上传文件至 'w6'

w6/Animal.java

@@ -0,0 +1,11 @@
+package org.example;
+
+public abstract class Animal {
+    String name;
+
+    public Animal(String name) {
+        this.name = name;
+    }
+
+    public abstract void makeSound();
+}

w6/AnimalTest.java

@@ -0,0 +1,22 @@
+package org.example;
+
+public class AnimalTest {
+    public static void main(String[] args) {
+
+        Animal dog = new Dog("Buddy");
+        Animal cat = new Cat("Kitty");
+
+        dog.makeSound();
+        cat.makeSound();
+
+        if (dog instanceof Swimmable) {
+            ((Swimmable) dog).swim();
+        }
+
+        if (cat instanceof Swimmable) {
+            ((Swimmable) cat).swim();
+        } else {
+            System.out.println(cat.name + " cannot swim.");
+        }
+    }
+}

w6/Cat.java

@@ -0,0 +1,13 @@
+package org.example;
+
+public class Cat extends Animal {
+
+    public Cat(String name) {
+        super(name);
+    }
+
+    @Override
+    public void makeSound() {
+        System.out.println(name + " says: Meow!");
+    }
+}

w6/Dog.java

@@ -0,0 +1,18 @@
+package org.example;
+
+public class Dog extends Animal implements Swimmable {
+
+    public Dog(String name) {
+        super(name);
+    }
+
+    @Override
+    public void makeSound() {
+        System.out.println(name + " says: Woof!");
+    }
+
+    @Override
+    public void swim() {
+        System.out.println(name + " is swimming!");
+    }
+}

w6/ScoreReader.js

@@ -0,0 +1,45 @@
+package org.example;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class ScoreReader {
+    public static void main(String[] args) {
+
+    int sum = 0;
+    int count = 0;
+
+    // try-with-resources：自动关闭流，不需要手动 br.close()
+    try (BufferedReader br = new BufferedReader(new FileReader("scores.txt"))) {
+
+    String line;
+    while ((line = br.readLine()) != null) {
+    try {
+    sum += Integer.parseInt(line.trim());
+    count++;
+} catch (NumberFormatException e) {
+    // 处理数字格式错误
+    System.out.println("跳过无效数据：" + line);
+}
+}
+
+if (count > 0) {
+    double average = (double) sum / count;
+    System.out.println("总分：" + sum);
+    System.out.println("人数：" + count);
+    System.out.printf("平均分：%.2f%n", average);
+} else {
+    System.out.println("文件中没有有效成绩。");
+}
+
+} catch (FileNotFoundException e) {
+    // 处理文件不存在
+    System.out.println("错误：找不到文件 scores.txt，请检查路径。");
+} catch (IOException e) {
+    // 处理读取错误
+    System.out.println("错误：读取文件时发生异常：" + e.getMessage());
+}
+}
+}