上传文件至 'w6'

w6/Animal.java

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+abstract class Animal {
+    public abstract void makeSound();
+}
+
+interface Swimmable {
+    void swim();
+}
+
+class Dog extends Animal implements Swimmable {
+    @Override
+    public void makeSound() {
+        System.out.println("🐶 汪汪汪！（Dog叫声）");
+    }
+
+    @Override
+    public void swim() {
+        System.out.println("🐶 狗狗在水中快乐地游泳～");
+    }
+}
+
+
+class Cat extends Animal {
+    @Override
+    public void makeSound() {
+        System.out.println("🐱 喵喵喵！（Cat叫声）");
+    }
+
+}
+

w6/TestAnimal.java

@@ -0,0 +1,35 @@
+public class TestAnimal {
+
+    public static void animalSound(Animal a) {
+        a.makeSound();
+    }
+
+
+    public static void trySwim(Animal a) {
+        if (a instanceof Swimmable) {
+            Swimmable s = (Swimmable) a;
+            s.swim();
+        } else {
+            System.out.println("❌ 这只动物不会游泳！");
+        }
+    }
+
+    public static void main(String[] args) {
+
+        Animal dog = new Dog();
+        Animal cat = new Cat();
+
+        System.out.println("=== 1. 多态调用叫声（抽象类多态） ===");
+        animalSound(dog);
+        animalSound(cat);
+
+        System.out.println("\n=== 2. 多态调用游泳（接口多态） ===");
+        trySwim(dog);
+        trySwim(cat);
+
+
+        System.out.println("\n=== 3. 接口引用直接调用 ===");
+        Swimmable swimmer = new Dog();
+        swimmer.swim();
+    }
+}