1【需求】：上传图片到当前项目中使用字节缓冲输入输出流2【需求】：上传一个记事本文件到当前项目中使用字符文件输入输出流。3【需求】：添加5个学生的姓名到nametxt文件中使用集合的方式用字符缓冲输入输出流4【需求】----点名器：在第3个实验中生成一个nametxt文件里面存储了班级同学的姓名每个姓名占一行要求通过程序实现随机点名器。【思路】1 创建字符缓冲输入流对象2 创建ArrayList集

1. 实现代码：

File file = new File("test.jpg"); try (FileInputStream fis = new FileInputStream(file); FileOutputStream fos = new FileOutputStream("test_copy.jpg"); BufferedInputStream bis = new BufferedInputStream(fis); BufferedOutputStream bos = new BufferedOutputStream(fos)) { byte[] buffer = new byte[1024]; int len; while ((len = bis.read(buffer)) != -1) { bos.write(buffer, 0, len); } } catch (IOException e) { e.printStackTrace(); }

2. 实现代码：

File file = new File("test.txt"); try (FileReader fr = new FileReader(file); FileWriter fw = new FileWriter("test_copy.txt"); BufferedReader br = new BufferedReader(fr); BufferedWriter bw = new BufferedWriter(fw)) { String line; while ((line = br.readLine()) != null) { bw.write(line); bw.newLine(); } } catch (IOException e) { e.printStackTrace(); }

3. 实现代码：

List names = new ArrayList<>(); names.add("Alice"); names.add("Bob"); names.add("Charlie"); names.add("David"); names.add("Eva"); File file = new File("name.txt"); try (FileWriter fw = new FileWriter(file); BufferedWriter bw = new BufferedWriter(fw)) { for (String name : names) { bw.write(name); bw.newLine(); } } catch (IOException e) { e.printStackTrace(); }

4. 实现代码：

List names = new ArrayList<>(); File file = new File("name.txt"); try (FileReader fr = new FileReader(file); BufferedReader br = new BufferedReader(fr)) { String line; while ((line = br.readLine()) != null) { names.add(line); } } catch (IOException e) { e.printStackTrace(); } Random random = new Random(); int index = random.nextInt(names.size()); System.out.println("Selected student: " + names.get(index));

5. 实现代码：

class User implements Serializable { private static final long serialVersionUID = 1L; private String name; private int age;

public User(String name, int age) {
    this.name = name;
    this.age = age;
}

@Override
public String toString() {
    return "User{" +
            "name='" + name + '\'' +
            ", age=" + age +
            '}';
}

}

File file = new File("users.dat"); try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(file)); ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file))) { User user = new User("Alice", 20); oos.writeObject(user); User userCopy = (User) ois.readObject(); System.out.println(userCopy); } catch (IOException | ClassNotFoundException e) { e.printStackTrace(); }

6. 实现代码：

List users = new ArrayList<>(); users.add(new User("Alice", 20)); users.add(new User("Bob", 21)); users.add(new User("Charlie", 22)); File file = new File("users.dat"); try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(file)); ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file))) { for (User user : users) { oos.writeObject(user); } Object obj; while ((obj = ois.readObject()) != null) { User userCopy = (User) obj; System.out.println(userCopy); } } catch (IOException | ClassNotFoundException e) { e.printStackTrace();