run sub-class help?

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

public class TTT extends JFrame implements ActionListener { //DO NOT TOUCH!!!

    //makes the array for the buttons
    JButton spots[ ] = new JButton[ 9];
    //keeps track of who's turn it is
    int turn = 0;
    //lets it go again
    boolean go = true;
    //gets the images for the X's and O's
    ImageIcon red = new ImageIcon("x.PNG");
    ImageIcon blue = new ImageIcon("o.PNG");
    ImageIcon blank = new ImageIcon("blank.PNG");

    public static void main (String []args ) {
        TTT frame = new TTT(); //DO NOT TOUCH!!!
        frame.setVisible(true);
    }

    public TTT( ) { //DO NOT TOUCH!!!
        //set the frame default properties
        setTitle ("Tic Tac Toe");
        setSize ( 308, 308 );
        setLocationRelativeTo ( null );
        setResizable(false);
        //register 'Exit upon closing' as a default close operation
        setDefaultCloseOperation( EXIT_ON_CLOSE );

        changeBkColor( );
    }

    private void changeBkColor() {
        while (go) {
            //declares some variables that we will use later
            int newLine = 0;
            int lineCount = 0;
            //change background color to white
            Container contentPane = getContentPane();
            contentPane.setBackground(Color.WHITE);
            contentPane.setLayout(null);
            //puts the buttons on the screen
            for (int i = 0; i < spots.length; i++) {
                //make it first appear as a blank image
                spots[ i] = new JButton (blank);
                //checks if it needs a new row
                if (i == 3 || i == 6) {
                    newLine++;
                    lineCount = 0;
                }
                //sets the positions of the buttons
                spots[ i].setBounds(lineCount*100, newLine*100, 100, 100);
                //add it to the container
                contentPane.add(spots[ i]);
                spots[ i].addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent e) {
                        public void run() {
                            //check button pressed
                            for (int i = 0; i < spots.length; i++) {
                                if(e.getSource()==spots[ i]) {
                                    //check turn
                                    if (turn%2==0) {
                                        spots[ i].setIcon(red);
                                    } else {
                                    spots[ i].setIcon(blue);
                                    }
                                    //disable the button so it can't be re-pressed
                                    spots[ i].removeActionListener(this);
                                }
                            }
                            turn++;
                            //checks for wins
                            for(int i = 0; i < 3; i++) {
                                if (spots[ i].getIcon()==red &&                //checks for verticle x win
                                    spots[ i+3].getIcon()==red &&
                                    spots[ i+6].getIcon()==red) {
                                        int again1 = JOptionPane.showConfirmDialog(null, "X Wins! Do you want to play again?", "Play again?", JOptionPane.YES_NO_OPTION);
                                        if (again1 == JOptionPane.YES_OPTION) {
                                            go = true;
                                        } if (again1 == JOptionPane.NO_OPTION) {
                                            JOptionPane.showMessageDialog(null, "Okay then. Bye!");
                                            go = false;
                                        }
                                }else if (spots[ i].getIcon()==blue &&     //checks for verticle o win
                                            spots[ i+3].getIcon()==blue &&
                                            spots[ i+6].getIcon()==blue) {
                                                int again2 = JOptionPane.showConfirmDialog(null, "O Wins! Do you want to play again?", "Play again?", JOptionPane.YES_NO_OPTION);
                                                if (again2 == JOptionPane.YES_OPTION) {
                                                    go = true;
                                                } if (again2 == JOptionPane.NO_OPTION) {
                                                    JOptionPane.showMessageDialog(null, "Okay then. Bye!");
                                                    go = false;
                                                }
                                }else if (spots[ i*3].getIcon()==red &&    //checks for horizontal x win
                                            spots[ (i*3)+1].getIcon()==red &&
                                            spots[ (i*3)+2].getIcon()==red) {
                                                int again3 = JOptionPane.showConfirmDialog(null, "X Wins! Do you want to play again?", "Play again?", JOptionPane.YES_NO_OPTION);
                                                if (again3 == JOptionPane.YES_OPTION) {
                                                    go = true;
                                                } if (again3 == JOptionPane.NO_OPTION) {
                                                    JOptionPane.showMessageDialog(null, "Okay then. Bye!");
                                                    go = false;
                                                }
                                }else if (spots[ i*3].getIcon()==blue &&   //checks for horizontal o win
                                            spots[ (i*3)+1].getIcon()==blue &&
                                            spots[ (i*3)+2].getIcon()==blue) {
                                                int again4 = JOptionPane.showConfirmDialog(null, "O Wins! Do you want to play again?", "Play again?", JOptionPane.YES_NO_OPTION);
                                                if (again4 == JOptionPane.YES_OPTION) {
                                                    go = true;
                                                } if (again4 == JOptionPane.NO_OPTION) {
                                                    JOptionPane.showMessageDialog(null, "Okay then. Bye!");
                                                    go = false;
                                                }
                                }else if (spots[ i].getIcon()==red &&      //checks for diagnol x win
                                            spots[ 4].getIcon()==red &&
                                            spots[ 8-i].getIcon()==red) {
                                                int again5 = JOptionPane.showConfirmDialog(null, "X Wins! Do you want to play again?", "Play again?", JOptionPane.YES_NO_OPTION);
                                                if (again5 == JOptionPane.YES_OPTION) {
                                                    go = true;
                                                } if (again5 == JOptionPane.NO_OPTION) {
                                                    JOptionPane.showMessageDialog(null, "Okay then. Bye!");
                                                    go = false;
                                                }
                                }else if (spots[ i].getIcon()==blue &&    //checks for diagnol o win
                                            spots[ 4].getIcon()==blue &&
                                            spots[ 8-i].getIcon()==blue) {
                                                int again6 = JOptionPane.showConfirmDialog(null, "O Wins! Do you want to play again?", "Play again?", JOptionPane.YES_NO_OPTION);
                                                if (again6 == JOptionPane.YES_OPTION) {
                                                    go = true;
                                                } if (again6 == JOptionPane.NO_OPTION) {
                                                    JOptionPane.showMessageDialog(null, "Okay then. Bye!");
                                                    go = false;
                                                }
                                }
                            }
                            lineCount++;
                        }
                    }
                });
            }
        } if (!go) {
            System.exit(0);
        }
    }
}