平均分

w7/ScoreAverage.java

@@ -0,0 +1,37 @@
+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 会自动关闭流，无需手动调用 close()
+        try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                try {
+                    int score = Integer.parseInt(line.trim());
+                    sum += score;
+                    count++;
+                } catch (NumberFormatException e) {
+                    System.err.println("数字格式错误，跳过无效数据行：" + line);
+                }
+            }
+
+            if (count == 0) {
+                System.out.println("文件中没有有效成绩数据，无法计算平均分。");
+            } else {
+                double average = (double) sum / count;
+                System.out.printf("平均分：%.2f%n", average);
+            }
+
+        } catch (IOException e) {
+            System.err.println("文件读取错误：" + e.getMessage());
+        } catch (Exception e) {
+            System.err.println("发生意外错误：" + e.getMessage());
+        }
+    }
+}