I am making a POST request using the System.Net.HttpWebRequest class and want to ensure that the request is well-formed just before I send it out.
So, I want to print out the entire request stream before it goes out.
I am looking at things in Fiddler but I am still interested in knowing if there is a way to programmatically read a request stream before it is sent out.
The trouble is that the request stream is not seekable, and it is not readable either. How do I read it?
So, this thing won't work:
...
accessTokenRequest.Method = "POST";
var accessTokenRequestStream = accessTokenRequest.GetRequestStream();
accessTokenRequestStream.Write(buffer, 0, buffer.Length);
accessTokenRequestStream.Seek(0, SeekOrigin.Begin);
using (var reader = new StreamReader(accessTokenRequestStream))
{
var requestText = reader.ReadToEnd();
Debugger.Break();
Debug.Print(requestText);
}
accessTokenRequestStream.Close();
The request stream is write-only, there is no way to read it.
What you can do, however, is prepare the request body in a MemoryStream, then rewind the MemoryStream and copy it to the request stream.
Related
I appreciate this is a little bit niche, but I thought I would ask anyway. I'm writing a small c# application to utilise the HMRC web portal and electronically submit VAT returns in XML format. According to the HMRC specification it is just a simple Http 1.1 POST action required, and retrieving the response in XML. The application is built, however, I am having trouble with this code. I get an "OK" HttpWebResponse, but the HMRC server returns this spurious error message which they can't seem to tell me what it means. Here is my code:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destinationUrl);
byte[] bytes;
bytes = System.Text.Encoding.ASCII.GetBytes(requestXml);
request.ContentType = "text/xml; charset='utf-8'";
request.ContentLength = bytes.Length;
request.Method = "POST";
Stream requestStream = request.GetRequestStream();
requestStream.Write(bytes, 0, bytes.Length);
requestStream.Close();
HttpWebResponse response;
response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
{
Stream responseStream = response.GetResponseStream();
string responseStr = new StreamReader(responseStream).ReadToEnd();
return responseStr;
}
And the error is:
1001 - The submitted XML document either failed to validate against the GovTalk schema for this class of document or its body was badly formed.
I know the XML is ok, because when I test it using a third-party tool like "Postman" it submits 100% and the Transaction Engine returns no errors, so it must be my code. Does anything look glaringly wrong to post an XML? I have tried different Content/MIME Types and also I have confirmed that 'utf-8' is the correct encoding.
I was just wondering if any developers out there had worked on the Transaction Engine and could share their submit/post code?
The answer is that the code converting the file contents into the Byte Array was actually converting the file name.
I changed this line:
bytes = System.Text.Encoding.ASCII.GetBytes(requestXml);
To this:
bytes = File.ReadAllBytes(requestXml);
how would I be able to do something like http://myanimelist.net/modules.php?go=api#verifycred
aka "curl -u user:password http://myanimelist.net/api/account/verify_credentials.xml"
I wish to option the id
my code so far is
string url = "http://myanimelist.net/api/account/verify_credentials.xml";
WebRequest request = WebRequest.Create(url);
request.ContentType = "xml";
request.Method = "GET";
request.Credentials = new NetworkCredential(username, password);
byte[] buffer = Encoding.GetEncoding("UTF-8").GetBytes("xml/user/id"); // i think this line?
Stream reqstr = request.GetRequestStream();
reqstr.Write(buffer, 0, buffer.Length);
reqstr.Close();
but I get a error on "reqstr.Write(buffer, 0, buffer.Length)"
Cannot send a content-body with this verb-type, I have tried googling but with no prevail, I am using c#
Your snippet is trying to send a GET request with request data (you're calling GetRequestStream and then writing some data to the request stream). The HTTP protocol does not allow this - you can only send data with POST request.
However, the API that you are trying to call is actually doing something different - you do not need to send it the XML data. The XML data (with user ID and user name) is the response that you get when you successfully login.
So, instead of calling GetRequestStream and writing the XML data, you need to call GetResponse and then GetResponseStream to read the XML data!
I am calling a web-service with POST and receiving a 2MB xml.
The problem is that it takes to much time until i can use the data within the Stream.
The response seems to be after 7 secs there, but it takes another 10 sec to read the content(its a string) from response stream.
Stopwatch s = new Stopwatch();
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(MyUri);
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = Poststring.Length;
s.Start();
StreamWriter swriter = new StreamWriter(req.GetRequestStream());
swriter.Write(Poststring);
swriter.Close();
// Get the response. 7 sec
HttpWebResponse response = (HttpWebResponse)req.GetResponse();
s.Stop();
Debug.WriteLine("Talking to Web-Service: "+s.ElapsedMilliseconds);
s.Reset();
// Get the stream containing content returned by the server.
