帮我写一个五子棋的Java代码，包含换背景的功能

好的，以下是一个简单的五子棋的Java代码示例，包含了换背景的功能：

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

public class Gobang extends JFrame implements ActionListener {

    private JButton[][] board;  // 棋盘
    private int[][] gameState;  // 游戏状态数组
    private int currentPlayer;  // 当前玩家，1为黑，2为白
    private ImageIcon blackIcon;  // 黑棋图片
    private ImageIcon whiteIcon;  // 白棋图片
    private JMenuBar menuBar;  // 菜单栏
    private JMenu menu;  // 菜单
    private JMenuItem item;  // 菜单项
    private JRadioButtonMenuItem[] rbItems;  // 单选按钮菜单项
    private ButtonGroup bg;  // 单选按钮组

    public Gobang() {
        setTitle("五子棋");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(500, 500);
        setLocationRelativeTo(null);
        setResizable(false);

        // 初始化棋盘
        board = new JButton[15][15];
        gameState = new int[15][15];
        for (int i = 0; i < 15; i++) {
            for (int j = 0; j < 15; j++) {
                board[i][j] = new JButton();
                board[i][j].setPreferredSize(new Dimension(30, 30));
                board[i][j].addActionListener(this);
                gameState[i][j] = 0;
            }
        }

        // 初始化图片
        blackIcon = new ImageIcon("black.png");
        whiteIcon = new ImageIcon("white.png");

        // 初始化菜单
        menuBar = new JMenuBar();
        menu = new JMenu("背景颜色");
        rbItems = new JRadioButtonMenuItem[3];
        rbItems[0] = new JRadioButtonMenuItem("蓝色", true);
        rbItems[1] = new JRadioButtonMenuItem("绿色");
        rbItems[2] = new JRadioButtonMenuItem("红色");
        bg = new ButtonGroup();
        for (int i = 0; i < 3; i++) {
            rbItems[i].addActionListener(this);
            bg.add(rbItems[i]);
            menu.add(rbItems[i]);
        }
        menuBar.add(menu);
        setJMenuBar(menuBar);

        // 添加组件
        JPanel panel = new JPanel(new GridLayout(15, 15));
        for (int i = 0; i < 15; i++) {
            for (int j = 0; j < 15; j++) {
                panel.add(board[i][j]);
            }
        }
        add(panel);

        // 初始化玩家
        currentPlayer = 1;
    }

    // 处理按钮点击事件
    public void actionPerformed(ActionEvent e) {
        for (int i = 0; i < 15; i++) {
            for (int j = 0; j < 15; j++) {
                if (e.getSource() == board[i][j]) {
                    if (gameState[i][j] == 0) {
                        if (currentPlayer == 1) {
                            board[i][j].setIcon(blackIcon);
                            gameState[i][j] = 1;
                            currentPlayer = 2;
                        } else {
                            board[i][j].setIcon(whiteIcon);
                            gameState[i][j] = 2;
                            currentPlayer = 1;
                        }
                    }
                }
            }
        }

        // 处理菜单点击事件
        for (int i = 0; i < 3; i++) {
            if (e.getSource() == rbItems[i]) {
                switch (i) {
                    case 0:
                        getContentPane().setBackground(Color.BLUE);
                        break;
                    case 1:
                        getContentPane().setBackground(Color.GREEN);
                        break;
                    case 2:
                        getContentPane().setBackground(Color.RED);
                        break;
                }
            }
        }
    }

    public static void main(String[] args) {
        Gobang game = new Gobang();
        game.setVisible(true);
    }

}

这个示例中，我们使用了Java的Swing框架来创建GUI界面，实现了一个简单的五子棋游戏，同时还添加了一个菜单栏，包含了一个单选按钮菜单项，可以切换背景颜色。你可以根据自己的需求修改代码来实现更丰富的功能。