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API Call not successful

Good day Guys,
I am trying to Use an SMS API. Everything looks fine from my end but the SMS is not delivering. If i use the URL directly on Browser, it executes.
Or is anything wrong with how i built the string?
Below is the code.
Please Note tht cbo.Title is a comobox, txtFirstname is a Textbox.
public void NewText()
{
string username = "something#gmail.com";
string password = "Password";
string urlStr;
string message=" Dear " + cbo_Title.Text + " " + txt_FirstName.Text + ", Your New Savings Account Number is " + Account_No + ".Welcome to AGENTKUNLE Global Services. Your Future is Our Priority ";
string sender = "AGENTKUNLE";
string recipient=txt_Phone.Text;
urlStr = "https://portal.nigeriabulksms.com/api/?username="+username+"+password="+password+"+sender="+sender+"+message="+message+"+ mobiles="+recipient;
Uri success = new Uri(urlStr);
}

private string SendSms(string apiUrl)
{
var targetUri = new Uri(apiUrl);
var webRequest = (HttpWebRequest) WebRequest.Create(targetUri);
webRequest.Method = WebRequestMethods.Http.Get;
try
{
string webResponse;
using (var getresponse = (HttpWebResponse) webRequest.GetResponse())
{
var stream = getresponse.GetResponseStream();
if (stream != null)
using (var reader = new StreamReader(stream))
{
webResponse = reader.ReadToEnd();
reader.Close();
}
else
webResponse = null;
getresponse.Close();
}
if (!string.IsNullOrEmpty(webResponse?.Trim()))
return webResponse.Trim();
}
catch (WebException ex)
{
ErrorHelper.Log(ex);
}
catch (Exception ex)
{
ErrorHelper.Log(ex);
}
finally
{
webRequest.Abort();
}
return null;
}

You never make a request.
The Uri object is just a container for the uri (see Microsoft Docs).
Check out the HttpClient class if you want to send a request.

HttpWebRequest.GetRequestStream() stall after second attempt (asynch) c#

my environment version is 2.0, I am currently working with Unity 5.5, c#.
I am experiencing a stall the 3rd time i try to get an HttpWebRequest request stream.
What I want to achieve is having a mechanism of "retry": when I send a request I wait for the response and if it times out I send another request and refresh the time out. I stop this loop when I hit MAX_ATTEMPTS or one of the requests get a response (even if it is from a request that has timed out).
The code that handles this loop is here:
IEnumerator DoRequest()
{
List<IAsyncResult> results = new List<IAsyncResult>(MAX_ATTEMPTS);
int attemptNumber = 1;
while (attemptNumber <= MAX_ATTEMPTS)
{
IAsyncResult result = null;
try
{
result = SendRequest();
}
catch (Exception e)
{
ProcessException(e);
yield break;
}
if (result != null)
{
results.Add(result);
DateTime timeOutTime = DateTime.UtcNow + TIMEOUT;
yield return null;
while (DateTime.UtcNow < timeOutTime)
{
int completedIndex = -1;
if (IsAnyResultCompleted(results, out completedIndex) == true)
{
ProcessResponse(results[completedIndex]);
yield break;
}
else
{
yield return null;
}
}
}
attemptNumber++;
}
if (results.Count != 0)
{
ProcessResponseFail("Timed out");
}
else
{
ProcessResponseFail("Unable to generate a request");
}
}
Where TIMEOUT is a TimeSpan of 10 seconds. And IsAnyResultCompleted is just a for loop that checks if any request has IsCompleted set to true.
Here I create and send the request:
IAsyncResult SendRequest()
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(RequestActionPath);
request.ContentType = "application/json";
request.Accept = "application/json";
request.Method = "POST";
string json = JsonUtility.ToJson(_dependency);
using (StreamWriter sw = new StreamWriter(request.GetRequestStream()))
{
sw.Write(json);
sw.Flush();
}
IAsyncResult result = request.BeginGetResponse(new AsyncCallback(onResponse), request);
return result;
}
"onResponse" is a cached delegate and it is assigned to this:
void OnResponse(IAsyncResult asynchronousResult)
{
try
{
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
request.EndGetResponse(asynchronousResult);
}
catch (WebException e)
{
string responseStream;
using (var streamReader = new StreamReader(e.Response.GetResponseStream()))
{
responseStream = streamReader.ReadToEnd();
}
Utility.Console.LogError(responseStream);
}
}
I am well aware of this and I also tried to set ServicePointManager.DefaultConnectionLimit = 1000000 but the result is always the same, after 2 sent requests GetRequestStream() in SendRequest stalls for 5 seconds and I cannot understand why.

