In a C# Windows Forms application I can get the contents of a webpage using:
string content = webClient.DownloadString(url);
And I can get the HTTP header using:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
string response = ((HttpWebResponse)request.GetResponse()).StatusCode.ToString();
Is there a way to get both the contents and the HTTP status code (if it fails) in one trip to the server instead of twice?
Thanks.
You can read the data from the Stream inside the HttpWebResponse object:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
using (var reader = new StreamReader(stream))
{
HttpStatusCode statusCode = ((HttpWebResponse)response).StatusCode;
string contents = reader.ReadToEnd();
}
In this way you will have to detect the encoding by hand, or using a library to detect encoding. You can read the encoding as a string from the HttpWebResponse object as well, when one exists, it is inside the ContentType property. If the page is Html, then you will have to parse it for a possible encoding change in the top of the document or inside the head.
Read handling the encoding from ContentType header
var request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
string content;
HttpStatusCode statusCode;
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
{
var contentType = response.ContentType;
Encoding encoding = null;
if (contentType != null)
{
var match = Regex.Match(contentType, #"(?<=charset\=).*");
if (match.Success)
encoding = Encoding.GetEncoding(match.ToString());
}
encoding = encoding ?? Encoding.UTF8;
statusCode = ((HttpWebResponse)response).StatusCode;
using (var reader = new StreamReader(stream, encoding))
content = reader.ReadToEnd();
}
WebClient
I assume you use WebClient because its easy webrequest-to-string handling. Unfortunately, WebClient does not expose the HTTP response code. You can either assume the response was positive (2xx) unless you get an exception and read it:
try
{
string content = webClient.DownloadString(url);
}
catch (WebException e)
{
HttpWebResponse response = (System.Net.HttpWebResponse)we.Response;
var statusCode = response.StatusCode;
}
Or if you're really interested in the success code you can use reflection as explained here.
HttpClient
You can also use HttpClient if you're on .NET 4.5, which does expose the response code, as explained here:
using (HttpClient client = new HttpClient())
{
HttpResponseMessage response = await client.GetAsync(url);
string content = await response.Content.ReadAsStringAsync();
var statusCode = response.StatusCode;
}
HttpWebRequest
Alternatively, you can just use HttpWebRequest to get the status and response as explained here:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
var response = (HttpWebResponse)request.GetResponse();
using (Stream stream = response.GetResponseStream())
{
StreamReader reader = new StreamReader(stream);
string content = reader.ReadToEnd();
var statusCode = response.StatusCode;
}
I think, you have not realised, that in the second case you have access to the content as well (although it takes a little more effort to get as a string).
Look at the Microsoft documentation: http://msdn.microsoft.com/en-us/library/system.net.httpwebresponse.getresponsestream(v=vs.110).aspx which shows you how to ge a response stream from the web response, and then how to get the string data from that stream.
And I can get the HTTP header using:
request.Method = "GET";
Method GET returns HEAD and BODY sections in response.
HTTP also support a method HEAD - which returns HEAD section only.
You can get BODY from HttpWebResponse using GetResponseStream method.
Related
I try to convert HttpWebRequest to HttpClient but without success.
Can anybody help me?
