Design Chess - Object Oriented Design

Question

I am trying to design online chess game(figuring out required classes). Need some suggestion on choosing better option to validate the move. So, lets say, I have below class

Option 1 : My Initial thought process was to have a validator Factory defined, and set of validators specific to each piece.

Public class Game{
    private String id;
    private Player player1;
    private Player player2;
    private GameStatus status;
    private Board board;
    private Color currentTurn ; //who have to make move now?

    private static Map<PieceType , List<IValidate>> validators; 

    static {
        validators = initialize_the_appropriate_validators
    }

    public boolean makeMove(Move move){

        PieceType type = move.getPiece().getType() ;

        for(Ivalidate validator : validators.get(type)){
                if(!validator.validate())
                    throw new InvalidMoveException("Move not allowed!");
        }

        .............
    }
}

 public class KnightMovesValidator implements Ivalidate{
     public boolean validate(Move){
          //TODO: vlidate if it is proper move based on the piece
     }
 }

public class Box{
    private int x ;
    private int y ;
    private Piece piece;

}

public Board{
    private Box [][] boxes;
}

public class Move{
    private Box src;
    private Box dest;
    private Piece piece;
    private Player player;
}

 public enum PieceType{
    KINGHT , ROOK , KING , QUEEN .......
 }

 public enum color{
    BLACK,WHITE
 }

 public class Piece{
    private PieceType type;
    private Color color;
    private boolean isKilled;
 }

---

Option 2 : When I searched on the internet to validate my implementation. I found the below design in many places.

 Public Knight extends Piece{

        public boolean canMove(Box src , Box dest) {
           //TODO : implement   
        }
 }

The idea is, instead of having external validator. Each piece is saying whether the requested move is possible or not. It sounds better than my design to me. But still I have some question here... Box is aware of the class Piece because it is holding it.
Should Piece be aware of Box(its location) ?? Shouldn't piece be independent of Box?

Is this correct way of designing our POJO? What is the thought process behind it? Please throw me some light.

Thanks.

Answer 1

If you want to really practice object-orientation here is a completely easy rule to follow:

Don't have getters!

This will force your design to assign real responsibilities to things, you will almost certainly automatically follow the Law of Demeter, Tell don't ask, and other important principles of object-orientation.

Don't let people tell you that things can't have behavior because they are inanimate. In object-orientation all things live. Every object has behavior, privacy and does its own things. It is desirable to anthropomorphize things in object-orientation.

Your design at this point is very far from this, so you'll have quite a bit of work to do, but if you manage to pull it off without cheating (there are ways to cheat this rule :), you'll have an experience with object-orientation that quite frankly not a lot of people have.