HttpWebRequest.GetRequestStream() Timeout

I have a service that builds an HttpWebRequest and sets its body with a JSON string to be sent to a system's API. At the point of calling for the request stream, I am ocassionaly getting a WebException timeout error. Why would it error at this point? Does it test connecting to the other system before continuing?
try
{
//Get default request data
if (requestObj == null)
requestObj = new ApiRequest();
//Convert request info to json+bytes
string url = _baseUrl + path;
string requestStr = JsonConvert.SerializeObject(requestObj, _jsonSettings);
requestObjJson = requestStr;
byte[] data = Encoding.UTF8.GetBytes(requestStr);
//Post to SystemX
webRequest = (HttpWebRequest)WebRequest.Create(url);
webRequest.ContentType = "application/json;charset=UTF-8";
webRequest.Headers.Add("access_token", _accessToken);
webRequest.Method = "POST";
webRequest.ContentLength = data.Length;
webRequestJson = JsonConvert.SerializeObject(webRequest, Formatting.Indented);
using (Stream dataStream = webRequest.GetRequestStream())
{
dataStream.Write(data, 0, data.Length);
dataStream.Close();
}
webRequestJson = JsonConvert.SerializeObject(webRequest, Formatting.Indented);
LogMessage("SystemXApiAdapter._request() Request", "Information only. Not an error.", webRequestJson + ";" + requestObjJson, connectionString, customerName, licenseInfoID);
//Get response
string responseString = null;
HttpStatusCode status;
using (HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse())
{
if (response != null)
{
using (Stream stream = response.GetResponseStream())
using (StreamReader sr = new StreamReader(stream))
{
responseString = sr.ReadToEnd();
status = response.StatusCode;
}
response.Close();
}
else
{
status = HttpStatusCode.NoContent;
}
}
T responseObj = null;
LogMessage("SystemXApiAdapter._request() Response", "Information only. Not an error.", responseString, connectionString, customerName, licenseInfoID);
if (typeof(T) == typeof(EmptyApiResponse))
return null;
if (string.IsNullOrEmpty(responseString))
throw new Exception("Empty response for non-empty request");
responseObj = JsonConvert.DeserializeObject<T>(responseString);
if (callback != null)
callback(responseObj);
//Get next page of data if needed
if (handlePaging && status == HttpStatusCode.PartialContent)
{
//Move to next page and recursively make more requests until we've got everything
requestObj.page_num++;
T moreData = _request<T>(path, connectionString, customerName, licenseInfoID, true, requestObj, callback);
if (moreData != null)
responseObj = (T)(responseObj).AppendResponseData(moreData);
}
return responseObj;
}
catch (Exception ex)
{
SystemXApiException SystemXEx = new SystemXApiException(requestObj, ex, webRequestJson);
if (!bIsRetry && SystemXEx.StatusCode.HasValue && retryOnStatuses.Contains(SystemXEx.StatusCode.Value))
{
return _request<T>(path, connectionString, customerName, licenseInfoID, handlePaging, requestObj, callback, true);
}
else
{
throw SystemXEx;
}
if (ex is WebException)
{
WebException webEx = (WebException)ex;
HttpStatusCode? StatusCode = null;
string responseBody = null;
//Read Status Code
if (webEx.Status == WebExceptionStatus.ProtocolError)
{
var response = webEx.Response as HttpWebResponse;
if (response != null)
{
StatusCode = response.StatusCode;
}
}
//Retry once on applicable status code
if (!bIsRetry && StatusCode.HasValue && retryOnStatuses.Contains(StatusCode.Value))
return _request<T>(path, connectionString, customerName, licenseInfoID, handlePaging, requestObj, callback, true);
//Read response Body
if (webEx.Response != null)
{
using (Stream responseStream = webEx.Response.GetResponseStream())
using (StreamReader sr = new StreamReader(responseStream, Encoding.Default))
{
responseBody = sr.ReadToEnd();
}
}
else
{
responseBody = "Empty response body.";
}
string message = null;
//Format new Exception
if (StatusCode.HasValue)
message = string.Format("{0} {1}: {2}: {3}: {4}", (int)StatusCode, StatusCode.ToString(), responseBody, requestObjJson, webRequestJson);
else
message = string.Format("{0} {1}: {2}: {3}: {4}", "No status code", "No status code", responseBody, requestObjJson, webRequestJson);
throw new Exception(message, ex);
}
else
throw;
}
finally
{
if (webRequest != null)
{
webRequest.Abort();
}
}

