java图形化解决迷宫问题

不管怎么去解决迷宫问题，回溯法都是一个经典解法。
这里加了一个简单的图形界面。

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

public class Maze extends JApplet {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private Cell[][] board = new Cell[8][8];
    private JButton jbtFindPath = new JButton("Find Path");
    private JButton jbtClearPath = new JButton("Clear Path");
    private JPanel jpBoard, jpButton;
    private JLabel jlblStatus = new JLabel();

    public void init() {
        jpBoard = new JPanel();
        jpBoard.setLayout(new GridLayout(8, 8, 2, 2));

        jpButton = new JPanel();
        jpButton.setLayout(new FlowLayout());
        jpButton.add(jbtFindPath);
        jpButton.add(jbtClearPath);


        for (int row = 0; row < board.length; row++) {
            for (int col = 0; col < board[row].length; col++) {
                board[row][col] = new Cell();
                jpBoard.add(board[row][col]);
            }
        }


        setLayout(new BorderLayout());
        add(jlblStatus, BorderLayout.NORTH);
        add(jpBoard, BorderLayout.CENTER);
        add(jpButton, BorderLayout.SOUTH);


        jbtFindPath.addActionListener(new Listener());
        jbtClearPath.addActionListener(new Listener());
    }


    public static void main(String[] args) {

        JFrame frame = new JFrame("Maze");


       Maze applet = new Maze();


        frame.add(applet, BorderLayout.CENTER);


        applet.init();
        applet.start();


        frame.setSize(300, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    class Listener implements ActionListener {

        public void actionPerformed(ActionEvent e) {
            String arg = e.getActionCommand();
            if (e.getSource() instanceof JButton) {
                if ("Find Path".equals(arg)) {
                    findPath();
                } else if ("Clear Path".equals(arg)) {
                    clearPath();
                }
            }
        }
    }

    public void findPath() {
        if (findPath(0, 0)) {
            jlblStatus.setText("path found");
        } else {
            jlblStatus.setText("No path exists");
        }
    }

    public boolean findPath(int row, int col) {
        board[row][col].visit();

        if ((col == 7) && (row == 7)) {
            board[row][col].selectCell();
            return true;
        }

        if ((row > 0) && !board[row - 1][col].marked()
                && !board[row - 1][col].blocked() && !board[row - 1][col].visited()) {
            block(row, col);

            if (findPath(row - 1, col)) {
                board[row][col].selectCell();
                return true;
            }

            unblock(row, col);//没有路径，解除标记
        }

        if ((row < 7) && !board[row + 1][col].marked()
                && !board[row + 1][col].blocked() && !board[row + 1][col].visited()) {
            block(row, col);

            if (findPath(row + 1, col)) {
                board[row][col].selectCell();
                return true;
            }

            unblock(row, col);
        }

        if ((col > 0) && !board[row][col - 1].marked()
                && !board[row][col - 1].blocked() && !board[row][col - 1].visited()) {
            block(row, col);
            if (findPath(row, col - 1)) {
                board[row][col].selectCell();
                return true;
            }

            unblock(row, col);
        }

        if ((col < 7) && !board[row][col + 1].marked()
                && !board[row][col + 1].blocked() && !board[row][col + 1].visited()) {
            block(row, col);
            if (findPath(row, col + 1)) {
                board[row][col].selectCell();
                return true;
            }

            unblock(row, col);
        }

        return false;
    }


    //标记走过的路径
    public void block(int row, int col) {
        if (row > 0) {
            board[row - 1][col].block();
        }

        if (row < 7) {
            board[row + 1][col].block();
        }

        if (col > 0) {
            board[row][col - 1].block();
        }

        if (col < 7) {
            board[row][col + 1].block();
        }
    }


    public void unblock(int row, int col) {
        if (row > 0) {
            board[row - 1][col].unblock();
        }

        if (row < 7) {
            board[row + 1][col].unblock();
        }

        if (col > 0) {
            board[row][col - 1].unblock();
        }

        if (col < 7) {
            board[row][col + 1].unblock();
        }
    }

    public void clearPath() {
        for (int row = 0; row < board.length; row++) {
            for (int col = 0; col < board[row].length; col++) {
                board[row][col].deselectCell();
            }
        }
    }


    class Cell extends JPanel implements MouseListener {

        /**
         * 
         */
        private static final long serialVersionUID = 1L;
        private boolean marked = false;
        private boolean visited = false;
        private boolean blocked = false;
        public Cell() {
            setBackground(Color.white);
            addMouseListener(this);
        }

        public boolean marked() {
            return marked;
        }

        public void visit() {
            visited = true;
        }

        public boolean visited() {
            return visited;
        }

        public boolean blocked() {
            return blocked;
        }

        public void block() {
            blocked = true;
        }

        public void unblock() {
            blocked = false;
        }

        public void selectCell() {
            setBackground(Color.red);

            repaint();
        }

        public void deselectCell() {
            setBackground(Color.white);
            repaint();
        }

        public void paintComponent(Graphics g) {
            super.paintComponent(g);
//画叉
            if (marked) {
                g.drawLine(0, 0, getSize().width, getSize().height);
                g.drawLine(getSize().width, 0, 0, getSize().height);
            }
        }

        public void mouseClicked(MouseEvent e) {
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mouseExited(MouseEvent e) {
        }

        public void mouseReleased(MouseEvent e) {
        }

        public void mousePressed(MouseEvent e) {
            marked = !marked;
            repaint();
        }
    }
}