It is my simple code with HttpWebRequest:
string url = "https://www.somesite.com/Service";
string postData = "text to send";
var data = Encoding.ASCII.GetBytes(postData);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "POST";
request.Proxy = null;
request.AllowAutoRedirect = false;
request.UserAgent = "Mozilla/5.0";
request.ContentType = "text/x-gwt-rpc; charset=UTF-8";
request.Headers.Add("Cookie", SetCookie);//get it after login
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string responseText = reader.ReadToEnd();
I think you can convert you HttpWebRequest based code to HttpClient based like this:
string url = "https://www.somesite.com/Service";
string postData = "text to send";
var data = Encoding.ASCII.GetBytes(postData);
var content = new ByteArrayContent(data);
using var httpHandler = new HttpClientHandler { UseCookies = false, AllowAutoRedirect = false };
using var client = new HttpClient(httpHandler);
client.DefaultRequestHeaders.Add("UserAgent","Mozilla/5.0");
client.DefaultRequestHeaders.Add("ContentType", "text/x-gwt-rpc; charset=UTF-8");
client.DefaultRequestHeaders.Add("Cookie", SetCookie);
using var requestMessage = new HttpRequestMessage(HttpMethod.Post, url) { Content = content };
var response = await client.SendAsync(requestMessage);
var responseText = await response.Content.ReadAsStringAsync();
Remarks:
Instead of writing the Request's Stream manually you can use the ByteArrayContent abstraction for this. (Related SO topic)
In order to set the cookie(s) manually you have to turn-off the default behaviour. You can do this via the HttpClientHandler's UseCookies. (Related SO topic)
To set the headers manually you can use the HttpClient's DefaultRequestHeaders (Related SO topic)
The counterpart of GetResponse is the SendAsync
Instead of reading the Response's Stream manually you can use the HttpContent's ReadAsStringAsync (Related SO topic)
UPDATE: Include OP's amended code
var content = new StringContent(postData, Encoding.UTF8, "text/x-gwt-rpc");
So, instead of ByteArrayContent StringContent is being used.
My remote server is throwing a web exception as bad request. But I know there is more information included in the error than what I get. If I look at the details from the exception it does not list the actual content of the response. I can see the content-type, content-length and content-encoding only. If I run this same message through another library (such as restsharp) I will see detailed exception information from the remote server. How can I get more details from the response since I know the remote server is sending them?
static string getXMLString(string xmlContent, string url)
{
//string Url;
string sResult;
//Url = ConfigurationManager.AppSettings["UserURl"] + url;
var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
httpWebRequest.ContentType = "application/xml";
httpWebRequest.Method = "POST";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
streamWriter.Write(xmlContent);
streamWriter.Flush();
streamWriter.Close();
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
sResult = result;
}
}
return sResult;
}
EDIT : Have you tried with a simple try-catch to see if you can get more details ?
try
{
var response = (HttpWebResponse)(request.GetResponse());
}
catch(Exception ex)
{
var response = (HttpWebResponse)ex.Response;
}
In my recherches in an answer for you, I noticed that in code there was something about encoding, that you didn't specified. Look here for exemple with such code.
var encoding = ASCIIEncoding.ASCII;
using (var reader = new System.IO.StreamReader(response.GetResponseStream(), encoding))
{
string responseText = reader.ReadToEnd();
}
Or here, in the doc, also.
// Creates an HttpWebRequest with the specified URL.
HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create(url);
// Sends the HttpWebRequest and waits for the response.
HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
// Gets the stream associated with the response.
Stream receiveStream = myHttpWebResponse.GetResponseStream();
Encoding encode = System.Text.Encoding.GetEncoding("utf-8");
// Pipes the stream to a higher level stream reader with the required encoding format.
StreamReader readStream = new StreamReader( receiveStream, encode );
Console.WriteLine("\r\nResponse stream received.");
Have you tried with such ?
I am working with GoogleApi. I want to get accesstoken as response using Google api. when I am sending httpwebrequest for getting access token then
When I used :- request.Method = "POST"
Exception:- HTTP method POST is not supported by this URL
When I used :- request.Method = "GET"
Exception:- System.Net.ProtocolViolationException: Cannot send a content-body with this verb-type
The actual request might look like:
POST /o/oauth2/token HTTP/1.1
Host: accounts.google.com
