Simple game code, TICTACTOE grid change, Java

Here is a simple game code also known as TicTacToe. It goes to GUI and gives cells with X or O -s. What I want to do is to change each array element (or each tile/cell in GUI) to numbers from 1 to 9 (with different colours and so on, but that's nit the issue, I can handle later). There are only two options in the code - X and O (as it is TicTacToe). I guess I need to change/add something related to token, but how and what - have no idea, since I just started. Literally, few days. No kidding. So how to make numbered tiles instead and would it possible to make it without changing the approach in this example?

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

/**
* JFrame to hold TicTacToe board.
*/
public class TicTacToeFrame extends JFrame
{
   // Indicate whose turn it is
   private char whoseTurn = 'X';
   private boolean gameOver = false;

   // Create cell grid
   private Cell[][] cells = new Cell[3][3];

   // Create a status label
   JLabel jlblStatus = new JLabel("X's turn to play");

   /**
    * No-argument Constructor
    */
   public TicTacToeFrame()
   {
       // Panel to hold cells
       JPanel panel = new JPanel(new GridLayout(3, 3, 0, 0));
       for (int i = 0; i < 3; i++)
           for (int j = 0; j < 3; j++)
               panel.add(cells[i][j] = new Cell());

       panel.setBorder(new LineBorder(Color.red, 1));
       jlblStatus.setBorder(new LineBorder(Color.yellow, 1));

       add(panel, BorderLayout.CENTER);
       add(jlblStatus, BorderLayout.SOUTH);
   }

   /**
    * Determine if game board is full.
    * @return True, if game board is full. Otherwise, false.
    */
    public boolean isFull()
    {
       for (int i = 0; i < 3; i++)
           for (int j = 0; j < 3; j++)
               if (cells[i][j].getToken() == ' ')
                   return false;
       return true;
    }



/**
    * Determines if a given token has won.
    * @param token Token to test for winning
    * @return True, if the token has won. Otherwise, false.
    */
   public boolean isWon(char token)
   {
       // check rows
       for (int i = 0; i < 3; i++)
           if ((cells[i][0].getToken() == token)
                   && (cells[i][1].getToken() == token)
                   && (cells[i][2].getToken() == token)) 
           {
               return true;
           }

       // check columns
       for (int j = 0; j < 3; j++)
           if ((cells[0][j].getToken() == token)
               && (cells[1][j].getToken() == token)
               && (cells[2][j].getToken() == token))
           {
               return true;
           }
       // check diagonal
       if ((cells[0][0].getToken() == token)
               && (cells[1][1].getToken() == token)
               && (cells[2][2].getToken() == token))
           {
               return true;
           }

       if ((cells[0][2].getToken() == token)
               && (cells[1][1].getToken() == token)
               && (cells[2][0].getToken() == token))
           {
               return true;
           }

       return false;
   }

    /**
    * Defines a cell in a TicTacToe game board.
    */
    public class Cell extends JPanel
    {
       // token of this cell
       private char token = ' ';

       /**
        * Constructor
        */
       public Cell()
       {
           setBorder(new LineBorder(Color.black, 1));
           addMouseListener(new MyMouseListener());
       }


    /**
        * Gets the token of the cell.
        * @return The token value of the cell.
        */
       public char getToken()
       {
           return token;
       }

       /**
        * Sets the token of the cell.
        * @param c Character to use as token value.
        */
       public void setToken(char c)
       {
           token = c;
           repaint();
       }

       @Override
       protected void paintComponent(Graphics g)
       {
           super.paintComponent(g);

           if (token == 'X')
           {
               g.drawLine(10, 10, getWidth() - 10, getHeight() - 10);
               g.drawLine(getWidth() - 10, 10, 10, getHeight() - 10);
           }

           else if (token == 'O')
           {
               g.drawOval(10, 10, getWidth() - 20, getHeight() - 20);
           }
       }

       private class MyMouseListener extends MouseAdapter
       {
           @Override
           public void mouseClicked(MouseEvent e)
           {
               if (gameOver)
                   return;

               // if the cell is empty and the game is not over
               if (token == ' ' && whoseTurn != ' ')
                   setToken(whoseTurn);

               // Check game status
               if (isWon(whoseTurn))
               {
                   jlblStatus.setText(whoseTurn + " won! Game over!");
                   whoseTurn = ' ';
                   gameOver = true;
               }
               else if (isFull())
               {
                   jlblStatus.setText("Tie game! Game over!");
                   whoseTurn = ' ';
                   gameOver = true;
               }
               else
               {
                   whoseTurn = (whoseTurn == 'X') ? 'O' : 'X';
                   jlblStatus.setText(whoseTurn + "'s turn.");
               }
           }
       } // end class MyMouseListener
    } // end class Cell
} // end class TicTacToeFrame

Here is the MainClass

import javax.swing.JFrame;

public class TicTacToe 
{
    public static void main(String[] args) 
    {
        JFrame ticTacToe = new TicTacToeFrame();
        ticTacToe.setTitle(TicTacToe Game");
        ticTacToe.setSize(600, 600);
        ticTacToe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        ticTacToe.setLocationRelativeTo(null);
        ticTacToe.setVisible(true);
    }
} // end class TicTacToe