【JAVA小白】 第一次寫接口，出現(xiàn)未知錯(cuò)誤。

代碼如下：

abstract class Animal {
    int age;
    public Animal() {};
    public Animal(int age) {
        this.age = age;
    }
}

class Bird extends Animal implements Fly {
    public Bird(int age) {
        super(age);
        System.out.println("我是一直紅色的鳥！");
        System.out.println("我今年" + age + "歲了！");
        }
    }
    public void service() {
        System.out.println("飛起來(lái)了！");
    }
}

class Fish extends Animal {
    public Fish(int age) {
        super(age);
        System.out.println("我是一直5斤重的魚！");
        System.out.println("我今年" + age + "歲了！");
    }
}

public class Test {
    public static void main(String[] args) {
        Bird bird = new Bird(4);
        bird.service();
        Fish fish = new Fish(2);
    }
}

public interface Fly {
    void service();
}

執(zhí)行問(wèn)題如下：