记一次文件上传遇到的坑(文件名|文件格式乱码)

前端通过form-data的方式上传文件，后端解析保存，一般都比较简单；

1.前端直接通过form/data给后端传值，后端做数据持久化

    def post(self, *args, **kwargs):
        box = self.get_argument('box', None)
        size = int(self.request.headers.get('Content-Length'))
        if size / 1000.0 > 2000:
            self.set_status(400)
            self.write({'msg': self._("上传图片不能大于2M.")})
            return
        file_info = self.request.files['file'][0]
        file_name = generate_file_name(file_info['filename'])
        if not file_name:
            self.write_rows(code=-1, msg=self._('Invalid file name'))
            return
        year_month, day = time.strftime("%Y%m"), time.strftime("%d")
        path = os.path.join(FILE_UPLOAD_PATH, year_month, day)
        # 大图
        absolute_path = os.path.join(path, file_name)
        app_path = absolute_path[absolute_path.rindex('upload'):]
        # 缩略图
        crop_absolute_path = os.path.join(path, 'crop'+file_name)
        crop_app_path = crop_absolute_path[crop_absolute_path.rindex('upload'):]

        self.create_dir(path)
        try:
            with open(absolute_path, 'wb') as f:
                f.write(file_info['body'])
                if box:
                    from utils import crop_image
                    crop_image(crop_absolute_path, box)
                self.write(json_encode({
                    'path': app_path,
                    'crop_path': crop_app_path
                }))
        except Exception as e:
            app_log.error(e)
            raise HTTPError(500)

2.文件经过一层中转，按照这种方式上传，最终可能获取不到原始的文件名，也不知道文件类型 

    async def post(self, *args, **kwargs):
        """文件上传"""
        uid = self.current_user['_id']
        sign = self.cal_signature(uid=uid, body=None)
        files = self.request.files['files'][0]
        res = worker.file_upload(uid=uid, sign=sign, files={'file': (files.filename, files.body, files.content_type)})
        return await self.render_json(rows=json.loads(res))

。。懒得写了。就这样吧