Mini Juego en Java - Tic Tac Toe - Triqui

Mini juego Tic-Tac-Toe o Triqui, programado en Java. La continuacion esta en el primer comentario.

public class Main {

    public static void main(String[] args) {
        TicTacToe newGame = new TicTacToe();
        newGame.startTicTacToeGame();
    }
}

public class TicTacToe {

    final char DASH = '-';
    final char PLEAT = '|';
    final char SPACE = ' ';
    final char OU = 'O';
    final char EX = 'X';
    final int COLS = 8;
    final int ROWS = 4;
    final int TWO = 2;
    final Scanner scanner = new Scanner(System.in);
    final List<Integer> indexCol = List.of(2, 4, 6);
    final List<Integer> indexRow = List.of(1, 2, 3);

    List<List<Character>> boardList;
    boolean firstPlayer = true;

    public void startTicTacToeGame() {
        boolean endGame = false;
        boardList = createEmptyBoard();
        printGameBoard(boardList);
        do {
            List<String> coordinates = getCoordinates();
            if (checkCoordinates(coordinates)) {
                printGameBoard(boardList);
                if (checkGame(boardList)) {
                    endGame = true;
                } else {
                    firstPlayer = !firstPlayer;
                }
            }
        } while (!endGame);
    }

    private List<List<Character>> createEmptyBoard() {
        List<List<Character>> boardList = new ArrayList<>();
        for (int i = 0; i <= ROWS; i++) {
            List<Character> listRow = new ArrayList<>();
            for (int j = 0; j <= COLS; j++) {
                if (i == 0 || i == ROWS) {
                    listRow.add(DASH);
                } else if (j == 0 || j == COLS) {
                    listRow.add(PLEAT);
                } else {
                    listRow.add(SPACE);
                }
            }
            boardList.add(listRow);
        }
        return boardList;
    }

    private boolean checkGame(List<List<Character>> boardList) {
        boolean endGame = false;
        List<Character> vertical = findVerticalGame(boardList);
        List<Character> horizontal = findHorizontalGame(boardList);
        char diagonal = findDiagonalGame(boardList);
        boolean empty = findEmptySpace(boardList);

        boolean winner = vertical.size() == TWO || horizontal.size() == TWO || diagonal != SPACE;
        boolean twoGames = vertical.size() > TWO || horizontal.size() > TWO;

        if (winner) {
            char winnerChar = diagonal;
            if (vertical.size() == TWO) {
                winnerChar = vertical.get(1);
            } else if (horizontal.size() == TWO) {
                winnerChar = horizontal.get(1);
            }
            System.out.println(winnerChar + " wins");
            endGame = true;
        } else if (twoGames || !empty) {
            System.out.println("Draw");
            endGame = true;
        }
        return endGame;
    }

    private List<String> getCoordinates() {
        System.out.print("Enter the coordinates: ");
        return List.of(scanner.nextLine().split(" "));
    }

    private boolean checkCoordinates(List<String> coordinates) {
        int numX;
        int numY;
        boolean validCoord = false;
        List<Integer> converted = convertCoordinatesToInteger(coordinates);
        if (!converted.isEmpty()) {
            numX = converted.get(0);
            numY = converted.get(1);
            if (indexRow.contains(numX) && numY >= 1 && numY <= 3) {
                numY = indexCol.get(numY - 1);
                if (boardList.get(numX).get(numY) == SPACE) {
                    setPlayInBoardList(numX, numY);
                    validCoord = true;
                } else {
                    System.out.println("This cell is occupied! Choose another one!");
                }
            } else {
                System.out.println("Coordinates should be from 1 to 3!");
            }
        } else {
            System.out.println("You Should enter numbers!");
        }
        return validCoord;
    }

    private List<Integer> convertCoordinatesToInteger(List<String> coordinates) {
        List<Integer> numbers = new ArrayList<>();
        try {
            numbers.add(Integer.parseInt(coordinates.get(0)));
            numbers.add(Integer.parseInt(coordinates.get(1)));
        } catch (Exception ignored) {}
        return numbers.size() == TWO ? numbers : new ArrayList<>();
    }

    // continua...