I'm using the REST API of OneDrive in my WCF Web Service. Everything works well but the Download of a file. I need to get the Stream object of the file downloaded but MemoryStream class gives me an Exception about ReadTimeout and WriteTimeout.
This is the code:
.... some code ....
var rClient = new RestClient("https://apis.live.net/v5.0/");
var rRequest = new RestRequest(rootFile.id + "/content", Method.GET);
rRequest.AddParameter("access_token", data.accessToken);
var rResponse = rClient.Execute(rRequest); // THE RESPONSE IS OK
byte[] array = rResponse.RawBytes;
Stream stream = new MemoryStream(array); // PROBLEM HERE!
return stream;
So when I create the Stream Object the MemoryStream throw 2 Exception on the fields ReadTimeout and WriteTimeout saying that they are not supported for this stream.
I don't know how to solve it
As suggested by Will in the comment, I discovered that the Exception on ReadTimeout and WriteTimeout was not the real problem. The Exception was thrown by a null object in the caller method, after the code posted above.
Below there is the point where the Exception was thrown: the Current object was null.
stream = client.DownloadFile(token);
if (stream != null)
{
**WebOperationContext.Current.OutgoingResponse.ContentType = "text/octet-stream";** //HERE
return stream;
}
I removed the line and everything was fixed
Related
I try to get a Base64 from a image-URL in my hosted Blazor Webassambly. The URL contains a link to a picture.
using (var client = new HttpClient())
{
var bytes = await client.GetByteArrayAsync(url); // there are other methods if you want to get involved with stream processing etc
var base64String = Convert.ToBase64String(bytes);
return base64String;
}
Throws Exception:
TypeError: Failed to fetch
The Exception is thrown with any client method.
var result = await client.[X](url);
Why its impossible to make a request with he http client?
I would try it with first retrieving the link to the picture and then downloading the bytes from there.
string pictureLink = await client.GetStringAsync(url);
var base64String = Convert.ToBase64String(await client.GetByteArrayAsync(pictureLink));
I am in a situation where when I get an HTTP 400 code from the server, it is a completely legal way of the server telling me what was wrong with my request (using a message in the HTTP response content)
However, the .NET HttpWebRequest raises an exception when the status code is 400.
How do I handle this? For me a 400 is completely legal, and rather helpful. The HTTP content has some important information but the exception throws me off my path.
It would be nice if there were some way of turning off "throw on non-success code" but if you catch WebException you can at least use the response:
using System;
using System.IO;
using System.Web;
using System.Net;
public class Test
{
static void Main()
{
WebRequest request = WebRequest.Create("http://csharpindepth.com/asd");
try
{
using (WebResponse response = request.GetResponse())
{
Console.WriteLine("Won't get here");
}
}
catch (WebException e)
{
using (WebResponse response = e.Response)
{
HttpWebResponse httpResponse = (HttpWebResponse) response;
Console.WriteLine("Error code: {0}", httpResponse.StatusCode);
using (Stream data = response.GetResponseStream())
using (var reader = new StreamReader(data))
{
string text = reader.ReadToEnd();
Console.WriteLine(text);
}
}
}
}
}
You might like to encapsulate the "get me a response even if it's not a success code" bit in a separate method. (I'd suggest you still throw if there isn't a response, e.g. if you couldn't connect.)
If the error response may be large (which is unusual) you may want to tweak HttpWebRequest.DefaultMaximumErrorResponseLength to make sure you get the whole error.
I know this has already been answered a long time ago, but I made an extension method to hopefully help other people that come to this question.
Code:
public static class WebRequestExtensions
{
public static WebResponse GetResponseWithoutException(this WebRequest request)
{
if (request == null)
{
throw new ArgumentNullException("request");
}
try
{
return request.GetResponse();
}
catch (WebException e)
{
if (e.Response == null)
{
throw;
}
return e.Response;
}
}
}
Usage:
var request = (HttpWebRequest)WebRequest.CreateHttp("http://invalidurl.com");
//... (initialize more fields)
using (var response = (HttpWebResponse)request.GetResponseWithoutException())
{
Console.WriteLine("I got Http Status Code: {0}", response.StatusCode);
}
Interestingly, the HttpWebResponse.GetResponseStream() that you get from the WebException.Response is not the same as the response stream that you would have received from server. In our environment, we're losing actual server responses when a 400 HTTP status code is returned back to the client using the HttpWebRequest/HttpWebResponse objects. From what we've seen, the response stream associated with the WebException's HttpWebResponse is generated at the client and does not include any of the response body from the server. Very frustrating, as we want to message back to the client the reason for the bad request.
I had similar issues when trying to connect to Google's OAuth2 service.
