WCF Streaming File Transfer ON .NET 4

The following answers detail using a few techniques for a posting binary data to a restful service.

• Post binary data to a RESTful application
• What is a good way to transfer binary data to a HTTP REST API service?
• Bad idea to transfer large payload using web services?

The following code is a sample of how you could write a RESTful WCF service and is by no means complete but does give you an indication on where you could start.

Sample Service, note that this is NOT production ready code.

[ServiceContract] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)] public class FileService { private IncomingWebRequestContext m_Request; private OutgoingWebResponseContext m_Response; [WebGet(UriTemplate = "{appName}/{id}?action={action}")] public Stream GetFile(string appName, string id, string action) { var repository = new FileRepository(); var response = WebOperationContext.Current.OutgoingResponse; var result = repository.GetById(int.Parse(id)); if (action != null && action.Equals("download", StringComparison.InvariantCultureIgnoreCase)) { response.Headers.Add("Content-Disposition", string.Format("attachment; filename={0}", result.Name)); } response.Headers.Add(HttpResponseHeader.ContentType, result.ContentType); response.Headers.Add("X-Filename", result.Name); return result.Content; } [WebInvoke(UriTemplate = "{appName}", Method = "POST")] public void Save(string appName, Stream fileContent) { try { if (WebOperationContext.Current == null) throw new InvalidOperationException("WebOperationContext is null."); m_Request = WebOperationContext.Current.IncomingRequest; m_Response = WebOperationContext.Current.OutgoingResponse; var file = CreateFileResource(fileContent, appName); if (!FileIsValid(file)) throw new WebFaultException(HttpStatusCode.BadRequest); SaveFile(file); SetStatusAsCreated(file); } catch (Exception ex) { if (ex.GetType() == typeof(WebFaultException)) throw; if (ex.GetType().IsGenericType && ex.GetType().GetGenericTypeDefinition() == typeof(WebFaultException<>)) throw; throw new WebFaultException<string>("An unexpected error occurred.", HttpStatusCode.InternalServerError); } } private FileResource CreateFileResource(Stream fileContent, string appName) { var result = new FileResource(); fileContent.CopyTo(result.Content); result.ApplicationName = appName; result.Name = m_Request.Headers["X-Filename"]; result.Location = @"C:\SomeFolder\" + result.Name; result.ContentType = m_Request.Headers[HttpRequestHeader.ContentType] ?? this.GetContentType(result.Name); result.DateUploaded = DateTime.Now; return result; } private string GetContentType(string filename) { // this should be replaced with some form of logic to determine the correct file content type (I.E., use registry, extension, xml file, etc.,) return "application/octet-stream"; } private bool FileIsValid(FileResource file) { var validator = new FileResourceValidator(); var clientHash = m_Request.Headers[HttpRequestHeader.ContentMd5]; return validator.IsValid(file, clientHash); } private void SaveFile(FileResource file) { // This will persist the meta data about the file to a database (I.E., size, filename, file location, etc) new FileRepository().AddFile(file); } private void SetStatusAsCreated(FileResource file) { var location = new Uri(m_Request.UriTemplateMatch.RequestUri.AbsoluteUri + "/" + file.Id); m_Response.SetStatusAsCreated(location); } } 

Sample Client, note that this is NOT production ready code.

// ********************************* // Sample Client // ********************************* private void UploadButton_Click(object sender, EventArgs e) { var uri = "http://dev-fileservice/SampleApplication" var fullFilename = @"C:\somefile.txt"; var fileContent = File.ReadAllBytes(fullFilename); using (var webClient = new WebClient()) { try { webClient.Proxy = null; webClient.Headers.Add(HttpRequestHeader.ContentMd5, this.CalculateFileHash()); webClient.Headers.Add("X-DaysToKeep", DurationNumericUpDown.Value.ToString()); webClient.Headers.Add("X-Filename", Path.GetFileName(fullFilename)); webClient.UploadData(uri, "POST", fileContent); var fileUri = webClient.ResponseHeaders[HttpResponseHeader.Location]; Console.WriteLine("File can be downloaded at" + fileUri); } catch (Exception ex) { var exception = ex.Message; } } } private string CalculateFileHash() { var hash = MD5.Create().ComputeHash(File.ReadAllBytes(@"C:\somefile.txt")); var sb = new StringBuilder(); for (int i = 0; i < hash.Length; i++) { sb.Append(hash[i].ToString("x2")); } return sb.ToString(); } private void DownloadFile() { var uri = "http://dev-fileservice/SampleApplication/1" // this is the URL returned by the Restful file service using (var webClient = new WebClient()) { try { webClient.Proxy = null; var fileContent = webClient.DownloadData(uri); } catch (Exception ex) { MessageBox.Show(ex.Message); } } }