java/w7/ScoreAvg.java

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ScoreAvg {
    public static void main(String[] args) {
        String fileName = "scores.txt";
        BufferedReader br = null;
        int sum = 0;
        int count = 0;

        // ========================
        // 题目要求：try catch finally
        // ========================
        try {
            // 1. 打开文件
            br = new BufferedReader(new FileReader(fileName));

            // 2. 读取每一行
            String line;
            while ((line = br.readLine()) != null) {
                line = line.trim();
                if (line.isEmpty()) continue;

                try {
                    int score = Integer.parseInt(line);
                    sum += score;
                    count++;
                } catch (NumberFormatException e) {
                    System.out.println("格式错误：" + line);
                }
            }

            // 3. 输出结果
            System.out.println("总分：" + sum);
            System.out.println("平均分：" + (double) sum / count);

        } catch (IOException e) {
            // 异常处理
            System.out.println("文件操作失败！");
            e.printStackTrace();

        } finally {
            // ========================
            // finally：必须执行，关闭流！
            // 题目要求必须写这里！
            // ========================
            try {
                if (br != null) {
                    br.close();
                    System.out.println("流已关闭！");
                }
            } catch (IOException e) {
                System.out.println("关闭失败！");
            }
        }
    }
}