How do enable a .Net web-API to accept g-ziped posts

Question

I have a fairly bog standard .net MVC 4 Web API application.

 public class LogsController : ApiController
{

    public HttpResponseMessage PostLog(List<         


        

Answer 1

I had the same requirement to POST gzipped data to a .NET web api controller. I came up with this solution:

public class GZipToJsonHandler : DelegatingHandler
{
    protected override Task SendAsync(HttpRequestMessage request,
                                                           CancellationToken cancellationToken)
    {
        // Handle only if content type is 'application/gzip'
        if (request.Content.Headers.ContentType == null ||
            request.Content.Headers.ContentType.MediaType != "application/gzip")
        {
            return base.SendAsync(request, cancellationToken);
        }

        // Read in the input stream, then decompress in to the outputstream.
        // Doing this asynronously, but not really required at this point
        // since we end up waiting on it right after this.
        Stream outputStream = new MemoryStream();
        Task task = request.Content.ReadAsStreamAsync().ContinueWith(t =>
            {
                Stream inputStream = t.Result;
                var gzipStream = new GZipStream(inputStream, CompressionMode.Decompress);

                gzipStream.CopyTo(outputStream);
                gzipStream.Dispose();

                outputStream.Seek(0, SeekOrigin.Begin);
            });

        // Wait for inputstream and decompression to complete. Would be nice
        // to not block here and work async when ready instead, but I couldn't 
        // figure out how to do it in context of a DelegatingHandler.
        task.Wait();

        // This next section is the key...

        // Save the original content
        HttpContent origContent = request.Content;

        // Replace request content with the newly decompressed stream
        request.Content = new StreamContent(outputStream);

        // Copy all headers from original content in to new one
        foreach (var header in origContent.Headers)
        {
            request.Content.Headers.Add(header.Key, header.Value);
        }

        // Replace the original content-type with content type
        // of decompressed data. In our case, we can assume application/json. A
        // more generic and reuseable handler would need some other 
        // way to differentiate the decompressed content type.
        request.Content.Headers.Remove("Content-Type");
        request.Content.Headers.Add("Content-Type", "application/json");

        return base.SendAsync(request, cancellationToken);
    }
}

Using this approach, the existing controller, which normally works with JSON content and automatic model binding, continued to work without any changes.

I'm not sure why the other answer was accepted. It provides a solution for handling the responses (which is common), but not requests (which is uncommon). The Accept-Encoding header is used to specify acceptable response encodings, and is not related to request encodings.