多态的记录

public abstract class Car {

    public abstract String getCarName();

}

public class BYD extends Car {

    @Override
    public String getCarName() {
        return "比亚迪";
    }

}

public class JL extends Car {

    @Override
    public String getCarName() {
        return "吉利";
    }

}

public class CarFactory {

    public static Car getCarName(String name) {
        Car car = null;
        switch (name) {
        case "BYD":
            car = new BYD();
            break;
        case "JL":
            car = new JL();
            break;
        default:
            break;
        }
        return car;
    }
}

public class CarTest {

    public static void main(String[] args) {
        Car byd = CarFactory.getCarName("BYD");
        System.out.println(byd.getCarName());
        Car jl = CarFactory.getCarName("JL");
        System.out.println(jl.getCarName());
    }
}

输出信息：

比亚迪
吉利