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

public class ScoreCalculator {
    public static void main(String[] args) {
        // 使用try-with-resources确保流自动关闭
        try (BufferedReader reader = new BufferedReader(new FileReader("scores.txt"))) {
            String line;
            int lineNumber = 0;
            while ((line = reader.readLine()) != null) {
                lineNumber++;
                try {
                    // 处理每行数据
                    String[] parts = line.split(",");
                    if (parts.length < 2) {
                        throw new IllegalArgumentException("第" + lineNumber + "行数据格式错误: 缺少必要字段");
                    }
                    
                    String studentId = parts[0].trim();
                    if (studentId.isEmpty()) {
                        throw new IllegalArgumentException("第" + lineNumber + "行数据格式错误: 学号为空");
                    }
                    
                    try {
                        double score = Double.parseDouble(parts[1].trim());
                        System.out.println("学号: " + studentId + ", 成绩: " + score);
                    } catch (NumberFormatException e) {
                        System.err.println("第" + lineNumber + "行数据格式错误: 成绩不是有效数字 - " + e.getMessage());
                    }
                } catch (IllegalArgumentException e) {
                    System.err.println(e.getMessage());
                }
            }
        } catch (FileNotFoundException e) {
            System.err.println("文件不存在: " + e.getMessage());
        } catch (IOException e) {
            System.err.println("文件读取错误: " + e.getMessage());
        } catch (Exception e) {
            System.err.println("发生未知错误: " + e.getMessage());
        }
    }
}