完善后端日志

backend/app/services/file_service.py

@@ -3,6 +3,7 @@
 """
 import os
 import shutil
+import logging
 from pathlib import Path
 from datetime import datetime
 from typing import Optional
@@ -10,6 +11,8 @@ import uuid
 
 from app.config import settings
 
+logger = logging.getLogger(__name__)
+
 
 class FileService:
     """文件服务类，负责文件的存储、读取和管理"""
@@ -17,6 +20,7 @@ class FileService:
     def __init__(self):
         self.upload_dir = Path(settings.UPLOAD_DIR)
         self._ensure_upload_dir()
+        logger.info(f"FileService 初始化，上传目录: {self.upload_dir}")
 
     def _ensure_upload_dir(self):
         """确保上传目录存在"""
@@ -56,6 +60,8 @@ class FileService:
         with open(file_path, 'wb') as f:
             f.write(file_content)
 
+        file_size = len(file_content)
+        logger.info(f"文件已保存: {filename} -> {file_path} ({file_size} bytes)")
         return str(file_path)
 
     def read_file(self, file_path: str) -> bytes: