这是App Engine的一个已知错误.

This is a known error with App Engine.

引发异常时，端点没有设置正确的Content-Length标头:

Endpoints does not set the correct Content-Length header when you raise an exception:

https://code.google.com/p/googleappengine/issues/detail?id = 10544

要修复此问题，上面的链接中包含一个diff文件，或者按照我的指示由您自己临时对其进行修补.

To fix it there is a diff file included in the link above, or follow my instructions to temporarily patch it by yourself.

1.打开apiserving.py

1. Open apiserving.py

在Mac上，您可以在以下位置找到文件:

On a mac you can find the file at:

/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/lib/endpoints-1.0/endpoints

2.找到以下部分(第467行):

它应该看起来像这样:

headers_dict = dict([(k.lower(), v) for k, v in headers])
if self.__is_json_error(status, headers_dict):
  status, body = self.protorpc_to_endpoints_error(status, body)

3.更改为此:

headers_dict = dict([(k.lower(), v) for k, v in headers])
if self.__is_json_error(status, headers_dict):
  pre_body_length = len(body)
  status, body = self.protorpc_to_endpoints_error(status, body)
  post_body_length = len(body)
  if pre_body_length != post_body_length:
    for index, header in enumerate(headers):
      header_key, _header_value = header
      if header_key == 'content-length':
        headers[index] = (header_key, str(post_body_length))
        break

4.全部完成！

端点将返回正确的Content-Length，WebOb将很高兴，并且您的API测试将正常进行:)

Endpoints will return the correct Content-Length, WebOb will be happy and your API tests will be working :)