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How to upload a document via API to watson discovery services. ASP.net

I'm using the following API to upload a file to watson discovery services. I'm getting the response as unsupported file format, even though i have provided a valid type.
API:discovery service api
public async Task<ActionResult> Index()
{
using (var httpClient = new HttpClient())
{
//ADD BASIC AUTH
var authByteArray = Encoding.ASCII.GetBytes("{auth key}");
var authString = Convert.ToBase64String(authByteArray);
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", authString);
var text = string.Empty;
var uri = "https://gateway.watsonplatform.net/discovery/api/v1/environments/{envid}/collections/{collectionid}/documents?version=2017-11-07";
var content = new MultipartFormDataContent();
var bytes = System.IO.File.ReadAllBytes(Server.MapPath("~/Views/UploadDocument/civilwar-api1.html"));
var file = new StreamContent(new MemoryStream(bytes));
content.Headers.ContentType = MediaTypeHeaderValue.Parse("text/html");
content.Add(new StreamContent(new MemoryStream(bytes)), "file");
var response = await httpClient.PostAsync(uri, content);
var text1 = await response.Content.ReadAsStringAsync();
}
return View();
}
api response as :{
"code" : 415,
"error" : "Unsupported Media Type"
}

As you can see in Watson Developer Cloud, you can use the .NET SDK.
In this repository, you can see examples for using each service from Watson.
The method to add a document:
#region Documents
private void AddDocument()
{
Console.WriteLine(string.Format("\nCalling AddDocument()..."));
using (FileStream fs = File.OpenRead(_filepathToIngest))
{
var result = _discovery.AddDocument(_createdEnvironmentId, _createdCollectionId, _createdConfigurationId, fs as Stream, _metadata);
if (result != null)
{
Console.WriteLine(JsonConvert.SerializeObject(result, Formatting.Indented));
_createdDocumentId = result.DocumentId;
}
else
{
Console.WriteLine("result is null.");
}
}
}
See more about Watson Discovery.

try httpClient.DefaultRequestHeaders
.Accept
.Add(new MediaTypeWithQualityHeaderValue("application/json"));//ACCEPT header

Client code to upload file via ASP.NET MVC WebApi

I am trying to write code to upload file(s) by WinForm app to WebApi.
The WebApi code is like:
[HttpPost]
[Route("UploadEnvelope")]
[HostAuthentication(DefaultAuthenticationTypes.ExternalBearer)]
public Task<HttpResponseMessage> PostUploadEnvelope()
{
HttpRequestMessage request = this.Request;
if (!request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
string root = System.Web.HttpContext.Current.Server.MapPath("~/App_Data/uploads");
var provider = new MultipartFormDataStreamProvider(root);
var task = request.Content.ReadAsMultipartAsync(provider).ContinueWith<HttpResponseMessage>(o =>
{
foreach (MultipartFileData fileData in provider.FileData)
{
if (string.IsNullOrEmpty(fileData.Headers.ContentDisposition.FileName))
{
return Request.CreateResponse(HttpStatusCode.NotAcceptable, "This request is not properly formatted");
}
string fileName = fileData.Headers.ContentDisposition.FileName;
if (fileName.StartsWith("\"") && fileName.EndsWith("\""))
{
fileName = fileName.Trim('"');
}
if (fileName.Contains(#"/") || fileName.Contains(#"\"))
{
fileName = Path.GetFileName(fileName);
}
File.Move(fileData.LocalFileName, Path.Combine(root, fileName));
}
return new HttpResponseMessage()
{
Content = new StringContent("Files uploaded.")
};
}
);
return task;
}
But I am not sure how to call it and pass file in a client app.
static string UploadEnvelope(string filePath, string token, string url)
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
// How to pass file here ???
var response = client.GetAsync(url + "/api/Envelope/UploadEnvelope").Result;
return response.Content.ReadAsStringAsync().Result;
}
}
Any help or suggestion is welcome. Thanks in advance!

