java/w6/Animal.java

package w6;

public abstract class Animal{
    public abstract void makeSound();
    public interface Swimmable{
        void swim();
        public class Dog extends Animal implements Swimmable{
            @Override
            public void makeSound(){
                System.out.println("汪汪汪！");
            }
                @Override
                public void swim(){
                    System.out.println("狗会游泳");
                }
            }
            public class Cat extends Animal {
                @Override
                public void makeSound() {
                    System.out.println("喵喵喵！");
                }
            }
            public class AnimalTest {
                public static void main(String[] args) {
                    Animal dog = new Dog();
                    Animal cat = new Cat();
                    System.out.println("===动物叫声测试===");
                    dog.makeSound();
                    cat.makeSound();
                    System.out.println("===游泳能力测试===");
                    if (dog instanceof Swimmable) {
                        ((Swimmable) dog).swim();
                    }
                    if (cat instanceof Swimmable) {
                        ((Swimmable) cat).swim();
                    } else {
                        System.out.println("猫不会游泳");
                    }
                }
            } 
    }
}