Django 修改request body 属性 AttributeError: can't set attribute

╰+攻爆jí腚メ 2022-04-02 02:46 521阅读 0赞

先说结论，使用下面代码可以改变request.body的值

request._body = b'xxxxxxxxx'

# Django 修改request body 属性 AttributeError: can't set attribute #

现在有这样一个需求，增加一个拦截器，将每一个Http请求都拦下来，之后改变http body（request.body）的值。

但是当我们直接改变时，会抛出下列异常“AttributeError: can’t set attribute”

request.body = b'{"key": "value2"}'
    
    Traceback (most recent call last):
      File "D:\Python36\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
        response = get_response(request)
      File "D:\Python36\lib\site-packages\django\utils\deprecation.py", line 90, in __call__
        response = self.process_request(request)
      File "C:\Users\Administrator\PycharmProjects\CeleryDemo\CeleryDemo\UserMiddleware.py", line 22, in process_request
        request.body = b'{"key": "value2"}'
    AttributeError: can't set attribute

### 查看Django源代码 ###

class HttpRequest:
    	@property
    	def body(self):
    	    if not hasattr(self, '_body'):
    	        if self._read_started:
    	            raise RawPostDataException("You cannot access body after reading from request's data stream")
    	
    	        # Limit the maximum request data size that will be handled in-memory.
    	        if (settings.DATA_UPLOAD_MAX_MEMORY_SIZE is not None and
    	                int(self.META.get('CONTENT_LENGTH') or 0) > settings.DATA_UPLOAD_MAX_MEMORY_SIZE):
    	            raise RequestDataTooBig('Request body exceeded settings.DATA_UPLOAD_MAX_MEMORY_SIZE.')
    
                try:
                    self._body = self.read()
                except IOError as e:
                    raise UnreadablePostError(*e.args) from e
                self._stream = BytesIO(self._body)
            return self._body

这段代码可以看出来，它的body属性是用@property修饰的，所以是只读属性。从源码中可以看出，body属性是取自\_body，所以只需要改\_body即可达到目的。

request._body = b'{"key": "value2"}'