diff --git a/w7/20.jpg b/w7/20.jpg
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diff --git a/w7/35.jpg b/w7/35.jpg
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diff --git a/w7/ScoreCalculator.java b/w7/ScoreCalculator.java
new file mode 100644
index 0000000..5155f79
--- /dev/null
+++ b/w7/ScoreCalculator.java
@@ -0,0 +1,71 @@
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class ScoreCalculator {
+
+    public static void main(String[] args) {
+        String fileName = "java/w7/ scores";
+        double average = calculateAverageScore(fileName);
+
+        if (!Double.isNaN(average)) {
+            System.out.printf("平均分: %.2f%n", average);
+        }
+    }
+
+    /**
+     * 计算成绩文件的平均分
+     * @param fileName 文件名
+     * @return 平均分，如果出错返回 NaN
+     */
+    public static double calculateAverageScore(String fileName) {
+        int sum = 0;
+        int count = 0;
+
+        // 1. 检查文件是否存在
+        Path filePath = Paths.get(fileName);
+        if (!Files.exists(filePath)) {
+            System.err.println("错误: 文件 '" + fileName + "' 不存在！");
+            return Double.NaN;
+        }
+
+        // 2. 使用 try-with-resources 确保流自动关闭
+        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，记录错误但继续处理其他行
+                    System.err.println("警告: 无效的数据格式 '" + line + "'，已跳过此条记录");
+                }
+            }
+
+            // 检查是否有有效数据
+            if (count == 0) {
+                System.err.println("错误: 文件中没有有效的成绩数据！");
+                return Double.NaN;
+            }
+
+            return (double) sum / count;
+
+        } catch (IOException e) {
+            // 读取错误
+            System.err.println("错误: 读取文件 '" + fileName + "' 时发生异常！");
+            System.err.println("详细信息: " + e.getMessage());
+            return Double.NaN;
+        }
+        // 无需显式 close()，try-with-resources 会自动处理
+    }
+}
\ No newline at end of file
diff --git a/w7/scores b/w7/scores
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index 0000000..35d93ee
--- /dev/null
+++ b/w7/scores
@@ -0,0 +1,5 @@
+85
+90
+78
+92
+88
\ No newline at end of file