First you are using Get method which is used for reading. You have to use Post instead.
Try the following:
public static string UploadEnvelope(string filePath,string token, string url)
{
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
using (var content = new MultipartFormDataContent("Envelope" + DateTime.Now.ToString(CultureInfo.InvariantCulture)))
{
content.Add(new StreamContent(new MemoryStream(File.ReadAllBytes(filePath))), "filename", "filename.ext");
using (var message = await client.PostAsync(url + "/api/Envelope/UploadEnvelope", content))
{
var input = await message.Content.ReadAsStringAsync();
return "success";
}
}
}
}
Note: For a large file you have to change configuration on IIS web.config.

A method was called at an unexpected time in HttpClient MultipartFormDataContent

I have to post the multipart data to the server but I am getting below error
I am using the below code
public async static Task<string> HttpImagePostMethod(byte[] wInputData, string Uri, string path)
{
string result = string.Empty;
try
{
#region For Https (Secure) Api having SSL
var filter = new HttpBaseProtocolFilter();
filter.IgnorableServerCertificateErrors.Add(Windows.Security.Cryptography.Certificates.ChainValidationResult.Untrusted);
var client = new System.Net.Http.HttpClient(new WinRtHttpClientHandler(filter));
#endregion
MultipartFormDataContent requestContent = new MultipartFormDataContent();
// StreamContent content = new StreamContent(wInputData);
var content = new ByteArrayContent(wInputData);
content.Headers.ContentType = new MediaTypeHeaderValue("image/jpg");
requestContent.Add(content, "file", path);
requestContent.Headers.Add("X-API-Key", UrlFactory.X_API_Key_Value);
requestContent.Add(new StringContent("144"), "type");
HttpResponseMessage aResp = await client.PostAsync(UrlFactory.BaseUrl + Uri, requestContent);
if (aResp.IsSuccessStatusCode)
{
result = await aResp.Content.ReadAsStringAsync();
}
else
{
result = await aResp.Content.ReadAsStringAsync();
}
}
catch (Exception ex)
{
result = string.Empty;
}
return result;
}
I am getting error at this line
HttpResponseMessage aResp = await client.PostAsync(UrlFactory.BaseUrl + Uri, requestContent);
Due to this line
requestContent.Headers.Add("X-API-Key", UrlFactory.X_API_Key_Value);

Myself Answer this question maybe helpful to my other friends...
HttpRequestMessage httpRequest = new HttpRequestMessage();
httpRequest.Method = HttpMethod.Post;
httpRequest.RequestUri = new System.Uri(UrlFactory.BaseUrl + Uri);
httpRequest.Content = requestContent;
httpRequest.Headers.TryAddWithoutValidation("Content-Type", "application/x-www-form-urlencoded");
httpRequest.Headers.TryAddWithoutValidation("X-API-Key", UrlFactory.X_API_Key_Value);
Client(HttpClient) shouldn't contain any header, we declaring header in HttpRequestMessage

As the error message says, you're trying to set a header on the content but it doesn't belong there; your API token is a property of the request itself and not of its content.
Try adding that header to client.DefaultRequestHeaders instead.

Troubleshooting HTTPClient asynchronous POST and reading results

I have a problem post string to form and read. Problem is they get away but need to do so sophisticated and it was very fast. Absolutely perfect multithreaded or asynchronous. Thank you very for your help.
This is my code.
private static void AsyncDown()
{
const string url = "http://whois.sk-nic.sk/index.jsp";
const string req = "PREM-0001";
var client = new HttpClient();
var pairs = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("text", "PREM-0001")
};
FormUrlEncodedContent content = new FormUrlEncodedContent(pairs);
HttpResponseMessage response = client.PostAsync("http://whois.sk-nic.sk/index.jsp", content).Result;
if (response.IsSuccessStatusCode)
{
HttpContent stream = response.Content;
Task<string> data = stream.ReadAsStringAsync();
}
}

