删除w9

w9/Animal.java

@@ -1,66 +0,0 @@
-// 1. 定义Swimmable接口：包含swim()方法
-public interface Swimmable {
-    // 接口方法默认public abstract，可省略修饰符
-    void swim();
-}
-
-// 2. 定义抽象类Animal：包含抽象方法makeSound()
-public abstract class Animal {
-    // 抽象方法：没有方法体，由子类实现
-    public abstract void makeSound();
-}
-
-// 3. Dog类：继承Animal，实现Swimmable接口
-public class Dog extends Animal implements Swimmable {
-    // 实现父类抽象方法makeSound()
-    @Override
-    public void makeSound() {
-        System.out.println("狗叫：汪汪汪！");
-    }
-
-    // 实现Swimmable接口的swim()方法
-    @Override
-    public void swim() {
-        System.out.println("狗在游泳：狗刨式！");
-    }
-}
-
-// 4. Cat类：仅继承Animal，不实现Swimmable接口
-public class Cat extends Animal {
-    // 实现父类抽象方法makeSound()
-    @Override
-    public void makeSound() {
-        System.out.println("猫叫：喵喵喵！");
-    }
-}
-
-// 5. 主类：测试多态调用
-public class AnimalTest {
-    public static void main(String[] args) {
-        // 多态1：父类引用指向子类对象（Animal多态）
-        Animal dog1 = new Dog();
-        Animal cat1 = new Cat();
-
-        System.out.println("=== Animal多态调用makeSound() ===");
-        dog1.makeSound(); // 调用Dog类的makeSound()
-        cat1.makeSound(); // 调用Cat类的makeSound()
-
-        // 多态2：接口引用指向实现类对象（Swimmable多态）
-        Swimmable dog2 = new Dog();
-        System.out.println("\n=== Swimmable多态调用swim() ===");
-        dog2.swim(); // 调用Dog类的swim()
-
-        // 类型转换：将Animal类型的dog1转为Swimmable，调用swim()
-        System.out.println("\n=== 类型转换后调用swim() ===");
-        if (dog1 instanceof Swimmable) { // 安全判断：避免类型转换异常
-            Swimmable swimmableDog = (Swimmable) dog1;
-            swimmableDog.swim();
-        }
-
-        // Cat无法转换为Swimmable，会抛出异常，因此不执行
-        // if (cat1 instanceof Swimmable) {
-        //     Swimmable swimmableCat = (Swimmable) cat1;
-        //     swimmableCat.swim();
-        // }
-    }
-}

w9/Exception.java

@@ -1,18 +0,0 @@
-import java.io.BufferedReader;
-import java.io.FileReader;
-
-public class ScoreAverage {
-    public static void main(String[] args) {
-        BufferedReader br = new BufferedReader(new FileReader("scores.txt"));
-        String line;
-        int sum = 0;
-        int count = 0;
-        while ((line = br.readLine()) != null) {
-            sum += Integer.parseInt(line);
-            count++;
-        }
-        br.close();
-        double avg = (double) sum / count;
-        System.out.println("平均分：" + avg);
-    }
-}

w9/README.md

@@ -1,2 +0,0 @@
-# java
-