One option is to increase the time limit.
https://msdn.microsoft.com/pt-br/library/system.net.httpwebrequest.timeout(v=vs.110).aspx
webRequest.Timeout=2000; (2 seconds)
Another is to repeat the execution after a timeout, waiting x seconds.
Any connection can go through problems, your code need to be prepared for this.
I hope it helped in someway.

How do I reissue a webrequest? Must I recreate Webclient?

The following code gets stuck in a while loop when an exception is encountered. This is because GetResponse is caching the data.
According to fiddler, no data after the first request is issued.
Is it a best practice to recreate the webclient to solve the "refresh" issue I'm having?
private static ReportStatusEnum GetReportStatus(string domain, string oAuthKey, long permissionReportID)
{
string target = string.Format("https://{0}.egnyte.com/pubapi/v1/audit/jobs/{1}", domain, permissionReportID);
var client = new WebClient();
string result ="";
var request = (HttpWebRequest)WebRequest.Create(target);
request.ContentType = "application/json";
request.Headers.Add("Authorization", "Bearer " + oAuthKey);
request.AllowAutoRedirect = false;
bool callComplete = false;
while (callComplete != true)
{
try
{
using (var response = request.GetResponse())
{
using (StreamReader reader = new StreamReader(response.GetResponseStream()))
{
result = reader.ReadToEnd();
}
}
JToken result2 = JObject.Parse(result);
var statusResult = result2.SelectToken("status");
ReportStatusEnum ret = ReportStatusEnum.error;
Enum.TryParse<ReportStatusEnum>(statusResult.ToString(), out ret);
Console.WriteLine("The returned variable is:" + ret);
callComplete = true;
return ret;
}
catch (System.Net.WebException e)
{
if (e.Response != null)
if (e.Response.ContentLength > 0)
{
if (e.Response.Headers["X-Mashery-Error-Code"] == "ERR_403_DEVELOPER_OVER_QPS")
{
Thread.Sleep(60000); Console.Write("*QPS HIT*");
}
}
}
}
return ReportStatusEnum.error;
}

No. HttpWebRequests are not reusable.
Just move the creation of your WebRequest into the body of your loop:
string result ="";
bool callComplete = false;
while (callComplete != true)
{
var request = (HttpWebRequest)WebRequest.Create(target);
request.ContentType = "application/json";
request.Headers.Add("Authorization", "Bearer " + oAuthKey);
request.AllowAutoRedirect = false;
//...

can I check if a file exists at a URL?

I know I can locally, on my filesystem, check if a file exists:
if(File.Exists(path))
Can I check at a particular remote URL?

If you're attempting to verify the existence of a web resource, I would recommend using the HttpWebRequest class. This will allow you to send a HEAD request to the URL in question. Only the response headers will be returned, even if the resource exists.
var url = "http://www.domain.com/image.png";
HttpWebResponse response = null;
var request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "HEAD";
try
{
response = (HttpWebResponse)request.GetResponse();
}
catch (WebException ex)
{
/* A WebException will be thrown if the status of the response is not `200 OK` */
}
finally
{
// Don't forget to close your response.
if (response != null)
{
response.Close();
}
}
Of course, if you want to download the resource if it exists it would most likely be more efficient to send a GET request instead (by not setting the Method property to "HEAD", or by using the WebClient class).