I ended up writing the POST manually, not using WebRequest, like this:
TcpClient client = new TcpClient("accounts.google.com", 443);
Stream netStream = client.GetStream();
SslStream sslStream = new SslStream(netStream);
sslStream.AuthenticateAsClient("accounts.google.com");
{
byte[] contentAsBytes = Encoding.ASCII.GetBytes(content.ToString());
StringBuilder msg = new StringBuilder();
msg.AppendLine("POST /o/oauth2/token HTTP/1.1");
msg.AppendLine("Host: accounts.google.com");
msg.AppendLine("Content-Type: application/x-www-form-urlencoded");
msg.AppendLine("Content-Length: " + contentAsBytes.Length.ToString());
msg.AppendLine("");
Debug.WriteLine("Request");
Debug.WriteLine(msg.ToString());
Debug.WriteLine(content.ToString());
byte[] headerAsBytes = Encoding.ASCII.GetBytes(msg.ToString());
sslStream.Write(headerAsBytes);
sslStream.Write(contentAsBytes);
}
Debug.WriteLine("Response");
StreamReader reader = new StreamReader(sslStream);
while (true)
{ // Print the response line by line to the debug stream for inspection.
string line = reader.ReadLine();
if (line == null) break;
Debug.WriteLine(line);
}
The response that gets written to the response stream contains the specific error text that you're after.
In particular, my problem was that I was putting endlines between url-encoded data pieces. When I took them out, everything worked. You might be able to use a similar technique to connect to your service and read the actual response error text.
Try this (it's VB-Code :-):
Try
Catch exp As WebException
Dim sResponse As String = New StreamReader(exp.Response.GetResponseStream()).ReadToEnd
End Try
An asynchronous version of extension function:
public static async Task<WebResponse> GetResponseAsyncNoEx(this WebRequest request)
{
try
{
return await request.GetResponseAsync();
}
catch(WebException ex)
{
return ex.Response;
}
}
This solved it for me:
https://gist.github.com/beccasaurus/929007/a8f820b153a1cfdee3d06a9c0a1d7ebfced8bb77
TL;DR:
Problem:
localhost returns expected content, remote IP alters 400 content to "Bad Request"
Solution:
Adding <httpErrors existingResponse="PassThrough"></httpErrors> to web.config/configuration/system.webServer solved this for me; now all servers (local & remote) return the exact same content (generated by me) regardless of the IP address and/or HTTP code I return.
I'm creating a .NET Core 3.1 web api method to download a pdf for a given filename. This method is shared across teams where their client code is generated using NSwag.
I recently changed produces attribute to Produces("Application/pdf") from json, this change is required so other teams can generate valid client code. However since this change, I haven't been able to download any files from this method. Requests to download documents return with a 406 error (in Postman) and the following error is logged to the server event viewer.
No output formatter was found for content types 'application/pdf, application/pdf' to write the response.
Reverting the produced content-type to 'application/json' does allow documents to be downloaded, but as mentioned, this value is required to be pdf.
Any suggestions would be greatly appreciated.
Method:
[HttpGet("{*filePath}")]
[ProducesResponseType(typeof(FileStreamResult), StatusCodes.Status200OK)]
[ProducesResponseType(StatusCodes.Status404NotFound)]
[ProducesResponseType(StatusCodes.Status400BadRequest)]
[ProducesResponseType(StatusCodes.Status401Unauthorized)]
[Produces("Application/pdf")]
public async Task<ActionResult> GetDocument(string fileName) {
RolesRequiredHttpContextExtensions.ValidateAppRole(HttpContext, _RequiredScopes);
var memoryStream = new MemoryStream();
var memoryStream = new MemoryStream();
using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read, bufferSize: 4096, useAsync: true)) {
stream.CopyTo(memoryStream);
}
memoryStream.Seek(offset: 0, SeekOrigin.Begin);
return new FileStreamResult(memoryStream, "Application/pdf");
}
I just came across the same error and after some investigation I found out that the cause of the exception was indeed in the model binding error. You already wrote about it in your answer, but on closer inspection it became obvious that the reason was not related to binding itself, rather to the response body.
Since you specified [Produces("application/pdf")] the framework assumes this content type is the only possible for this action, but when an exception is thrown, you get application/json containing error description instead.
So to make this work for both "happy path" and exceptions, you could specify multiple response types:
[Produces("application/pdf", "application/json")]
public async Task<ActionResult> GetDocument(string fileName)
{
...
}
I'am using
public asnyc Task<IActionResult> BuildPDF()
{
Stream pdfStream = _pdfService.GetData();
byte[] memoryContent = pdfStream.ToArray();
return File(memoryContent, "application/pdf");
}
and it works. Could you please try?
The issue was caused by renaming the method parameter and not updating [HttpGet("{*filePath}")] to [HttpGet("{*fileName}")]
I had the same error, it is very confusing in some cases.
I got this error after adding new parameter of type int[] to my method forgetting [FromQuery] attribute for it.
