一、简单工厂代码

父类Car：

public class Car {
          
   
    public void CreateCar(){
          
   };
}

子类ElectricityCar：

public class ElectricityCar extends Car {
          
   

    @Override
    public void CreateCar() {
          
   
        System.out.println("生产电车");
    }
}

子类OilCar：

public class OilCar extends Car {
          
   

    @Override
    public void CreateCar() {
          
   
        System.out.println("生产油车");
    }
}

工厂类CarFactory：

public class CarFactory {
          
   
    public static Car createCar(String carType){
          
   
        Car car = null;
        switch (carType){
          
   
            case "ElectricityCar":
                car = new ElectricityCar();
                break;
            case "OilCar":
                car = new OilCar();
                break;
        }
        return car;
    }
}

主方法类main：

public class main {
          
   
    public static void main(String[] args) {
          
   
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要造的车的类型（ElectricityCar/OilCar）：");
        String type = sc.nextLine();
        Car car = null;
        car = CarFactory.createCar(type);
        car.CreateCar();
    }
}

执行结果：

二、简单工厂+反射

父类Car、子类ElectricityCar、子类OilCar同上，不做修改

修改后的工厂类CarFactory：

public class CarFactory {
          
   

    public Car createCar(String carType) throws InstantiationException, IllegalAccessException, ClassNotFoundException, IOException {
          
   
        return (Car) Class.forName("designpatterns.demo."+carType).newInstance();
    }
}

修改后的主方法类main：

public static void main(String[] args) throws ClassNotFoundException, IOException, InstantiationException, IllegalAccessException {
          
   
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要造的车的类型（ElectricityCar/OilCar）：");
        String type = sc.nextLine();
        //根据用户输入信息，创建具体车对象
        Car car = new designpatterns.demo.CarFactory().createCar(type);
        car.CreateCar();
    }

执行结果：