If you want to just copy & paste Justin's code and get a method to use, here's how I've implemented it:
using System.Net;
public class MyClass {
static public bool URLExists (string url) {
bool result = false;
WebRequest webRequest = WebRequest.Create(url);
webRequest.Timeout = 1200; // miliseconds
webRequest.Method = "HEAD";
HttpWebResponse response = null;
try {
response = (HttpWebResponse)webRequest.GetResponse();
result = true;
} catch (WebException webException) {
Debug.Log(url +" doesn't exist: "+ webException.Message);
} finally {
if (response != null) {
response.Close();
}
}
return result;
}
}
I'll keep his observation:
If you want to download the resource, and it exists, it would be more efficient to send a GET request instead by not setting the Method property to "HEAD" or by using the WebClient class.

Below is a simplified version of the code:
public bool URLExists(string url)
{
bool result = true;
WebRequest webRequest = WebRequest.Create(url);
webRequest.Timeout = 1200; // miliseconds
webRequest.Method = "HEAD";
try
{
webRequest.GetResponse();
}
catch
{
result = false;
}
return result;
}

If you are using a unc path or a mapped drive, this will work fine.
If you are using a web address (http, ftp etc) you are better off using WebClient - you will get a WebException if it doesn't exist.

public static bool UrlExists(string file)
{
bool exists = false;
HttpWebResponse response = null;
var request = (HttpWebRequest)WebRequest.Create(file);
request.Method = "HEAD";
request.Timeout = 5000; // milliseconds
request.AllowAutoRedirect = false;
try
{
response = (HttpWebResponse)request.GetResponse();
exists = response.StatusCode == HttpStatusCode.OK;
}
catch
{
exists = false;
}
finally
{
// close your response.
if (response != null)
response.Close();
}
return exists;
}

I had the same problem to solve in asp.net core, I've solved with HttpClient
private async Task<bool> isFileExist(string url)
{
using (HttpClient client = new HttpClient())
{
var restponse = await client.GetAsync(url);
return restponse.StatusCode == System.Net.HttpStatusCode.OK;
}
}

My version:
public bool IsUrlExist(string url, int timeOutMs = 1000)
{
WebRequest webRequest = WebRequest.Create(url);
webRequest.Method = "HEAD";
webRequest.Timeout = timeOutMs;
try
{
var response = webRequest.GetResponse();
/* response is `200 OK` */
response.Close();
}
catch
{
/* Any other response */
return false;
}
return true;
}

WebRequest will waiting long time(ignore the timeout user set) because not set proxy, so I change to use RestSharp to do this.
var client = new RestClient(url);
var request = new RestRequest(Method.HEAD);
request.Timeout = 5000;
var response = client.Execute(request);
result = response.StatusCode == HttpStatusCode.OK;

Thanks for all answers.
And I would like to add my implementation which includes default state when we get errors, for specific cases like mine.
private bool HTTP_URLExists(String vstrURL, bool vResErrorDefault = false, int vTimeOut = 1200)
{
bool vResult = false;
WebRequest webRequest = WebRequest.Create(vstrURL);
webRequest.Timeout = vTimeOut; // miliseconds
webRequest.Method = "HEAD";
HttpWebResponse response = null;
try
{
response = (HttpWebResponse)webRequest.GetResponse();
if (response.StatusCode == HttpStatusCode.OK) vResult = true;
else if (response.StatusCode == HttpStatusCode.NotFound) vResult = false;
else vResult = vResErrorDefault;
}
catch (WebException ex)
{
if (ex.Status == WebExceptionStatus.ProtocolError && ex.Response != null)
{
var resp01 = (HttpWebResponse)ex.Response;
if (resp01.StatusCode == HttpStatusCode.NotFound)
{
vResult = false;
}
else
{
vResult = vResErrorDefault;
}
}
else
{
vResult = vResErrorDefault;
}
}
finally
{
// Don't forget to close your response.
if (response != null)
{
response.Close();
}
}
return vResult;
}

Anoter version with define timeout :
public bool URLExists(string url,int timeout = 5000)
{
...
webRequest.Timeout = timeout; // miliseconds
...
}

This works for me:
bool HaveFile(string url)
{
try
{
using (WebClient webClient = new WebClient())
{
webClient.DownloadString(url);
}
return true;
}
catch (Exception)
{
return false;
}
}