How can one issue multiple requests using the same service?
I have created a static httpWebRequest:
private static HttpWebRequest request;
//private static StreamReader streamReader;
//private StreamWriter streamWriter;
public CentralRestService2(LogFile log)
{
if (request == null)
{
request = (HttpWebRequest)WebRequest.Create("service address");
request.Method = "POST";
request.Accept = "*/*";
request.ContentType = "application/json";
request.Headers["Authorization"] = "username and password";
request.KeepAlive = true;
}
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
string body = new JavaScriptSerializer().Serialize(emailRequest);
streamWriter.Write(body);
}
using (var streamReader = new StreamReader(response.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
}
response.Close();
}
I get error messages including that the stream cannot be written to. The connection has unexpectedly closed. I can't seem to find the answer anywhere!
Don't create static HttpWebRequest.
Request does not represent a connection, but it uses ServicePointManager which manages underlying TCP connections for you.
Just create a new instance of HttpWebRequest every time you need to send a request.
UPDATE:
If you want to create a client for your service, you should use HttpClient instead:
// add reference to System.Net.Http and System.Net.Http.Formatting
using System.Net.Http;
// with a handler you can configure the client and its behavior
var handler = new HttpClientHandler();
var httpClient = new HttpClient(handler);
httpClient.BaseAddress = new Uri("service address");
httpClient.DefaultRequestHeaders.Add("Authorization", "username and password");
var response = await httpClient.PostAsJsonAsync(httpClient.BaseAddress, emailRequest);
Related
In C # application, when calling API interface, it often takes 15+ seconds to access. API is deployed in another network segment of intranet and needs to be accessed by proxy. Some one said that it was a DNS problem, try to setting the host, which has no effect.
Environment: Windows Server 2012 R2, IIS v8.5
Code Script:
private string PostHttp(string url, string authHeader, string requestBody)
{
var webRequest = System.Net.WebRequest.Create(url);
ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
byte[] data = System.Text.Encoding.UTF8.GetBytes(requestBody);
webRequest.Method = "POST";
webRequest.Headers.Add("Accept-Language", "zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3");
webRequest.Headers.Add("Accept-Encoding", "gzip, deflate");
webRequest.Headers.Add("Authorization", authHeader);
webRequest.ContentLength = data.Length;
webRequest.ContentType = "application/x-www-form-urlencoded";
System.Net.WebProxy proxy = new System.Net.WebProxy("http://myHttpProxyAddress", false);
proxy.Credentials = new System.Net.NetworkCredential("HttpProxyUser", "HttpProxyPassword");
webRequest.Proxy = proxy;
var writer = webRequest.GetRequestStream();
writer.Write(data, 0, data.Length);
writer.Close();
using (WebResponse webResponse = webRequest.GetResponse())
{
System.IO.StreamReader reader = null;
if (webResponse.Headers["Content-Encoding"] == "gzip")
reader = new System.IO.StreamReader(new GZipStream(webResponse.GetResponseStream(), CompressionMode.Decompress), System.Text.Encoding.UTF8);
else
reader = new System.IO.StreamReader(webResponse.GetResponseStream(), System.Text.Encoding.UTF8);
var result = reader.ReadToEnd();
reader.Close();
return result;
}
}
it's very difficult to point out by just hearing someone said one of the possibility (e.g DNS error) , try to use some http utility (e.g Curl) to check and measure that.
you can wrap the request above with below this guide and measure the timing detail.
How do I measure request and response times at once using cURL?
I need to allow redirection in my WebClient 'cause I've this url:
http://int.soccerway.com/national/algeria/ligue-2/c207/
when I add this in the browser I'll get a redirect to this:
http://int.soccerway.com/national/algeria/ligue-2/20172018/regular-season/r43168/
when I perform a request I execute this method:
public static string GetData(string url)
{
HttpWebRequest webReq = (HttpWebRequest)HttpWebRequest.Create(url);
try
{
webReq.CookieContainer = new CookieContainer();
webReq.Method = "GET";
webReq.AllowAutoRedirect = true;
webReq.MaximumAutomaticRedirections = 1;
using (WebResponse response = webReq.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
StreamReader reader = new StreamReader(stream);
return reader.ReadToEnd();
}
}
...