Stream dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);
// Read the content. 10 sec
XmlReader xmlReader = XmlReader.Create(dataStream);
s.Start();
XDocument xdoc = XDocument.Load(xmlReader);
s.Stop();
Debug.WriteLine("Convert stream to some useful data: "+s.ElapsedMilliseconds);
output in milliseconds
Talking to Web-Service: 6595
"Convert" stream to some useful data: 10772
Why does it take like 10 sec to read the content??
Is there stil some communication with the web-service or waiting for data when content is read? Its just a simple textfile (xml) with about 2MB. I thought that those 2 MB were transfered within the 6596 milliseconds. Because when i call that service with my browser, the xml content is shown in 6-7 sec.
The time for Talking to Web-Service is ok, but what is going on in those 10772 milliseconds?
Edit: The problem is stil there. I get different answers and they contradict each other.
Add following
httpWebRequest.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate");
httpWebRequest.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
resulting in:
Talking to Web-Service: 6595
"Convert" stream to some useful data: 256
Now i have the same performance like in a browser!
XDocument xdoc = XDocument.Load(response.GetResponseStream(), LoadOptions.None);
Avoid the XmlReader.Create and use the XDocument.Load(Stream, LoadOptions) overload.
http://msdn.microsoft.com/en-us/library/cc838321.aspx
GetResponse will not return the full response stream. GetResponse will send your request and return an HttpWebResponse object based on the header information from the response. HttpWebResponse also has an associated stream from which you can read the full response body. This is precisely what you are doing.
I suspect that the 7-second delay you are seeing when you call GetResponse is a delay on the server in generating the XML document and sending a response. The further 10-second delay on XmlReader.Create is from reading the response stream (ie, downloading the file).
Is the XML generated dynamically? 7 seconds is not a terribly long time for an HTTP response, depending of course on your server location, quality, etc.
I found this snippet of code here that allows you to log into a website and get the response from the logged in page. However, I'm having trouble understanding all the part of the code. I've tried my best to fill in whatever I understand so far. Hope you guys can fill in the blanks for me. Thanks
string nick = "mrbean";
string password = "12345";
//this is the query data that is getting posted by the website.
//the query parameters 'nick' and 'password' must match the
//name of the form you're trying to log into. you can find the input names
//by using firebug and inspecting the text field
string postData = "nick=" + nick + "&password=" + password;
// this puts the postData in a byte Array with a specific encoding
//Why must the data be in a byte array?
byte[] data = Encoding.ASCII.GetBytes(postData);
// this basically creates the login page of the site you want to log into
WebRequest request = WebRequest.Create("http://www.mrbeanandme.com/login/");
// im guessing these parameters need to be set but i dont why?
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
// this opens a stream for writing the post variables.
// im not sure what a stream class does. need to do some reading into this.
Stream stream = request.GetRequestStream();
// you write the postData to the website and then close the connection?
stream.Write(data, 0, data.Length);
stream.Close();
// this receives the response after the log in
WebResponse response = request.GetResponse();
stream = response.GetResponseStream();
// i guess you need a stream reader to read a stream?
StreamReader sr = new StreamReader(stream);
// this outputs the code to console and terminates the program
Console.WriteLine(sr.ReadToEnd());
Console.ReadLine();
A Stream is a sequence of bytes.
In order to use text with a Stream, you need to convert it into a sequence of bytes.
This can be done manually with the Encoding classes or automatically with StreamReader and StreamWriter. (which read and write strings to streams)
As stated in the documentation for GetRequestStream,
You must call the Stream.Close method to close the stream and release the connection for reuse. Failure to close the stream causes your application to run out of connections.
The Method and Content-* properties reflect the underlying HTTP protocol.
I would like to know two things about the following code:
HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
objRequest.Method = "POST";
objRequest.ContentLength = strPost.Length;
objRequest.ContentType = "application/x-www-form-urlencoded";
myWriter = new StreamWriter(objRequest.GetRequestStream());
myWriter.Write(strPost);
Here are my two questions:
- What is exactly a stream?
- The line myWriter.Write sends an Http Packet with the post information or to do that i have to use a method of HttpWebRequest class?
As already stated a Stream is the usual .NET equivalent of a buffer. It's also almost always used when doing any sort of IO, be it files, pipes, network. Usually to work with a stream you use either StreamReader or StreamWriter.
Your method should be sending a packet correctly. To read a response you would do a similar operation with GetResponseStream.
A stream in .NET can be regarded as kind of a buffer.
It is used in file/http/memory IO
The stream in this case is a buffer which will be sent over network. This buffer is sent when you use GetResponse function
http://msdn.microsoft.com/fr-fr/library/system.net.webresponse.getresponsestream%28VS.80%29.aspx