java - 泛型 java 类中的反射

Question

我有以下类(class)(这只是一个简化的例子):

public abstract class Material {
    public abstract String name();
    /* ... */
}

public class Wood extends Material {
    @Override
    public String name() {
        return "<WOOD>";
    }
    /* ... */
}

public class Metal extends Material {
    @Override
    public String name() {
        return "{Metal}";
    }
    /* ... */
}

public class Car<T extends Material> {
    public void printName() {
        System.out.println(T.name()); // Here is the problem!
    }
    /* ... */
}

public class Main {
    public static void main(String[] args) {
        Car<Wood> myCar1 = new Car<Wood>();
        Car<Metal> myCar2 = new Car<Metal>();
        myCar1.printName();
        myCar1.printName();
    }
}

问题在代码中指出。

Answer 1

这可能是我实现它的方式。对于你的情况是否令人满意，我不知道。

enum Material {

    WOOD("<WOOD>"),
    METAL("{Metal}");

    String name;
    private Material(String name) {
        this.name = name;
    }
    public String toString() {
        return name;
    }
}

class Car {
    Material material;
    public Car(Material material) {
        this.material = material;
    }
    public void printName() {
        System.out.println(material);
    }
}

public class Main {
    public static void main(String[] args) {
        Car myCar1 = new Car(Material.WOOD);
        Car myCar2 = new Car(Material.METAL);
        myCar1.printName();
        myCar2.printName();
    }
}