Trapping exception? GET request with body RSS

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  LittleClive

  Member

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  65 Posts

  Trapping exception? GET request with body

  Feb 23, 2012 08:37 AM|LINK

  With the default "Values" service template. If I use a GET request with a body and an accept header of application/json, I get the following exception:

  {"ExceptionType":"System.InvalidOperationException","Message":"No 'MediaTypeFormatter' is available to read an object of type 'Int32' with the media type ''undefined''.","StackTrace":"   at System.Net.Http.ObjectContent.SelectAndValidateReadFormatter(Boolean acceptNullFormatter)\u000d\u000a   at System.Net.Http.ObjectContent.ReadAsyncInternal[T](Boolean allowDefaultIfNoFormatter)\u000d\u000a   at System.Web.Http.ModelBinding.RequestContentReader.ReadWholeBodyAsync(HttpActionContext actionContext, Type modelType)\u000d\u000a   at System.Web.Http.ModelBinding.RequestContentReader.ReadContentAsync(HttpActionContext actionContext)\u000d\u000a   at System.Web.Http.ModelBinding.DefaultActionValueBinder.BindValuesAsync(HttpActionContext actionContext, CancellationToken cancellationToken)\u000d\u000a   at System.Web.Http.ApiController.<>c__DisplayClass3.<ExecuteAsync>b__0()\u000d\u000a   at System.Web.Http.ApiController.ExecuteAsync(HttpControllerContext controllerContext, CancellationToken cancellationToken)\u000d\u000a   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsyncInternal(HttpRequestMessage request, CancellationToken cancellationToken)\u000d\u000a   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)"}

   

  The request I sent is:

  GET http://localhost:39332/api/values/1 HTTP/1.1
  Accept: application/json
  Accept-Language: en-GB
  User-Agent: Fiddler
  Accept-Encoding: gzip, deflate
  Connection: Keep-Alive
  Host: localhost:39332
  Content-Length: 3
  
  sss
  

  Note the "sss" content. Clearly this request is incorrect because a GET shouldn't have a body but my question is: how do I trap this exception to log it? I've tried the following:

  • Custom ExceptionFilter on the service - but it doesn't seem to have got this far
  • Custom ActionFilterAttribute in configuration.Filters and overriding OnActionExecuted but this is never called either
  • DelegatingHandler - this can trap the 500 however the content is an ObjectType but I can't see an obvious way to retrieve the underlying exception to intelligently turn this into a bad request (or even a 404) and I also can't use standard logging framework to log the exception as I don't have the Exception object.

  Perhaps the way forward is to validate the GET and Body combination but this might not be the only error, ideally I'd like a reliable way to trap and log all exceptions being raised as strongly typed exceptions.

  It seems like Web API is trying to read the body but because no Content-Type header has been provided, it's failing.

  • Edited by LittleClive on Feb 23, 2012 08:39 AM
  • Edited by LittleClive on Feb 23, 2012 08:41 AM
  • Edited by LittleClive on Feb 23, 2012 08:43 AM