First of all, your code iterates through a board and generates random marks of X and O. This leads to some very odd board states, being always filled row-by-row, and possibly with unbalanced number of X and O marks.
IMHO you should organize your code in opposite manner to fill a board similary to a true game. I mean a series of 9 marks 'XOXOXOXOX' spreaded over the board.
Let Labels labels
be a nine-character array, initialized to 9 spaces.
public int doGame( Labels labels)
{
labels = " ";
int itisXmove = true; // player X or O turn
for( int movesLeft = 9; movesLeft > 0; movesLeft --)
{
int position = // 0 .. movesLeft-1
(int) Math.floor(Math.random() * movesLeft);
for( int pos = 0; pos < 9; pos ++) // find position
if( labels[ pos] == " ") // unused pos?
if( position-- == 0) // countdown
{
if( itisXmove) // use the pos
labels[ pos] = "X"; // for current player
else
labels[ pos] = "O";
break;
}
int result = checkWinner( labels); // who wins (non-zero)?
if( result != 0)
return result;
itisXmove = ! itisXmove; // next turn
}
return 0; // a tie
}
then
public void actionPerformed(ActionEvent e)
{
Labels labels;
int result = doGame( labels);
if( result == valueForX)
JOptionPane.showMessageDialog(null, "X is the Winner!");
else if( result == valueForO)
JOptionPane.showMessageDialog(null, "O is the Winner!");
else
JOptionPane.showMessageDialog(null, "It's a tie!");
for( int rowpos = 0; rowpos < 9; rowpos += 3)
{
for( int colpos = 0; colpos < 3; colpos ++)
/* output (char)label[ rowpos + colpos] */;
/* output (char)newline */;
}
}