我希望能够在 API 中引发验证和其他异常,并在包装视图中捕获它们,该视图将以 JSON 形式返回错误消息。
我想我可以使用这样的东西:
例外
class APIException(Exception):
def __init__(self, message, status_code=406):
super().__init__(message)
self.status_code = status_code
捕获异常
# Todo: find a better way of handling this. Flask should have some way of handling exceptions better than this
def catch_errors(view):
@functools.wraps(view)
def wrapped_view(**kwargs):
try:
return view(**kwargs)
except APIException as e:
# It seems to hit here
return json_response({'message': str(e)}, e.status_code)
except Exception as e:
# But bubbles up to here and returns this
return json_response({'message': str(e)}, 500)
return wrapped_view
Route
@router.route('/a-route', methods=['POST'])
@catch_errors
def get():
return json_response(ARouteAPI().post(request.get_json()))
API处理后
class ARouteAPI():
def post(data):
if not data.something:
raise APIException("Invalid data error")
我遇到的问题是,无论我抛出什么异常,它都会冒泡到一个完整的异常Exception
并击中500
所以它永远不会返回APIException
.
有谁知道为什么?如何修复它?
或者有更好的方法来处理这个问题吗?
Update
至今仍为此做噩梦。
处理它的更好方法是使用@app.errorhandler
装饰器(在我的例子中@router
是我的蓝图名称,所以我正在使用@router.errorhandler
相反),正如@Hyunwoo 所建议的。
然而,无论抛出什么异常,它总是会遇到 500 错误,我不知道为什么。
我发现了类似的例子,其中调试模式导致问题重新出现,我认为这可能会导致问题,但我将调试模式设置为false
错误处理程序
router = Blueprint('router', __name__)
@router.errorhandler(APIException)
def api_exception_handler(e):
return jsonify({'message': str(e)}, e.status_code), 400
@router.errorhandler(500)
def error_handler(e):
return jsonify({'message': str(e)}), 500 # Always hits this whatever exception is raised
堆栈跟踪
[2018-10-16 23:48:39,767] ERROR in app: Exception on /drone/7 [PUT]
Traceback (most recent call last):
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask/app.py", line 2292, in wsgi_app
response = self.full_dispatch_request()
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask/app.py", line 1815, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask_cors/extension.py", line 161, in wrapped_function
return cors_after_request(app.make_response(f(*args, **kwargs)))
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask/app.py", line 1718, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask/_compat.py", line 35, in reraise
raise value
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask/app.py", line 1813, in full_dispatch_request
rv = self.dispatch_request()
File "/home/sarcoma/PycharmProjects/drone_squadron/venv/lib/python3.5/site-packages/flask/app.py", line 1799, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/sarcoma/PycharmProjects/drone_squadron/drone_squadron/router.py", line 62, in wrapped_view
return view(**kwargs)
File "/home/sarcoma/PycharmProjects/drone_squadron/drone_squadron/router.py", line 159, in drone_detail
return JsonRequestHandler.detail(DroneApi(), item_id)
File "/home/sarcoma/PycharmProjects/drone_squadron/drone_squadron/request/json_request_handler.py", line 39, in detail
return json_response(api.put(item_id, request.get_json()))
File "/home/sarcoma/PycharmProjects/drone_squadron/drone_squadron/api/drone_api.py", line 42, in put
raise APIException("Not enough scrap")
drone_squadron.exception.exceptions.APIException: Not enough scrap
127.0.0.1 - - [16/Oct/2018 23:48:39] "PUT /drone/7 HTTP/1.1" 500 -
错误处理规范
这是输出print(app.error_handler_spec)
正如@Hyunwoo 所建议的。
{None: {
500: {<class 'werkzeug.exceptions.InternalServerError'>: <function error_handler at 0x7fdd0cb6ad08>},
None: {
<class 'sqlalchemy.exc.IntegrityError'>: <function integrity_error_handler at 0x7fdd0cb6ab70>,
<class 'exception.exceptions.APIException'>: <function api_exception_handler at 0x7fdd0cb6abf8>,
<class 'exception.exceptions.ValidationException'>: <function validation_exception_handler at 0x7fdd0cb6ac80>
}}}