OData metadata url request fails if I set the version

Question

The following code gets a 500:

WebRequest request =
  WebRequest.Create("https://services.odata.org/TripPinRESTierService/$metadata");
HttpWebRequest webRequest = request as HttpWebRequest;
webRequest.Accept = "application/atom+xml,application/xml";
request.Headers.Add("DataServiceVersion", "4.0");
request.Headers.Add("OData-MaxVersion", "4.0");
webRequest.AutomaticDecompression =
  DecompressionMethods.Deflate | DecompressionMethods.GZip;

// this throws the 500
var response = request.GetResponse();

But this succeeds:

WebRequest request =
   WebRequest.Create("https://services.odata.org/TripPinRESTierService/$metadata");
HttpWebRequest webRequest = request as HttpWebRequest;
webRequest.Accept = "application/atom+xml,application/xml";
request.Headers.Add("OData-MaxVersion", "4.0");
webRequest.AutomaticDecompression =
  DecompressionMethods.Deflate | DecompressionMethods.GZip;
var response = request.GetResponse();

This throws error:

WebRequest request = 
  WebRequest.Create("https://services.odata.org/TripPinRESTierService/Airlines");
HttpWebRequest webRequest = request as HttpWebRequest;
webRequest.Accept = "application/atom+xml,application/xml";
request.Headers.Add("DataServiceVersion", "4.0");
request.Headers.Add("OData-MaxVersion", "4.0");
webRequest.AutomaticDecompression =
  DecompressionMethods.Deflate | DecompressionMethods.GZip;

// this throws the 500
var response = request.GetResponse();

Is there something special where I should not specify the DataServiceVersion when requesting the metadata?

Shimmy Weitzhandler · Accepted Answer · 2020-04-13T04:25:37.717

0

According to the docs, the header for the OData-version, is OData-Version, not DataServiceVersion.

Based on my test using Postman, this is what was throwing the 500 error.

And BTW, consider using HttpClient instead of WebClient, works asynchronously, and is lighter than WebClient. See this and this.

edited Apr 13 '20 at 04:25

answered Apr 13 '20 at 04:20

Shimmy Weitzhandler

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First, thank you. Did it used to be DataServiceVersion? I don't see how we would have had something wrong in there otherwise. – David Thielen Apr 13 '20 at 10:50
Yes David, that threw the 500 error. As soon as I removed or fixed this header it all worked well. – Shimmy Weitzhandler Apr 13 '20 at 11:56
Yes, but is this new to version 4? Because in versions 2 & 3 I think it uses DataServiceVersion (and MaxDataServiceVersion)? thanks – David Thielen Apr 13 '20 at 19:18
That I don't know. It might have ignored those headers too without you knowing about it. – Shimmy Weitzhandler Apr 15 '20 at 07:33

OData metadata url request fails if I set the version

1 Answers1