Java泛型调用构造函数

Question

假设我有四个类:Car、Convertible、PickupTruck 和 CarManufacturer。

Car 是Convertible 和PickupTruck 继承的抽象类:

public abstract class Car {
    private String name;
    private String colour;

    //Constructor
}

Convertible 和 PickupTruck 都有无参数构造函数:

public class Convertible extends Car {
    private boolean roofUnfolded;

    public Convertible() {
        super("Convertible", "Red");
        this.roofUnfolded = false;
    }
}

public class PickupTruck extends Car {
    private double capacity;

    public PickupTruck() {
        super("Pickup Truck", "Black");
        this.capacity = 100;
    }
}

CarManufacturer 存储 Convertibles 或 PickupTrucks 的列表。

public class CarManufacturer <T extends Car>{
    private List<T> carsProduced = new LinkedList<>();
}

如何实现调用无参数构造函数并将对象添加到列表中的函数 produceCar()？我试过:

public void produceCar(){
    this.carsProduced.add(new T());
}

返回错误:无法直接实例化类型参数'T'

Answer 1

这里解决了同样的问题: https://stackoverflow.com/a/36315051/7380270

关于这个问题，这是可行的:

public class CarManufacturer <T extends Car> {
    private Supplier<T> carType;
    private List<T> carsProduced = new LinkedList<>();

    public CarManufacturer(Supplier<T> carType) {
        this.carType = carType;
    }

    public void produceCar() {
        this.carsProduced.add(carType.get());
    }

}

public class Main {
    public static void main(String[] args) {
        CarManufacturer<Convertible> convertibleCarManufacturer = new CarManufacturer<>(Convertible::new);
        convertibleCarManufacturer.produceCar();
    }
}