Java 覆盖不同类型的类成员

Question

我有以下枚举:

public enum CarManufacturer {
    VOLKSWAGEN, CHEVROLET, DODGE, ...
}
public enum PlaneManufacturer {
    LOCKHEED, AIRBUS, BOEING, ...
}

和以下父类(super class):

public class Vehicle {
    int size;
    int weight;
    ...
}

我想做的是在车辆内部有一个明确的制造商，这样每个收到 Vehicle 类的人都知道它有一个制造商。

例如:

public class Vehicle {
    int size;
    int weight;
    int manufacturer;

    abstract int getManufacturer () {};
}

public class Plane extends Vehicle {
    PlaneManufacturer manufacturer;
    PlaneManufacturer getManufacturer () { return this.manufacturer; }
    ...
}
public class Car extends Vehicle {
    CarManufacturer manufacturer;
    CarManufacturer getManufacturer () { return this.manufacturer; }
    ...
}

执行此操作的最佳方法是什么？

Answer 1

创建一个 Manufacturer 接口(interface)，并让您的枚举实现该接口(interface)。

public interface Manufacturer {}

public enum CarManufacturer implements Manufacturer {
    VOLKSWAGEN, CHEVROLET, DODGE, ...
}
public enum PlaneManufacturer implements Manufacturer {
    LOCKHEED, AIRBUS, BOEING, ...
}

然后在您的 Vehicle 类中，您可以:

public class Vehicle {
    int size;
    int weight;
    Manufacturer manufacturer;

    Manufacturer getManufacturer () {
        return manufacturer;
    };
}