Content-Type: application/x-www-form-urlencoded
code=4/P7q7W91a-oMsCeLvIaQm6bTrgtp7&
client_id=8819981768.apps.googleusercontent.com&
client_secret={client_secret}&
redirect_uri=https://oauth2-login-demo.appspot.com/code&
grant_type=authorization_code
A successful response is returned as a JSON array, similar to the following:
{
"access_token":"1/fFAGRNJru1FTz70BzhT3Zg",
"expires_in":3920,
"token_type":"Bearer"
}
My Code is :-
var request = (HttpWebRequest)WebRequest.Create(#"https://accounts.google.com");
request.Method = "POST";
request.ContentType = "application/json";
//request.KeepAlive = false;
// request.Headers[HttpRequestHeader.Authorization] = "";
//request.ContentLength = 0;
using (StreamWriter streamWriter = new StreamWriter(request.GetRequestStream()))
{
string json = "{\"code\":\"4/M1IIC8htCuvYORuVJK16oadDb3Gd.cigIKgaPjvUYXE-sT2ZLcbSrckCLgwI\"," + "\"client_id\":\"841994137170.apps.googleusercontent.com\"," + "\"client_secret\":\"MXjKvevD_cKp5eQWZ1RFXfdo\"," + "\"redirect_uri\":\"http://gmailcheck.com/response.aspx\"," + "\"grant_type\":\"authorization_code\"}";
streamWriter.Write(json);
// streamWriter.Flush();
//streamWriter.Close();
}
try
{
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
StreamReader responsereader = new StreamReader(response.GetResponseStream());
var responsedata = responsereader.ReadToEnd();
//Session["responseinfo"] = responsereader;
}
}
catch (WebException ex)
{
using (WebResponse response = ex.Response)
{
var httpResponse = (HttpWebResponse)response;
using (Stream data = response.GetResponseStream())
{
var sr = new StreamReader(data);
throw new Exception(sr.ReadToEnd());
}
}
}
This is the problem:
var request = (HttpWebRequest)WebRequest.Create(#"https://accounts.google.com");
That's not the URL you showed originally. That's just the domain root. You need:
var request = (HttpWebRequest)WebRequest.Create("https://accounts.google.com/o/oauth2/token");
I've removed the # as your string doesn't include any line breaks or backslashes, so there's no benefit in using a verbatim string literal.
(Additionally, I'd expect this to be covered in the Google Client APIs - is it not?)
I am trying to replicate a Couch database using .NET classes instead of a curl command line. I have never used WebRequest or Httpwebrequest before, but I am attempting to use them to make a post request with the script below.
Here is the JSON script for couchdb replication(I know this works):
{ ""_id"":"database_replicate8/7/12", "source":sourcedb, ""target"":"targetDB", ""create_target"":true, ""user_ctx"": { ""roles"": ["myrole"] } }
The above script is put into a text file, sourcefile.txt. I want to take this line and put it in a POST web request using .NET functionality.
After looking into it, I chose to use the httpwebrequest class. Below is what I have so far--I got this from http://msdn.microsoft.com/en-us/library/debx8sh9.aspx
HttpWebRequest bob = (HttpWebRequest)WebRequest.Create("sourceDBURL");
bob.Method = "POST";
bob.ContentType = "application/json";
byte[] bytearray = File.ReadAllBytes(#"sourcefile.txt");
Stream datastream = bob.GetRequestStream();
datastream.Write(bytearray, 0, bytearray.Length);
datastream.Close();
Am I going about this correctly? I am relatively new to web technologies and still learning how http calls work.
Here is a method I use for creating POST requests:
private static HttpWebRequest createNewPostRequest(string apikey, string secretkey, string endpoint)
{
HttpWebRequest request = WebRequest.Create(endpoint) as HttpWebRequest;
request.Proxy = null;
request.Method = "POST";
//Specify the xml/Json content types that are acceptable.
request.ContentType = "application/xml";
request.Accept = "application/xml";
//Attach authorization information
request.Headers.Add("Authorization", apikey);
request.Headers.Add("Secretkey", secretkey);
return request;
}
Within my main method I call it like this:
HttpWebRequest request = createNewPostRequest(apikey, secretkey, endpoint);
and I then pass my data to the method like this:
string requestBody = SerializeToString(requestObj);
byte[] byteStr = Encoding.UTF8.GetBytes(requestBody);
request.ContentLength = byteStr.Length;
using (Stream stream = request.GetRequestStream())
{
stream.Write(byteStr, 0, byteStr.Length);
}
//Parse the response
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
//Business error
if (response.StatusCode != HttpStatusCode.OK)
{
Console.WriteLine(string.Format("Error: response status code is{0}, at time:{1}", response.StatusCode, DateTime.Now.ToString()));
return "error";
}
else if (response.StatusCode == HttpStatusCode.OK)//Success
{
using (Stream respStream = response.GetResponseStream())
{
XmlSerializer serializer = new XmlSerializer(typeof(SubmitReportResponse));
reportReq = serializer.Deserialize(respStream) as SubmitReportResponse;
}
}
...
