java - 与类共享字段方法

Question

我有一个包含对象的类现在我想从 Container 类外部调用 Box 和 Toy 对象的函数

class Container
{
   Box box1 = new Box();
   Toy toy1 = new Toy();
   public void open()
   {
      box1.open();
   }
   public void play()
   {
      toy1.play();
   }
}

如何避免重新创建方法并仅与 Container 类共享方法。我无法使用继承，因为我有 2 个或更多对象。

Answer 1

您可以按如下方式进行操作。

public interface ToyInterface {
    public void play();
}

public class Toy implements ToyInterface {
    @Override
    public void play() {
        System.out.println("Play toy");
    }
}

public interface BoxInterface {
    public void open();
}

public class Box implements BoxInterface {
    @Override
    public void open() {
        System.out.println("open box");
    }
}

public class Container implements ToyInterface, BoxInterface {
    private BoxInterface box;
    private ToyInterface toy;

    public Container() {
        box = new Box();
        toy = new Toy();
    }

    public BoxInterface getBox() {
        return box;
    }

    public ToyInterface getToy() {
        return toy;
    }

    @Override
    public void play() {
        System.out.println("play container");
        this.toy.play();
    }

    @Override
    public void open() {
        System.out.println("open container");
        this.box.open();
    }
}

然后就可以在Container之外访问Box和Toy类的方法了。

Container container = new Container();
container.open();
container.getBox().open();

container.play();
container.getToy().play();