tic-tac-toe/src/Main.java

public class Main {
    public static void main(String[] args) {
        PlayField field = new PlayField();
        try(ConsoleReader cr = new ConsoleReader()) {
            do {
                doGame(cr, field);
            } while(askPlayAgain(cr, field));
        }
    }

    public static void doGame(ConsoleReader cr, PlayField field) {
        while(true) {
            int nextPos = getPlayerTurn(cr, field);

            field.setPos(nextPos, 1);
            field.print();
            if(hasGameEnded(field, 1)) {
                break;
            }

            // Opponent's turn
            System.out.println("Opponents turn:");
            field.oppMove();
            field.print();
            if(hasGameEnded(field, 2)) {
                break;
            }
        }
    }

    public static boolean hasGameEnded(PlayField field, int player) {
        if(field.hasWon(player)) {
            printWinner(player);
            return true;
        }
        if(field.isDraw()) {
            System.out.println("Draw.");
            return true;
        }
        return false;
    }

    public static int getPlayerTurn(ConsoleReader cr, PlayField field) {
        String s = "Where do you want to set your 'x'? (1-9)";
        while(true) {
            System.out.println(s);
            int nextPos = cr.readInt(s) - 1;
            if(nextPos >= 0 && nextPos <= 8 && field.isFree(nextPos)) {
                return nextPos;
            }
        }
    }

    public static void printWinner(int player) {
        if(player == 1) {
            System.out.println("Player 'x' has won.");
        } else {
            System.out.println("Player 'o' has won.");
        }
    }

    private static boolean askPlayAgain(ConsoleReader cr, PlayField field) {
        while(true) {
            System.out.println("New game? Y/N");
            String s = cr.readLine();
            if(s.equals("Y")) {
                field.reset();
                return true;
            } else if(s.equals("N")) {
                System.out.println("Game closed.");
                return false;
            }
        }
    }
}