}
but this throws an exception:
Too many automatic redirects have been attempted
other threads suggest to add a cookie container, I did so but the error happen occurs again. How can I solve this?
I am making a call to a page on my site using webclient. I'm trying to get the result of the webpage put into a pdf so I am trying to get a string representation of the rendered page. The problem is that the request is not authenticated so all I get is a login screen. I have sent the UseDefaultCredentials property to true but I still get the same result. Below is a portion of my code:
WebClient webClient = new WebClient();
webClient.Encoding = Encoding.UTF8;
webClient.UseDefaultCredentials = true;
return Encoding.UTF8.GetString(webClient.UploadValues(link, "POST",form));
You need to give the WebClient object the credentials. Something like this...
WebClient client = new WebClient();
client.Credentials = new NetworkCredential("username", "password");
What kind of authentication are you using? If it's Forms authentication, then at best, you'll have to find the .ASPXAUTH cookie and pass it in the WebClient request.
At worst, it won't work.
Public Function getWeb(ByRef sURL As String) As String
Dim myWebClient As New System.Net.WebClient()
Try
Dim myCredentialCache As New System.Net.CredentialCache()
Dim myURI As New Uri(sURL)
myCredentialCache.Add(myURI, "ntlm", System.Net.CredentialCache.DefaultNetworkCredentials)
myWebClient.Encoding = System.Text.Encoding.UTF8
myWebClient.Credentials = myCredentialCache
Return myWebClient.DownloadString(myURI)
Catch ex As Exception
Return "Exception " & ex.ToString()
End Try
End Function
This helped me to call API that was using cookie authentication. I have passed authorization in header like this:
request.Headers.Set("Authorization", Utility.Helper.ReadCookie("AuthCookie"));
complete code:
// utility method to read the cookie value:
public static string ReadCookie(string cookieName)
{
var cookies = HttpContext.Current.Request.Cookies;
var cookie = cookies.Get(cookieName);
if (cookie != null)
return cookie.Value;
return null;
}
// using statements where you are creating your webclient
using System.Web.Script.Serialization;
using System.Net;
using System.IO;
// WebClient:
var requestUrl = "<API_url>";
var postRequest = new ClassRoom { name = "kushal seth" };
using (var webClient = new WebClient()) {
JavaScriptSerializer serializer = new JavaScriptSerializer();
byte[] requestData = Encoding.ASCII.GetBytes(serializer.Serialize(postRequest));
HttpWebRequest request = WebRequest.Create(requestUrl) as HttpWebRequest;
request.Method = "POST";
request.ContentType = "application/json";
request.ContentLength = requestData.Length;
request.ContentType = "application/json";
request.Expect = "application/json";
request.Headers.Set("Authorization", Utility.Helper.ReadCookie("AuthCookie"));
request.GetRequestStream().Write(requestData, 0, requestData.Length);
using (var response = (HttpWebResponse)request.GetResponse()) {
var reader = new StreamReader(response.GetResponseStream());
var objText = reader.ReadToEnd(); // objText will have the value
}
}
I'm working with JSON and C# ( HttpWebRequest ). Basically I have application to download a JSON from and API REST, but the problem is when I download it, the JSON comes missing some data, it seems that is cutting some data, with wrong structure. If I use a software which does the same thing that I'm developing, this problem doesn't happen. I'm sure that is something with my code, if I'm missing something. Here is my code:
var httpWebRequest = (HttpWebRequest)WebRequest.Create("MyURL");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "GET";
string authInfo = "user" + ":" + "pass";
authInfo = Convert.ToBase64String(Encoding.Default.GetBytes(authInfo));
httpWebRequest.Headers["Authorization"] = "Basic " + authInfo;
// Create the HttpContent for the form to be posted.
