java - parent - 汽车。子类: Electric or Fossil. child :私家车或出租车

Question

我最近开始学习 OOP，这让我很困惑。我想制作 super 汽车和电动或化石汽车作为其子类。

`abstract class Electric extends Car`. 

问题是我只想创建 Private 或 Taxi 的实例。我该如何构建它，以便理想情况下允许我发表声明

Taxi cab1 = new Fossil()

我意识到这是一个答案显而易见的问题，但是在看了泛型和接口(interface)直到我眼睛发酸之后，挫败感一直在增长。

如果有人能提醒我如何做到这一点，我将不胜感激，因为我肯定我已经知道但后来忘记了。

Answer 1

你是这样想的吗？

汽车类别:

public class Car{

private int yearOfManufacture;
private String brand;
private String model;
private Engine engine;  

public Car(String pBrand, String pModel, int pYearOfManufacture, Engine pEngine){
    this.yearOfManufacture = pYearOfManufacture;
    this.brand = pBrand;
    this.model = pModel;
    this.engine = pEngine;
}

}

引擎等级:

public class Engine {

 private int power;
 private int emission;

 public Engine(int power, int emission) {
  this.power = power;
  this.emission = emission;
 }
}

IC 引擎类:

public class ICEngine extends Engine {

 private int numOfValves;

 public ICEngine(int power, int emission, int numOfValves) {
  super(int power, int emission);
  this.numOfValves = numOfValves;
 }
}

电机类:

public class ElectricEngine extends Engine {

 private int wattage;

 public ICEngine(int power, int emission, int wattage) {
  super(int power, int emission);
  this.wattage = wattage;
 }
}

出租车类:

public class Taxi extends Car{

    private String driverName;

    public Taxi(String driverName, String pBrand, String pModel, int pYearOfManufacture, Engine engine){
        super(pBrand, pModel, pYearOfManufacture, engine);
        this.driverName = driverName;
    }
}

私家车类:

public class PrivateCar extends Car {

 private String ownerName;

 public PrivateCar(String ownerName, String pBrand, String pModel, int pYearOfManufacture, Engine engine) {
  super(pBrand, pModel, pYearOfManufacture, engine);
  this.ownerName = ownerName;
 }


}

使用应用程序类:

public class MyApp {

 public static void main(String[] args) {

  Engine eEngine1 = new ElectricEngine(100, 10, 10000);
  Car myElectricTaxi = new Taxi("Driver1", "Honda", "Accord", 2013, eEngine1);

  Engine icEngine1 = new ICEngine(100, 10, 6);
  Car myICTaxi = new Taxi("Driver2", "Honda", "Accord", 2013, icEngine1);

  Engine eEngine2 = new ElectricEngine(100, 10, 10000);
  Car myElectricPrivateCar = new PrivateCar("Owner1", "Honda", "Accord", 2013, eEngine2);

  Engine icEngine2 = new ICEngine(100, 10, 4);
  Car myICPrivateCar = new PrivateCar("Owner2", "Honda", "Accord", 2013, icEngine2);

 }

}