In my case I serialize/deserialize my body from a class - you will need to alter this to use your text file. If you want an easy drop in solution, then change the SerializetoString method to a method that loads your text file to a string.
HttpWebRequest request = WebRequest.Create("http://google.com") as HttpWebRequest;
request.Accept = "application/xrds+xml";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
WebHeaderCollection header = response.Headers;
Here google returns text. How to read it?
Your "application/xrds+xml" was giving me issues, I was receiving a Content-Length of 0 (no response).
After removing that, you can access the response using response.GetResponseStream().
HttpWebRequest request = WebRequest.Create("http://google.com") as HttpWebRequest;
//request.Accept = "application/xrds+xml";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
WebHeaderCollection header = response.Headers;
var encoding = ASCIIEncoding.ASCII;
using (var reader = new System.IO.StreamReader(response.GetResponseStream(), encoding))
{
string responseText = reader.ReadToEnd();
}
The accepted answer does not correctly dispose the WebResponse or decode the text. Also, there's a new way to do this in .NET 4.5.
To perform an HTTP GET and read the response text, do the following.
.NET 1.1 ‒ 4.0
public static string GetResponseText(string address)
{
var request = (HttpWebRequest)WebRequest.Create(address);
using (var response = (HttpWebResponse)request.GetResponse())
{
var encoding = Encoding.GetEncoding(response.CharacterSet);
using (var responseStream = response.GetResponseStream())
using (var reader = new StreamReader(responseStream, encoding))
return reader.ReadToEnd();
}
}
.NET 4.5
private static readonly HttpClient httpClient = new HttpClient();
public static async Task<string> GetResponseText(string address)
{
return await httpClient.GetStringAsync(address);
}
I've just tried that myself, and it gave me a 200 OK response, but no content - the content length was 0. Are you sure it's giving you content? Anyway, I'll assume that you've really got content.
Getting actual text back relies on knowing the encoding, which can be tricky. It should be in the Content-Type header, but then you've got to parse it etc.
However, if this is actually XML (e.g. from "http://google.com/xrds/xrds.xml"), it's a lot easier. Just load the XML into memory, e.g. via LINQ to XML. For example:
using System;
using System.IO;
using System.Net;
using System.Xml.Linq;
using System.Web;
class Test
{
static void Main()
{
string url = "http://google.com/xrds/xrds.xml";
HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url);
XDocument doc;
using (WebResponse response = request.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
doc = XDocument.Load(stream);
}
}
// Now do whatever you want with doc here
Console.WriteLine(doc);
}
}
If the content is XML, getting the result into an XML object model (whether it's XDocument, XmlDocument or XmlReader) is likely to be more valuable than having the plain text.
This article gives a good overview of using the HttpWebResponse object:How to use HttpWebResponse
Relevant bits below:
HttpWebResponse webresponse;
webresponse = (HttpWebResponse)webrequest.GetResponse();
Encoding enc = System.Text.Encoding.GetEncoding(1252);
StreamReader loResponseStream = new StreamReader(webresponse.GetResponseStream(),enc);
string Response = loResponseStream.ReadToEnd();
loResponseStream.Close();
webresponse.Close();
return Response;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://www.google.com");
request.Method = "GET";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);
string strResponse = reader.ReadToEnd();
response.GetResponseStream() should be used to return the response stream. And don't forget to close the Stream and Response objects.
If you http request is Post and request.Accept = "application/x-www-form-urlencoded";
then i think you can to get text of respone by code bellow:
var contentEncoding = response.Headers["content-encoding"];
if (contentEncoding != null && contentEncoding.Contains("gzip")) // cause httphandler only request gzip
{
// using gzip stream reader
using (var responseStreamReader = new StreamReader(new GZipStream(response.GetResponseStream(), CompressionMode.Decompress)))
{
strResponse = responseStreamReader.ReadToEnd();
}
}
else
{
// using ordinary stream reader
using (var responseStreamReader = new StreamReader(response.GetResponseStream()))
{
strResponse = responseStreamReader.ReadToEnd();
}
}