接口4

public interface CanSwim {

    void Swim();
}

public interface CanFly {

    void Fly();
}

public class Hero extends ActionCharacter implements CanSwim, CanFly {

    String name;

    Hero(String name) {
        this.name = name;
    }

    @Override
    public void Fly() {
        System.out.println(this.name + "会飞。");

    }

    @Override
    public void Swim() {
        System.out.println(this.name + "会游泳。");

    }

}

public class Adventure {

    public static void main(String[] args) {
        Hero hb = new Hero("张三");
        hb.Swim();
        hb.fight("");
        hb.Fly();

        CanFly cf = new Hero("李四");
        cf = hb;
        cf.Fly();

        CanSwim cs = new Hero("王五");
        cs = hb;
        cs.Swim();

        ActionCharacter ac = new Hero("马六");
        ac = hb;
        ac.speak("大家跟我一起战斗！");
        ac.fight("发射！");
    }

}

结果：