Taking a rough stab in the dark at what your problem is, I'd guess that you're having trouble reading the response of your call.
When the content is POSTed to the server,
HttpResponseMessage response
= client.PostAsync("http://whois.sk-nic.sk/index.jsp", content).Result;
if (response.IsSuccessStatusCode)
{
HttpContent stream = response.Content;
Task<string> data = stream.ReadAsStringAsync();
}
It does so asynchronously, so the code will continue execution even though the result is not (most likely) available yet. Checking response.IsSuccessStatusCode will thus not give you the behavior you're expecting.
Change your calls to look like this by adding the await keyword:
HttpResponseMessage response
= await client.PostAsync("http://whois.sk-nic.sk/index.jsp", content);
Then, change the reading of the stream to use await as well:
if (response.IsSuccessStatusCode)
{
var data = await response.Content.ReadAsStringAsync();
}
EDIT: got some await objects mixed up and have corrected the code listing.
edit 2: here is the complete LINQPad script that I used to successfully download an HTML page from the given URL.
var client = new HttpClient();
var pairs = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("text", "PREM-0001")
};
FormUrlEncodedContent content = new FormUrlEncodedContent(pairs);
HttpResponseMessage response = await client.PostAsync("http://whois.sk-nic.sk/index.jsp", content);
if (response.IsSuccessStatusCode)
{
var data = await response.Content.ReadAsStringAsync();
//data.Dump(); //uncomment previous if using LINQPad
}

Maybe the site has changed since last post but now the request parameter name is whois not text. If this was the case a year ago too that's why it didn't work.
Today site responds to get too, i.e. http://whois.sk-nic.sk/index.jsp?whois=PREM-0001
Full code with get:
private async Task<string> Get(string code)
{
using (var client = new HttpClient())
{
var requestUri = String.Format("http://whois.sk-nic.sk/index.jsp?whois={0}", code);
var data = await client.GetStringAsync(requestUri);
return data;
}
}
Full code with post:
private async Task<string> Post()
{
using (var client = new HttpClient())
{
var postData = new KeyValuePair<string, string>[]
{
new KeyValuePair<string, string>("whois", "PREM-0001"),
};
var content = new FormUrlEncodedContent(postData);
var response = await client.PostAsync("http://whois.sk-nic.sk/index.jsp", content);
if (!response.IsSuccessStatusCode)
{
var message = String.Format("Server returned HTTP error {0}: {1}.", (int)response.StatusCode, response.ReasonPhrase);
throw new InvalidOperationException(message);
}
var data = await response.Content.ReadAsStringAsync();
return data;
}
}
Or a parser could be used because I guess extracting the returned values is the final goal:
private void HtmlAgilityPack(string code)
{
var requestUri = String.Format("http://whois.sk-nic.sk/index.jsp?whois={0}", code);
var request = new HtmlWeb();
var htmlDocument = request.Load(requestUri);
var name = htmlDocument.DocumentNode.SelectSingleNode("/html/body/table[1]/tr[5]/td/table/tr[2]/td[2]").InnerText.Trim();
var organizations = htmlDocument.DocumentNode.SelectSingleNode("/html/body/table[1]/tr[5]/td/table/tr[3]/td[2]").InnerText.Trim();
}

Receiving JSON data back from HTTP request

I have a web request that is working properly, but it is just returning the status OK, but I need the object I am asking for it to return. I am not sure how to get the json value I am requesting. I am new to using the object HttpClient, is there a property I am missing out on? I really need the returning object. Thanks for any help
Making the call - runs fine returns the status OK.
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Accept
.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var responseMsg = client.GetAsync(string.Format("http://localhost:5057/api/Photo")).Result;
The api get method
//Cut out alot of code but you get the idea
public string Get()
{
return JsonConvert.SerializeObject(returnedPhoto);
}

