java/w7/ScoreAverageCalculator.java

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

public class ScoreAverageCalculator {
    public static void main(String[] args) {
        String fileName = "scores.txt";
        int sum = 0;
        int count = 0;
        
        // try-with-resources 自动关闭流
        try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
            String line;
            
            while ((line = br.readLine()) != null) {
                // 跳过空行
                if (line.trim().isEmpty()) {
                    continue;
                }
                
                try {
                    int score = Integer.parseInt(line.trim());
                    sum += score;
                    count++;
                } catch (NumberFormatException e) {
                    // 数字格式错误处理
                    System.err.println("数字格式错误，忽略该行内容: " + line);
                }
            }
            
            // 计算并输出平均分
            if (count > 0) {
                double average = (double) sum / count;
                System.out.println("成功读取 " + count + " 个成绩");
                System.out.println("总分: " + sum);
                System.out.println("平均分: " + average);
            } else {
                System.err.println("文件中没有有效的成绩数据");
            }
            
        } catch (IOException e) {
            // 文件不存在或读取错误处理
            System.err.println("文件操作错误: " + e.getMessage());
            if (e instanceof java.io.FileNotFoundException) {
                System.err.println("请检查文件 \"" + fileName + "\" 是否存在");
            }
        }
    }
}