java/W7/ScoreAverage.java

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

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

        // try-with-resources 自动关闭文件流
        try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
            String line;
            while ((line = br.readLine()) != null) {
                line = line.trim();
                if (line.isEmpty()) {
                    continue; // 跳过空行
                }

                // 处理数字格式错误
                try {
                    int score = Integer.parseInt(line);
                    sum += score;
                    count++;
                } catch (NumberFormatException e) {
                    System.err.println("警告：无法解析为整数，跳过该行内容：" + line);
                }
            }

            // 计算并输出平均分
            if (count > 0) {
                double average = (double) sum / count;
                System.out.printf("总分：%d，有效成绩数：%d，平均分：%.2f%n", sum, count, average);
            } else {
                System.out.println("文件中没有有效的成绩数据。");
            }

        } catch (IOException e) {
            // 处理文件不存在、读取错误等IO异常
            System.err.println("文件操作出错：" + e.getMessage());
            e.printStackTrace();
        }
    }
}