If you are referring to the System.Net.HttpClient in .NET 4.5, you can get the content returned by GetAsync using the HttpResponseMessage.Content property as an HttpContent-derived object. You can then read the contents to a string using the HttpContent.ReadAsStringAsync method or as a stream using the ReadAsStreamAsync method.
The HttpClient class documentation includes this example:
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.GetAsync("http://www.contoso.com/");
response.EnsureSuccessStatusCode();
string responseBody = await response.Content.ReadAsStringAsync();

Building on #Panagiotis Kanavos' answer, here's a working method as example which will also return the response as an object instead of a string:
using System.Text;
using System.Net.Http;
using System.Threading.Tasks;
using Newtonsoft.Json; // Nuget Package
public static async Task<object> PostCallAPI(string url, object jsonObject)
{
try
{
using (HttpClient client = new HttpClient())
{
var content = new StringContent(jsonObject.ToString(), Encoding.UTF8, "application/json");
var response = await client.PostAsync(url, content);
if (response != null)
{
var jsonString = await response.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<object>(jsonString);
}
}
}
catch (Exception ex)
{
myCustomLogger.LogException(ex);
}
return null;
}
Keep in mind that this is only an example and that you'd probably would like to use HttpClient as a shared instance instead of using it in a using-clause.

Install this nuget package from Microsoft System.Net.Http.Json. It contains extension methods.
Then add using System.Net.Http.Json
Now, you'll be able to see these methods:
So you can now do this:
await httpClient.GetFromJsonAsync<IList<WeatherForecast>>("weatherforecast");
Source: https://www.stevejgordon.co.uk/sending-and-receiving-json-using-httpclient-with-system-net-http-json

I think the shortest way is:
var client = new HttpClient();
string reqUrl = $"http://myhost.mydomain.com/api/products/{ProdId}";
var prodResp = await client.GetAsync(reqUrl);
if (!prodResp.IsSuccessStatusCode){
FailRequirement();
}
var prods = await prodResp.Content.ReadAsAsync<Products>();

What I normally do, similar to answer one:
var response = await httpClient.GetAsync(completeURL); // http://192.168.0.1:915/api/Controller/Object
if (response.IsSuccessStatusCode == true)
{
string res = await response.Content.ReadAsStringAsync();
var content = Json.Deserialize<Model>(res);
// do whatever you need with the JSON which is in 'content'
// ex: int id = content.Id;
Navigate();
return true;
}
else
{
await JSRuntime.Current.InvokeAsync<string>("alert", "Warning, the credentials you have entered are incorrect.");
return false;
}
Where 'model' is your C# model class.

It's working fine for me by the following way -
public async Task<object> TestMethod(TestModel model)
{
try
{
var apicallObject = new
{
Id= model.Id,
name= model.Name
};
if (apicallObject != null)
{
var bodyContent = JsonConvert.SerializeObject(apicallObject);
using (HttpClient client = new HttpClient())
{
var content = new StringContent(bodyContent.ToString(), Encoding.UTF8, "application/json");
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
client.DefaultRequestHeaders.Add("access-token", _token); // _token = access token
var response = await client.PostAsync(_url, content); // _url =api endpoint url
if (response != null)
{
var jsonString = await response.Content.ReadAsStringAsync();
try
{
var result = JsonConvert.DeserializeObject<TestModel2>(jsonString); // TestModel2 = deserialize object
}
catch (Exception e){
//msg
throw e;
}
}
}
}
}
catch (Exception ex)
{
throw ex;
}
return null;
}

The code below is to access your HttpResponseMessage and extract your response from HttpContent.
string result = ret.Result.Content.ReadAsStringAsync().Result;
Convert your json in a structure according with your business
In my case BatchPDF is a complex object that it is being populated by result variable.
BatchPDF batchJson = JsonConvert.DeserializeObject<BatchPDF>(result);
return batchJson;