBC驱动，然后创建一个SQLite数据库。在本例中，我们创建一个名为"example.db"的数据库，其中包含一个名为"users"的表格，包含三个字段：id、name和age。

下面是完整的Java代码：

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;

public class DatabaseGUI extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;

    // 数据库连接相关
    private final String DB_URL = "jdbc:sqlite:example.db";
    private Connection conn;

    // GUI组件
    private JPanel panelTop, panelBottom;
    private JLabel labelName, labelAge;
    private JTextField textName, textAge;
    private JButton buttonAdd, buttonDelete, buttonUpdate, buttonQuery;
    private JTable table;
    private DefaultTableModel tableModel;

    public DatabaseGUI() {
        // 初始化界面
        setTitle("Database GUI");
        setSize(500, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());

        // 连接数据库
        try {
            conn = DriverManager.getConnection(DB_URL);
            System.out.println("Database connected.");
        } catch (SQLException e) {
            System.err.println("Database connection failed: " + e.getMessage());
        }

        // 创建GUI组件
        panelTop = new JPanel();
        labelName = new JLabel("Name:");
        textName = new JTextField(20);
        labelAge = new JLabel("Age:");
        textAge = new JTextField(10);
        buttonAdd = new JButton("Add");
        buttonDelete = new JButton("Delete");
        buttonUpdate = new JButton("Update");
        buttonQuery = new JButton("Query");
        panelTop.add(labelName);
        panelTop.add(textName);
        panelTop.add(labelAge);
        panelTop.add(textAge);
        panelTop.add(buttonAdd);
        panelTop.add(buttonDelete);
        panelTop.add(buttonUpdate);
        panelTop.add(buttonQuery);
        add(panelTop, BorderLayout.NORTH);

        panelBottom = new JPanel();
        tableModel = new DefaultTableModel();
        tableModel.addColumn("ID");
        tableModel.addColumn("Name");
        tableModel.addColumn("Age");
        table = new JTable(tableModel);
        JScrollPane scrollPane = new JScrollPane(table);
        panelBottom.add(scrollPane);
        add(panelBottom, BorderLayout.CENTER);

        // 注册事件监听器
        buttonAdd.addActionListener(this);
        buttonDelete.addActionListener(this);
        buttonUpdate.addActionListener(this);
        buttonQuery.addActionListener(this);

        // 显示界面
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == buttonAdd) {
            // 添加数据
            String name = textName.getText();
            int age = Integer.parseInt(textAge.getText());
            try {
                PreparedStatement stmt = conn.prepareStatement("INSERT INTO users(name, age) VALUES(?, ?)");
                stmt.setString(1, name);
                stmt.setInt(2, age);
                stmt.executeUpdate();
                stmt.close();
                textName.setText("");
                textAge.setText("");
                JOptionPane.showMessageDialog(this, "Added successfully.");
            } catch (SQLException ex) {
                System.err.println("SQL error: " + ex.getMessage());
            }
        } else if (e.getSource() == buttonDelete) {
            // 删除数据
            int row = table.getSelectedRow();
            if (row != -1) {
                int id = (int) tableModel.getValueAt(row, 0);
                try {
                    PreparedStatement stmt = conn.prepareStatement("DELETE FROM users WHERE id = ?");
                    stmt.setInt(1, id);
                    stmt.executeUpdate();
                    stmt.close();
                    tableModel.removeRow(row);
                    JOptionPane.showMessageDialog(this, "Deleted successfully.");
                } catch (SQLException ex) {
                    System.err.println("SQL error: " + ex.getMessage());
                }
            } else {
                JOptionPane.showMessageDialog(this, "Please select a row to delete.");
            }
        } else if (e.getSource() == buttonUpdate) {
            // 修改数据
            int row = table.getSelectedRow();
            if (row != -1) {
                int id = (int) tableModel.getValueAt(row, 0);
                String name = (String) tableModel.getValueAt(row, 1);
                int age = (int) tableModel.getValueAt(row, 2);
                name = JOptionPane.showInputDialog(this, "Name:", name);
                age = Integer.parseInt(JOptionPane.showInputDialog(this, "Age:", age));
                try {
                    PreparedStatement stmt = conn.prepareStatement("UPDATE users SET name = ?, age = ? WHERE id = ?");
                    stmt.setString(1, name);
                    stmt.setInt(2, age);
                    stmt.setInt(3, id);
                    stmt.executeUpdate();
                    stmt.close();
                    tableModel.setValueAt(name, row, 1);
                    tableModel.setValueAt(age, row, 2);
                    JOptionPane.showMessageDialog(this, "Updated successfully.");
                } catch (SQLException ex) {
                    System.err.println("SQL error: " + ex.getMessage());
                }
            } else {
                JOptionPane.showMessageDialog(this, "Please select a row to update.");
            }
        } else if (e.getSource() == buttonQuery) {
            // 查询数据
            try {
                PreparedStatement stmt = conn.prepareStatement("SELECT * FROM users");
                ResultSet rs = stmt.executeQuery();
                tableModel.setRowCount(0);
                while (rs.next()) {
                    int id = rs.getInt("id");
                    String name = rs.getString("name");
                    int age = rs.getInt("age");
                    Object[] row = { id, name, age };
                    tableModel.addRow(row);
                }
                rs.close();
                stmt.close();
            } catch (SQLException ex) {
                System.err.println("SQL error: " + ex.getMessage());
            }
        }
    }

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

运行程序后，可以看到一个界面，其中包括一个表格和一些按钮。在"Name"和"Age"文本框中输入新的数据，然后点击"Add"按钮可以将数据添加到数据库中。选中表格中的一行数据，然后点击"Delete"按钮可以将该行数据从数据库中删除。同样地，选中表格中的一行数据，然后点击"Update"按钮可以修改该行数据。最后，点击"Query"按钮可以查询数据库中的所有数据并在表格中显示。

请注意，本示例程序的代码只是为了演示用途，实际开发中可能需要进行更多的错误处理和输入验证。