为什么设置POST内容类型:"Application/Json"导致“错误请求".在REST WebService上? [英] Why Setting POST Content-type:"Application/Json" causes a "Bad Request" on REST WebService?
问题描述
使用我的Web服务时遇到一个奇怪的问题:
I've a strange problem using my web service :
当我作为客户端在不设置任何类型内容"标头的情况下将表单发布到REST Web服务时，一切正常.我在服务器上接到电话，并且Json文本可用.
When I, as a client, POST a form to the REST Web Service without setting any "type-content" header, things works fine. I get the call on the server and the Json text is available.
如果我作为客户端将我的发布请求的内容类型标头设置为"application/json"，则服务器会通过错误请求(400)"进行回复.
If I, as a client, sets the content-type header of my post request to "application/json", the server reply by a "Bad Request (400)".
Web服务方法是:
<WebInvoke(UriTemplate:="Login", Method:="POST")>
Public Function LoginFormAccess(data As IO.Stream) As String
(...)
end function
如果我不提及"Application/Json"，则可以检索发布在 data 流中的客户端json类型的正文.如果这样做，我会得到错误请求的答案.
If I don't mention "Application/Json", I can retrieve the client json-typed body, posted in the data stream. If I do, I get the Bad Request answer.
为什么关于内容类型值的行为有如此大的差异，又有什么提供这种差异?该方法是否需要其他类型的参数，还是必须更改或检查其他内容?
Why is there a such great difference of behavior concerning the content-type value and what is provide such a difference ? Does the method needs another type of parameter, or something else has to be changed or checked?
已添加:如果内容类型为"Application/Json"，并且主体为空，则可以正常工作...！
-
注释1:实例化负责应答呼叫的班级. (一种 跟踪new()证明了这一点).因此，问题似乎在于服务器未找到合适的方法来调用该对象...
Note 1 : The class responsible to answer the call is instantiated. (A trace in the new() proves it). So, the problem seems to be that the server does not find a proper method to call on that object...
注2:我在使用不同的客户端时遇到了这个问题，所以我很漂亮 当然是服务器端问题.
Note 2 : I've this problem using different clients, so I'm pretty sure is a server-side problem.
注3:我使用了WCF REST服务应用程序模板来创建 我的项目.
Note 3 : I've used a WCF REST Service Application Template to create my project.
注释4:提及"ResponseFormat = WebMessageFormat.Json"和"RequestFormat = WebMessageFormat.Json"无济于事.
Note 4 : Mentioning "ResponseFormat=WebMessageFormat.Json" and "RequestFormat=WebMessageFormat.Json" does not help.
推荐答案
将content-type标头添加到请求时，您将在您的数据中指定数据的内容类型请求，而不是您希望看到的内容返回.
When you add a content-type header to your request, you are specifying the content type of the data in your request, not the content you expect to see returned.
根据您发布的内容，我敢打赌，您正在将XML发布到服务，并且当将content-type设置为JSON时，将破坏服务器解析正文的能力.您可能会模棱两可的声明如果内容类型为"Application/Json"而主体为空，则可能会证实这一点(假设您的意思是请求的主体，而不是响应的主体).
My bet from what you've posted is that you are posting XML to the service, and when you set content-type to JSON you are breaking the server's ability to parse the body. Your ambiguous statement that it works "If the content-type is "Application/Json" AND the body is empty" might bear this out (assuming you mean the body of your request, not of the response).
您可以通过添加XML而不是JSON的内容类型来证明这一点-如果它与您的请求的实际内容匹配，则可以正常工作.
You could prove this by adding a content type of XML instead of JSON - which, if it matches the actual body of your request, will work just fine.
简而言之:由于您的请求指定的是JSON内容，而您没有发送JSON，因此出现了错误请求"错误.
In short: it's giving a "Bad Request" error because your request is specifying JSON content and you are not sending JSON.
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