java/w7/ScoreAverage.java

package java01;  
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class ScoreAverage {
    public static void main(String[] args) {
        int sum = 0;
        int count = 0;
        try (BufferedReader br = new BufferedReader(new FileReader("scores.txt"))) {
            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("无效数据，跳过：" + line);
                }
            }

            if (count > 0) {
                double average = (double) sum / count;
                System.out.println("总分：" + sum);
                System.out.println("有效人数：" + count);
                System.out.printf("平均分：%.2f\n", average);
            } else {
                System.out.println("无有效成绩");
            }

        } catch (java.io.FileNotFoundException e) {
            System.out.println("错误：未找到 scores.txt 文件");
        } catch (IOException e) {
            System.out.println("读取文件时发生IO异常");
        }
    }
}