演员名单<&燃气轮机；Java中的重写内部类

我有一个类，它有一个我重写的内部类。这似乎很有效

class Car {
   public static class CarItems
   {
      public void doStuff(){ ... }
   }
}

class Honda extends Car {
   public static class CarItems extends Car.CarItems
   {
      @Override
      public void doStuff(){ ... }
   }
}

问题

这辆车在另一个我也要覆盖的类中：

class Dealership {
   //
   // #1: Here's a list of stuff, which includes car items
   //     as defined in parent class
   //
   protected List<CarAndStuff> carsAndStuff;

   public static class CarsAndStuff {
      private List<CarItems> carItems;
      private String name;
      // ...

      //
      // #2: This only returns the items from the rest of the
      //     clutter in this class
      //
      public List<CarItems> getCarsItems() { return carsItems; }
   }

   // As defined above
   public static class CarItems { ... }
}

class HondaDealership extends Dealership {
   //
   // #3: This sub-class only cares about the items
   //
   protected List<CarItems> carItems;

   public void extractItemsFromParent() {
      List<CarItems> _items = new ArrayList<CarItems>();

      for(CarsAndStuff stuff : carsAndStuff) {
         //
         // #4: So I try to extract the items, but using my
         //     overriden method. ERROR!
         //
         carItems.addAll(carsAndStuff.getCarItems());
      }

      this.carItems = carItems;
   }

   // As defined above
   public static class CarItems extends Car.CarItems { ... }
}

---

如果Honda.CarItems是一辆车，为什么不让我在列表中添加一个列表？？？

尝试让经销商CarItems系列使用泛型扩展功能。然后，在Hondadelership类中，您可以适当地铸造列表

因此，您的经销商类别将如下所示：

public class Dealership {
    //
    // #1: Here's a list of stuff, which includes car items
    // as defined in parent class
    //
    protected List<CarsAndStuff> carsAndStuff;

    public static class CarsAndStuff {
        private List<? extends CarItems> carItems;
        private String name;

        // ...

        //
        // #2: This only returns the items from the rest of the
        // clutter in this class
        //
        public List<? extends CarItems> getCarItems() {
            return carItems;
        }
    }

    // As defined above
    public static class CarItems {
        public void doStuff() {
        }
    }
}

public class HondaDealership extends Dealership {
    //
    // #3: This sub-class only cares about the items
    //
    protected List<CarItems> carItems;

    public void extractItemsFromParent() {
        List<CarItems> _items = new ArrayList<CarItems>();

        for (CarsAndStuff stuff : carsAndStuff) {
            //
            // #4: So I try to extract the items, but using my
            // overriden method. ERROR!
            //
            carItems.addAll((List<CarItems>) stuff.getCarItems());
        }

        this.carItems = carItems;
    }

    // As defined above
    public static class CarItems extends Dealership.CarItems {
        @Override
        public void doStuff() {
        }
    }
}

公共级经销商{
//
//#1：这是一张物品清单，包括汽车物品
//如父类中定义的
//
受保护的物品清单；
公共静态类CarsAndStuff{
私人列表这可能不是世界上最好的答案，但可以完成工作：

// Instead of addAll, add each item from CarsAndStuff.getCarItems
List<CarItems> _items = new ArrayList<CarItems>();

    for (CarsAndStuff stuff : carsAndStuff) {
        List<Car.CarItems> _carItems = stuff.getCarItems());
        for (CarItems _carItem: _carItems) {

            // ** Can't cast Car.CarItems ==> Honda.CarItems? Copy it! **
           _items.add(new CarItems(_carItem));

        }
    }

“这一切都很直截了当”…不完全是。在您的代码中，您试图将
列表添加到
列表中
。您不能这样做，因为
汽车.CarItems
不一定是
本田.CarItems
，更具体地说，
汽车.CarItems
不扩展
本田.CarItems
，而是反过来。因此，如果我添加项目f，这将起作用rom Honda，但如果我尝试在汽车实例中添加plain Car.CarItems，那是行不通的。我想我需要重新考虑我的设计。
// Instead of addAll, add each item from CarsAndStuff.getCarItems
List<CarItems> _items = new ArrayList<CarItems>();

    for (CarsAndStuff stuff : carsAndStuff) {
        List<Car.CarItems> _carItems = stuff.getCarItems());
        for (CarItems _carItem: _carItems) {

            // ** Can't cast Car.CarItems ==> Honda.CarItems? Copy it! **
           _items.add(new CarItems(_carItem));

        }
    }

class Honda extends Car {
  public static class CarItems extends Car.CarItems
  {

     public CarItems(Car.CarItems items) {
         this.property_1 = items.property_1;
         this.property_2 = items.property_2;
         this.property_3 = items.property_3;

         // etc.
     }

     @Override
     public void doStuff(){ ... }
  }
}