將Builder類暴露給客戶端代碼

Question

我將我的遊戲移動到其自己的包中，以使其在未來的遊戲中很有用。 我實現了一個建築商類的建議這裏的用戶的一個：Interfaces, static classes problem

public final class Builders { 
    public static Builder<? extends Sprite> newGameObjectBuilder(Point location, int drawable) { 
     return new GameObjectImpl.GameObjectBuilder(location, drawable); 
    } 
} 

現在的問題是，客戶端代碼不能使用助洗劑的方法（下文實施例）。我得到以下幾點：

"The method onReceiveKey(new Sprite.ReceiveKeys(){}) is undefined for the type Builder<capture#4-of ? extends Sprite>" 

基本上我不能使用公共靜態調用GameObjectBuilder內的任何方法。

onReceiveKey不起作用。只有Builder接口的build()方法可用。

public static Sprite newSoldier(int x, int y) { 
    return Builders.newGameObjectBuilder(new Point(x,y), R.drawable.soldier) 
    .onReceiveKey(new Sprite.ReceiveKeys() { 

     @Override 
     public void onKeyUp(int keyCode, Sprite self, Room room) { 


     } 

     @Override 
     public void onKeyDown(int keyCode, Sprite self, Room room) { 
      if(keyCode == KeyEvent.KEYCODE_DPAD_DOWN) { 
       self.moveY(room, 1, Direction.S); 
      } 
      else if(keyCode == KeyEvent.KEYCODE_DPAD_UP){ 
       self.moveY(room, -1, Direction.N); 
      } 
      else if(keyCode == KeyEvent.KEYCODE_DPAD_LEFT){ 
       self.moveX(room, -1,Direction.W); 
      } 
      else if(keyCode == KeyEvent.KEYCODE_DPAD_RIGHT){ 
       self.moveX(room, 1, Direction.E); 
      } 
     } 
    }) 
    .build(); 
} 

Answer 1

的事情是你的建設者就是這樣

public interface Builder<T> { 
    public T build(); 
} 

只是做

public interface SpriteBuilder<T extends Sprite> extends Builder<T> { 
    Builder<T> onReceiveKey(Sprite.ReceiveKeys receiver); 
} 

，改變建設者

public final class Builders { 
    public static SpriteBuilder newGameObjectBuilder(Point location, int drawable) { 
     return new GameObjectImpl.GameObjectBuilder(location, drawable); 
    } 
} 

和你GameObjectBuilder到

class GameObjectImpl extends AbstractSprite { 
    public static class GameObjectBuilder implements SpriteBuilder { 
    ... 
    } 
}