w7

w7/ScoreAverageCalculator.java

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+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class ScoreAverageCalculator {
+    public static void main(String[] args) {
+        int sum = 0;
+        int count = 0;
+
+        // try-with-resources 自动关闭流
+        try (BufferedReader br = new BufferedReader(new FileReader("scores.txt"))) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                line = line.trim();
+                if (line.isEmpty()) {
+                    continue;
+                }
+                int score = Integer.parseInt(line);
+                sum += score;
+                count++;
+            }
+
+            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("文件无有效成绩！");
+            }
+        } catch (java.io.FileNotFoundException e) {
+            System.out.println("错误：文件未找到或无法访问！" + e.getMessage());
+        } catch (NumberFormatException e) {
+            System.out.println("错误：包含非数字数据！" + e.getMessage());
+        } catch (IOException e) {
+            System.out.println("错误：读取文件失败！" + e.getMessage());
+        }
+    }
+}

w7/scores.txt

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+85
+92
+78
+66