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var sr = new StreamReader(httpResponse.GetResponseStream(), Encoding.UTF8))
{
StreamWriter sw = new StreamWriter(#"C:\test\Stores.txt");
sw.Write(sr.ReadToEnd());
}
You can try this.its works in my code.
public static async Task MethodName()
{
using (HttpClientHandler handler = new HttpClientHandler() { UseCookies = false })
{
using (HttpClient httpClient = new HttpClient(handler))
{
httpClient.DefaultRequestHeaders.Authorization = Program.getAuthenticationHeader();
string filterQuery = Program.getURI().ToString();
using (HttpResponseMessage httpResponse = await httpClient.GetAsync(filterQuery).ConfigureAwait(false))
{
var streamContent = await httpResponse.Content.ReadAsStreamAsync();
FileStream fs = new FileStream("C:\test\Stores.Json", FileMode.Create);
streamContent.CopyTo(fs);
streamContent.Close();
fs.Close();
}
}
}
}
This can be an issue with your Http request (GET).
Step 1 - If you have a working software with the API, use Fiddler to analyse what is the http GET request it sends. You need to check the header info as well.
Step 2 - Compare the Http request with the HttpRequest you have created. There can be missing parameters etc.
I am making a call to a page on my site using webclient. I'm trying to get the result of the webpage put into a pdf so I am trying to get a string representation of the rendered page. The problem is that the request is not authenticated so all I get is a login screen. I have sent the UseDefaultCredentials property to true but I still get the same result. Below is a portion of my code:
WebClient webClient = new WebClient();
webClient.Encoding = Encoding.UTF8;
webClient.UseDefaultCredentials = true;
return Encoding.UTF8.GetString(webClient.UploadValues(link, "POST",form));
You need to give the WebClient object the credentials. Something like this...
WebClient client = new WebClient();
client.Credentials = new NetworkCredential("username", "password");
What kind of authentication are you using? If it's Forms authentication, then at best, you'll have to find the .ASPXAUTH cookie and pass it in the WebClient request.
At worst, it won't work.
Public Function getWeb(ByRef sURL As String) As String
Dim myWebClient As New System.Net.WebClient()
Try
Dim myCredentialCache As New System.Net.CredentialCache()
Dim myURI As New Uri(sURL)
myCredentialCache.Add(myURI, "ntlm", System.Net.CredentialCache.DefaultNetworkCredentials)
myWebClient.Encoding = System.Text.Encoding.UTF8
myWebClient.Credentials = myCredentialCache
Return myWebClient.DownloadString(myURI)
Catch ex As Exception
Return "Exception " & ex.ToString()
End Try
End Function
This helped me to call API that was using cookie authentication. I have passed authorization in header like this:
request.Headers.Set("Authorization", Utility.Helper.ReadCookie("AuthCookie"));
complete code:
// utility method to read the cookie value:
public static string ReadCookie(string cookieName)
{
var cookies = HttpContext.Current.Request.Cookies;
var cookie = cookies.Get(cookieName);
if (cookie != null)
return cookie.Value;
return null;
}
// using statements where you are creating your webclient
using System.Web.Script.Serialization;
using System.Net;
using System.IO;
// WebClient:
var requestUrl = "<API_url>";
var postRequest = new ClassRoom { name = "kushal seth" };
using (var webClient = new WebClient()) {
JavaScriptSerializer serializer = new JavaScriptSerializer();
byte[] requestData = Encoding.ASCII.GetBytes(serializer.Serialize(postRequest));
HttpWebRequest request = WebRequest.Create(requestUrl) as HttpWebRequest;
request.Method = "POST";
request.ContentType = "application/json";
request.ContentLength = requestData.Length;
request.ContentType = "application/json";
request.Expect = "application/json";
request.Headers.Set("Authorization", Utility.Helper.ReadCookie("AuthCookie"));
request.GetRequestStream().Write(requestData, 0, requestData.Length);
using (var response = (HttpWebResponse)request.GetResponse()) {
var reader = new StreamReader(response.GetResponseStream());
var objText = reader.ReadToEnd(); // objText will have the value
}
}