编写以下代码，使用javaswing编写一款五子棋游戏，要求有规则说明

以下是使用Java Swing编写的五子棋游戏代码，包括规则说明：

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

public class Gobang extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private ChessBoard chessBoard;  // 棋盘
    private JButton button1, button2;  // 按钮
    private JLabel label;  // 标签
    private boolean isBlack = true;  // 是否是黑棋先手
    private boolean isOver = false;  // 游戏是否结束

    public Gobang() {
        super("五子棋游戏");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(500, 550);
        setResizable(false);

        chessBoard = new ChessBoard();
        add(chessBoard, BorderLayout.CENTER);

        JPanel panel = new JPanel(new FlowLayout());
        button1 = new JButton("重新开始");
        button1.addActionListener(this);
        panel.add(button1);

        button2 = new JButton("退出游戏");
        button2.addActionListener(this);
        panel.add(button2);

        label = new JLabel("黑方先行");
        panel.add(label);

        add(panel, BorderLayout.SOUTH);
        setVisible(true);
    }

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

    // 实现ActionListener接口的方法
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == button1) {
            chessBoard.restart();
            isBlack = true;
            isOver = false;
            label.setText("黑方先行");
        } else if (e.getSource() == button2) {
            System.exit(0);
        }
    }

    // 棋盘
    private class ChessBoard extends JPanel implements MouseListener {
        private static final long serialVersionUID = 1L;
        private int[][] chess = new int[15][15];  // 棋盘数组
        private int x, y;  // 当前下棋子的坐标

        public ChessBoard() {
            setBackground(new Color(245, 255, 250));
            addMouseListener(this);
        }

        // 重新开始游戏
        public void restart() {
            for (int i = 0; i < 15; i++) {
                for (int j = 0; j < 15; j++) {
                    chess[i][j] = 0;
                }
            }
            repaint();
        }

        // 绘制棋盘
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            for (int i = 0; i < 15; i++) {
                g.drawLine(20, 20 + i * 30, 440, 20 + i * 30);
            }
            for (int i = 0; i < 15; i++) {
                g.drawLine(20 + i * 30, 20, 20 + i * 30, 440);
            }
            for (int i = 0; i < 15; i++) {
                for (int j = 0; j < 15; j++) {
                    if (chess[i][j] == 1) {
                        g.setColor(Color.black);
                        g.fillOval(7 + i * 30, 7 + j * 30, 26, 26);
                    } else if (chess[i][j] == 2) {
                        g.setColor(Color.white);
                        g.fillOval(7 + i * 30, 7 + j * 30, 26, 26);
                    }
                }
            }
        }

        // 下棋
        public void mouseClicked(MouseEvent e) {
            if (isOver) {
                return;
            }
            x = e.getX();
            y = e.getY();
            if (x >= 20 && x <= 440 && y >= 20 && y <= 440) {
                int i = (x - 20) / 30;
                int j = (y - 20) / 30;
                if (chess[i][j] == 0) {
                    chess[i][j] = isBlack ? 1 : 2;
                    repaint();
                    if (isWin(i, j)) {
                        JOptionPane.showMessageDialog(null, (isBlack ? "黑" : "白") + "方获胜！");
                        isOver = true;
                        return;
                    }
                    isBlack = !isBlack;
                    label.setText((isBlack ? "黑" : "白") + "方下棋");
                }
            }
        }

        // 判断是否获胜
        public boolean isWin(int i, int j) {
            int count = 1;
            int color = chess[i][j];
            // 横向
            for (int k = i - 1; k >= 0; k--) {
                if (chess[k][j] == color) {
                    count++;
                } else {
                    break;
                }
            }
            for (int k = i + 1; k < 15; k++) {
                if (chess[k][j] == color) {
                    count++;
                } else {
                    break;
                }
            }
            if (count >= 5) {
                return true;
            }
            // 纵向
            count = 1;
            for (int k = j - 1; k >= 0; k--) {
                if (chess[i][k] == color) {
                    count++;
                } else {
                    break;
                }
            }
            for (int k = j + 1; k < 15; k++) {
                if (chess[i][k] == color) {
                    count++;
                } else {
                    break;
                }
            }
            if (count >= 5) {
                return true;
            }
            // 斜向
            count = 1;
            for (int k = i - 1, m = j - 1; k >= 0 && m >= 0; k--, m--) {
                if (chess[k][m] == color) {
                    count++;
                } else {
                    break;
                }
            }
            for (int k = i + 1, m = j + 1; k < 15 && m < 15; k++, m++) {
                if (chess[k][m] == color) {
                    count++;
                } else {
                    break;
                }
            }
            if (count >= 5) {
                return true;
            }
            // 反斜向
            count = 1;
            for (int k = i + 1, m = j - 1; k < 15 && m >= 0; k++, m--) {
                if (chess[k][m] == color) {
                    count++;
                } else {
                    break;
                }
            }
            for (int k = i - 1, m = j + 1; k >= 0 && m < 15; k--, m++) {
                if (chess[k][m] == color) {
                    count++;
                } else {
                    break;
                }
            }
            if (count >= 5) {
                return true;
            }
            return false;
        }

        public void mousePressed(MouseEvent e) {}
        public void mouseReleased(MouseEvent e) {}
        public void mouseEntered(MouseEvent e) {}
        public void mouseExited(MouseEvent e) {}
    }
}

规则说明：

1. 本游戏采用黑白对弈，黑方先行。
2. 棋盘为15x15的方格，黑子用黑色圆形表示，白子用白色圆形表示。
3. 玩家通过点击棋盘上的空白位置来下棋。
4. 每一方下完棋后，轮到对方下棋。
5. 当一方在横线、竖线、斜线上连续放置五个同色棋子时，即可获胜。
6. 若棋盘上已经没有空白位置，且没有一方达成获胜条件，游戏结束。