Java设计模式—享元（FlyWeight）模式

public abstract class Piece {
    protected PieceColor m_color;
    protected PiecePos m_pos;
 
    public Piece(PieceColor color ,PiecePos pos){
        m_color = color;
        m_pos = pos;
    }
 
    public abstract void draw() ;
}

public class WhitePiece extends Piece{
    public WhitePiece(PieceColor color ,PiecePos pos){
        super(color , pos);
    }
 
    @Override
    public void draw() {
        System.out.println("draw a whitePiece ! ");
    }
}

public class BlackPiece extends Piece {
    public BlackPiece(PieceColor color , PiecePos pos){
        super(color,pos);
    }
 
    @Override
    public void draw() {
        System.out.println("draw a blackPiece !");
    }
}

public enum PieceColor {
    BLACK,
    WHITE
}

public class PieceBoard {
    private static final ArrayList m_arrayPiece = new ArrayList<>();
 
    private String m_blackName;
    private String m_whiteName;
 
    public PieceBoard(String black , String white){
        m_blackName = black;
        m_whiteName = white;
    }
 
    public void SetPiece(PieceColor color ,PiecePos pos){
        Piece piece = null;
        if(color == PieceColor.BLACK){
            piece = new BlackPiece(color, pos);
            System.out.println(m_blackName + "在位置(" +
                    pos.getX() + ","+pos.getY() + ")");
            piece.draw();
        }else {
            piece = new WhitePiece(color, pos);
            System.out.println(m_whiteName + "在位置(" +
                    pos.getX() + "," +pos.getY() +")");
            piece.draw();
        }
        m_arrayPiece.add(piece);
    }
 
 
    public static void main(String[] args) {
        PieceBoard board = new PieceBoard("Black Player", "White Player");
        PiecePos pos = new PiecePos(3, 4);
        board.SetPiece(PieceColor.BLACK, pos);
    }
}