Using HttpWebRequest/Response, and the Trailer headers in the chunked-encoded response are being thrown away (I've actually stepped through the .Net 4.0 reference source to see where it calls RemoveTrailers after the final chunk). Is there any way to retrieve those headers? Also, does anyone know why this behavior is in place to begin with?
In case anyone asks, no, I can't ensure that the trailer headers are moved to the rest of the headers. This is simply the data stream format I have to work with.
I dont think there is any way to do that. As to why it is like this, when this feature was first being implemented, there was no known HTTP server that sent headers in chunked response trailers.
What kind of server is this? Is this a custom server that is doing this?
If you absolutely care about this, you can find a feature request at the MS connect website (http://connect.microsoft.com).
Related
I'm building a microservice which one of it's API's expects a file and some parameters which the API will process and return a response for.
I've searched and found some references, mostly pointing towards form-data (multipart), however they mostly refer to client to service and not service to service like in my case.
I'll be happy to know what is the best practice for this case for both the client (a service actually) and me.
I would also suggest to perform a POST request (multipart) to a service endpoint that can process/accept a byte stream wrapped into the provided HTML body(s). A PUT request may also work in some cases.
Your main concerns will consist in binding enough metadata to the request so that the remote service can correctly handle it. This include in particular the following headers:
Content-Type: to provide the MIME type of the data being transferred and enable its proper processing.
Content-Disposition: to provide additional information about the body part such as the file name.
I personally believe that a single request is enough (in contrast to #Evert suggestion) as it will result in less overhead overall and will keep things simple (and RESTful) by avoiding any linking (or state) between successive requests.
I would not wrap data in form-data, because it just adds to the total body size. You can just put the entire raw file in the body of a PUT or POST request.
If you also need to send meta-data, I would suggest 2 requests. If you absolutely can't do 2 requests, form-data might still be the best option and it does work server-to-server.
I try to get some info from other sites with xbuf_frurl.
I got some site OK but some Not OK.
By Now, I still can not make sure what is going wrong.
But some sites are missing the content length header.
Who can tell whether xbuf_frurl() relies on the (potentially missing) content length header, esp. when growing the buffer?
xbuf_frurl() is indeed reading a body IF an HTTP content-length header is present. It will not try to decode chunked responses.
To deal with those servers using chunked replies, use the G-WAN curl.c example provided with the distribution. With libcurl you have even the opportunity to use SSL/TLS.
If that's not resolving your problem, the only way to troubleshoot this kind of issues is to give a non-working example, with both the full request that you have sent and the full reply received from the server.
That's why the xbuf_xcat("%v") format has been added: to give hexdumps, even with binary replies.
Edit your question and add this information to let people help you with a well-defined problem.
I'm designing an API to be as HTTP compliant as I can. This includes sending specific response codes back and using the Accept header to specify versions and response types.
I understand this may appear subjective, but I'm sure there's a conventional way of doing this. I have a set of response types that the API supports, along with a vendor-specific mime type to specify the type and version.
Currently, when the client specifies a non-existant version or type, I'm just returning a 400 Bad Request with an empty body, however, I want to return a useful error message. In the event that I don't know the response type, I feel a bit dirty responding with plain text (or defaulting to JSON). Is there a header I'm missing, or some convention that I should follow? I want to get this one right from the offset.
Thanks, and my best,
Jamie
Try the status code of 406 Not Acceptable.
http://support.microsoft.com/kb/943891/
This is a list of HTTP sub-codes supported by Microsoft IIS. I've found this page damn handy since it gives you some insight into the messages they use to handle various errors. There are some HTTP sub-codes that refer to headers.
Just wondering if there is anyway to save data across the line without the response coming back. i.e. Im using the objc odata sdk. If I create an employee entity on the ipad, than I save it, I dont need to receive the the saved entity back. So really its sending the data across the line than returning it for no reason. Only really need to send it across.
Any ideas on how I can set saves to be push to server and not have to wait for the return?
Thanks in advance
In the latest CTP (http://blogs.msdn.com/b/astoriateam/archive/2011/10/13/announcing-wcf-data-services-oct-2011-ctp-for-net-4-and-silverlight-4.aspx) you can use the Prefer header. The client can send the request with Prefer header set to return-no-content and the server will send an empty response back. The header is described here: https://datatracker.ietf.org/doc/html/draft-snell-http-prefer-01.
How do I read the Response Headers that are being sent down in a page ? I want to be able to read the header values and modify some of them. This is for an ASP.NET 1.1 application but I would be curious to know if it can done in any version of ASP.NET.
The reason for doing this is someone may have added custom headers of their own before the point I am examining the response - so I cannot blindly clear all the headers and append my own - I need to read the all the headers so I can modify the appropriate ones only.
HttpContext.Current.Response (Its a HTTPResponse), exposed ClearHeaders(), AddHeaders() and AppendHeaders().
Not as direct as it is now in later version of ASP.NET, but should be enough to let you modify the headers you wanted to modify.
http://msdn.microsoft.com/en-us/library/system.web.httpresponse_members(VS.71).aspx
AFAIK it cannot be done in ASP.NET 1.1. There is no way for you to get at the response headers - request headers are available but not response headers.
I am not sure if you can do this in other stacks like Java, LAMP though and I am curious to find out...