Basic Tic Tac Toe programming help please

Question

I'm trying to make a seperate java class(there is another main that calls this using SWING interface) that makes mark on the board.
It's supposed to do the following
Method makeMark returns:
a null if the cell indicated by row and column has already been marked
an X if it is X's turn (X gets to go first)
a Y if it is Y's turn
Thus makeMark will have to keep of marks made previously and return the appropriate string
for the requested cell.
and here is what I got so far, but only getting empty clicks as a respond. Any help will be appreciated. thanks.
import javax.swing.JButton;
public class TicTacToeGame {
     public String makeMark(int row, int column){
String player = "X";
String [][] Enum = new String [3][3];
          for (row=0; row<=2; row++){
               for (column=0; column<=2; column++)
                    if (Enum[row][column] == "")
if (player == "X"){
Enum[row][column] = "X";
player = "Y";
return "X";
if (player == "Y"){
Enum[row][column] = "O";
player = "X";
return "Y";
else
return null;
          return player;
}

Answer 1

ok is there a simpler codes that will just flip-flop between X and O? I had it working before but somehow it's not working anymore. Before I had
public String makeMark(int row, int column){
player = "X";
if (player = "X")
player = "O";
else if (player = "O")
player = "X";
or soemthing like this but it used to work, but I had to revise the code to do more things and it stopped even flip-flopping between X and O.
Here's main code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
* This class is the GUI for TicTacToe. It only handles user clicks on
* buttons, which represent X's and O's
* @author Hal Mendoza
* CSE 21 - Jan 18, 2011, 8:18:22 PM
* TicTacToe.java
public class TicTacToe extends JPanel implements ActionListener {
public final static int NUM_ROWS_COLUMNS = 3;
private JButton arrayofButtons[][] = new JButton[NUM_ROWS_COLUMNS][NUM_ROWS_COLUMNS];
TicTacToeGame board = new TicTacToeGame();
public TicTacToe() {
     BoxLayout ourLayout = new BoxLayout(this, BoxLayout.Y_AXIS);
     setLayout(ourLayout);
     add(buildMainPanel());
* Builds the panel with buttons
* @return the panel with buttons
private JPanel buildMainPanel() {
     JPanel panel = new JPanel();
     GridLayout gridLayout = new GridLayout(0, NUM_ROWS_COLUMNS);
     panel.setLayout(gridLayout);
     for (int row = 0; row < arrayofButtons.length; ++row)
          for (int column = 0; column < arrayofButtons[0].length; ++column) {
               arrayofButtons[row][column] = new JButton();
               arrayofButtons[row][column].setPreferredSize(new Dimension(50, 50));
               arrayofButtons[row][column].addActionListener(this);
               // Use actionCommand to store x,y location of button
               arrayofButtons[row][column].setActionCommand(Integer.toString(row) + " " +
                         Integer.toString(column));
               panel.add(arrayofButtons[row][column]);
     return panel;
* Called when user clicks buttons with ActionListeners.
public void actionPerformed(ActionEvent e) {
     JButton button = (JButton) e.getSource();
     String xORo;
     String rowColumn[] = button.getActionCommand().split(" ");
     int row = Integer.parseInt(rowColumn[0]);
     int column = Integer.parseInt(rowColumn[1]);
     xORo = board.makeMark(row, column);
     if (xORo != null)
          button.setText(xORo);
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event dispatch thread.
private static void createAndShowGUI() {
     // Create and set up the window.
     JFrame frame = new JFrame("Tic Tac Toe");
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     // Add contents to the window.
     frame.add(new TicTacToe());
     // Display the window.
     frame.pack();
     frame.setVisible(true);
public static void main(String[] args) {
     // Schedule a job for the event-dispatching thread:
     // creating and showing this application's GUI.
     javax.swing.SwingUtilities.invokeLater(new Runnable() {
          public void run() {
               createAndShowGUI();
}