After adding [FromQuery] attribute error gone.
i'm having some problems implementing my WCF message interceptor. Basically i'm accessing the body contents and performing an xslt tranform over the nodeset to sort it alphabethicaly.
I've tested the XSLT stylesheet and it's working no problems. I write the result of the transform to a MemoryStream object and then attempt to recreate the message from the stream contents.
I examine the resulting stream using either a StreamReader or by loading it into an XmlDocument and i can see the the xml it contains it my expected result from the XSLT transform.
My problem occures when i try to recreate the message! I create an XmlReader based on the stream and use this as my body source for Message.CreateMessage(.....);
I cannot understand why i'm suddenly losing the "correct" contents in the stream when i could examine it and see a couple of statements earlier.
Help very much appreciated!
Full code of the method below:
public object AfterReceiveRequest(ref System.ServiceModel.Channels.Message request, IClientChannel channel, InstanceContext instanceContext)
{
MessageBuffer msgbuf = request.CreateBufferedCopy(int.MaxValue);
Message tmpMessage = msgbuf.CreateMessage();
XmlDictionaryReader xdr = tmpMessage.GetReaderAtBodyContents();
MemoryStream ms = new MemoryStream();
_compiledTransform.Transform(xdr,null,ms);
ms.Position = 0;
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(ms);
MemoryStream newStream = new MemoryStream();
xmlDoc.Save(newStream);
newStream.Position = 0;
//To debug contents of the stream
StreamReader sr = new StreamReader(newStream);
var temp = sr.ReadToEnd();
//At this point the XSLT tranforms has resulted in the fragment we want so all good!
XmlReaderSettings settings = new XmlReaderSettings();
settings.ConformanceLevel = ConformanceLevel.Fragment;
newStream.Position = 0;
XmlReader reader = XmlReader.Create(newStream,settings);
reader.MoveToContent();
//Reader seems to have lost the correct fragment!!! At least returned message does not contain correct fragment.
Message newMessage = Message.CreateMessage(request.Version, null, reader);
newMessage.Properties.CopyProperties(request.Properties);
request = newMessage;
return request;
}
I think your code works Griff. I've just plugged it into an existing an existing IDispatchMessageInspector implementation and it generated a good (transformed) message. I therefore suspect your problem lies elsewhere.
How are you establishing that the 'losing' the correct contents? Could whatever is inspecting the transformed message be reading the message prior to transformation by mistake?
Unless you are trying to correlate state with the BeforeSendReply method then you should be returning null instead of the request reference.
Greetings, all. Here is my situation. I am attempting to make an HttpWebRequest to a local handler file and I keep getting the following exception:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
Now, I'm using a local handler file because I am writing some integration code for a third party that the site will be using. Until I have a test environment available for me to make requests to, I'm basically mocking the process with a local handler file. Here is the relevant code. Thanks.
WebRequest code (subRequest variable is object passed to the method executing this code):
XmlSerializer serializer;
XmlDocument xmlDoc = null;
HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(requestUrl);
webRequest.Method = "POST";
webRequest.ContentType = "text/xml";
webRequest.KeepAlive = true;
webRequest.Accept = "*/*";
serializer = new XmlSerializer(subRequest.GetType());
XmlWriter writer = new XmlTextWriter(webRequest.GetRequestStream(), Encoding.UTF8);
serializer.Serialize(writer, subRequest);
writer.Close();
xmlDoc = new XmlDocument();
xmlDoc.Load(XmlReader.Create(webRequest.GetResponse().GetResponseStream()));
The "requestUrl" is defined as "http://localhost:2718/Handlers/MyHandler.ashx". I can hit the handler file just fine and have stepped through the code. All it does is assemble an XML response as a string and writes it out to the Response object:
context.Response.ContentType = "text/xml";
string newSubscriptionId = Utils.GetUniqueKey();
StringBuilder sb = new StringBuilder();
sb.Append("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
// Assemble XML string here
context.Response.Write(sb.ToString());
As far as I can tell, this is all working just fine. But when my code hits the last line of the WebRequest chunk:
xmlDoc.Load(XmlReader.Create(webRequest.GetResponse().GetResponseStream()));
Is when the exception is thrown. Any ideas? Thanks in advance.
James
First, if you don't intend to reuse the connection or there's not going to be another request to the same schema/server/port, I would set KeepAlive to false.
The problem is that XmlDocument.Load() does not read the entire stream before the server closes the connection or that it keeps reading beyond the end and when the server keep-alive timeout is over, the connection is closed by the server. Also, you never close the response stream. To verify that this theory is correct, do something like:
// Optional -> webRequest.KeepAlive = false;
string xml = null;
using (StreamReader reader = new StreamReader (webRequest.GetResponse().GetResponseStream())) {
xml = reader.ReadToEnd ();
}
xmlDoc.LoadXml (xml);
and see if that fixes your problem.