I'm quite new to c# and I'm having an issue when trying to call an API to post some CSV data using the following code:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://myurl");
request.Method = "POST";
request.Headers.Add("X-Api-Key:" + apiKey);
request.Headers.Add("X-Api-Secret:" + apiSecret);
request.ContentType = "text/csv";
using (StreamWriter swCSVData = new StreamWriter(request.GetRequestStream()))
{
StreamReader csvReader = new StreamReader(File.OpenRead("C:\\Test\\conf-ato-sprmbrinfo-batch-001.csv"));
while (!csvReader.EndOfStream)
{
swCSVData.WriteLine(csvReader.ReadLine());
}
csvReader.Close();
}
HttpWebResponse response = null;
try
{
Console.WriteLine("Attempting response....");
response = (HttpWebResponse)request.GetResponse();
Console.WriteLine("Got response....");
using (Stream responseStream = response.GetResponseStream())
{
if (responseStream != null)
{
using (StreamReader reader = new StreamReader(responseStream))
{
strResponseValue = reader.ReadToEnd();
}
}
}
Console.WriteLine(strResponseValue);
File.WriteAllText("C:\\Test\\apioutput.txt",strResponseValue);
}
catch ( Exception ex)
{
strResponseValue = "{\"errorMessages\":[\"" + ex.Message.ToString() + "\"],\"errors\":{}}";
}
If I run this code using the post test at ptsv2.com, then I can see that the api call looks like I would expect and I get a response. However, when I change my code to point to my required URL it seems to just hang on the following line:
response = (HttpWebResponse)request.GetResponse();
Does anyone have any idea as to why this could be happening?
Also happy for any recommendations to make my code better.
Thanks in advance.
It turns out this was a security issue once I could see the exception being returned. I had to add the following line of code for my request:
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
Thanks to the people who took the time to comment on my original question.
Related
I am using Postman to get the response from rest end point, and if I pass wrong data I am getting 400 exception which is very correct as per the logic.
But if I try to call the same web request from C# code(with same wrong parameter), I am getting exception but not the same as I am getting in Postman tool.
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://apiurl");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Headers.Add("Authorization", "Bearer " + token);
httpWebRequest.Method = "POST";
httpWebRequest.UserAgent = ".Net application";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = JsonConvert.SerializeObject(obj);//obj is parameter
streamWriter.Write(json);
}
try
{
HttpWebResponse httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
}
}
catch (WebException e)
{
}
Can I know why I am getting errors differently from postman and C# code
Regards
Anand
Added below code in the exception block and it gave me the same response as Postman
catch(WebException ex)
{
string message = ex.Message;
WebResponse errorResponse = ex.Response;
if (errorResponse != null)
{
using (Stream responseStream = errorResponse.GetResponseStream())
{
StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
message = reader.ReadToEnd();
}
}
}
I've got a web service that returns an http 500 with some diagnostic information in the body of the response.
I'm doing something like
Stream responseStream = null;
WebResponse _Response = null;
Stream responseStream = null;
HttpWebRequest _Request = null;
try
{
_Response = _Request.GetResponse();
responseStream = _Response.GetResponseStream();
}
catch {
//try to view the Request.GetResponse() body here.
}
Since _Request.GetResponse() is returning an http 500 there doesn't seem to be a way to view the response body. According to HTTP 500 Response with Body? this was a known issue in Java 9 years ago. I'm wondering if there's a way to do it in .NET today.
The microsoft docs give a good run down of what HttpWebRequest.GetResponse returns if it fails, you can check it out here https://learn.microsoft.com/en-us/dotnet/api/system.net.httpwebrequest.getresponse?view=netframework-4.8
In your example I believe you need to check for WebException and handle it.
Stream responseStream = null;
WebResponse _Response = null;
Stream responseStream = null;
HttpWebRequest _Request = null;
try
{
_Response = _Request.GetResponse();
responseStream = _Response.GetResponseStream();
}
catch (WebException w)
{
//here you can check the reason for the web exception
WebResponse res = w.Response;
using (Stream s = res.GetResponseStream())
{
StreamReader r= new StreamReader(s);
string exceptionMessage = r.ReadToEnd(); //here is your error info
}
}
catch {
//any other exception
}
So I'm following the WingTip Toy tutorial, and I know its sort of old but it was error free until I got to the point where I needed to checkout with PayPal using the sandbox developing tool
This is the code where the error occurs
//Retrieve the Response returned from the NVP API call to PayPal.
HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
string result;
using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
{
result = sr.ReadToEnd();
}
return result;
And this is the error im getting when i run it
[ProtocolViolationException: You must write ContentLength bytes to the request stream before calling [Begin]GetResponse.]
Please note I'm a beginner
Edit: The full code is here
public string HttpCall(string NvpRequest)
{
string url = pEndPointURL;
string strPost = NvpRequest + "&" + buildCredentialsNVPString();
strPost = strPost + "&BUTTONSOURCE=" + HttpUtility.UrlEncode(BNCode);
HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create(url);
objRequest.Timeout = Timeout;
objRequest.Method = "POST";
objRequest.ContentLength = strPost.Length;
try
{
using (StreamWriter myWriter = new StreamWriter(objRequest.GetRequestStream()))
{
myWriter.Write(strPost);
}
}
catch (Exception)
{
// No logging for this tutorial.
}
//Retrieve the Response returned from the NVP API call to PayPal.
HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse();
string result;
using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
{
result = sr.ReadToEnd();
}
return result;
}
objRequest.ContentLength = strPost.Length;
What are you trying to do here? The framework sets the content length automatically. The content length is in bytes but you have given the number of characters.
That's why the error complains: You have written a different number of characters than you said you would write.
Delete that line.
Your code would become a lot simpler if you used HttpClient. Should be about 5 lines.
I'm trying to call http://genderize.io/ , but i'm getting an error from .NET saying:
{"You must provide a request body if you set ContentLength>0 or SendChunked==true. Do this by calling [Begin]GetRequestStream before [Begin]GetResponse."}
How would I call this web service "http://api.genderize.io/?name=peter" from C# and get a JSON string back?
HttpWebRequest request;
string postData = "name=peter"
URL = "http://api.genderize.io/?"
Uri uri = new Uri(URL + postData);
request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = postData.Length;
request.AllowAutoRedirect = true;
UTF8Encoding enc = new UTF8Encoding();
string result = string.Empty;
HttpWebResponse Response;
try
{
using (Response = (HttpWebResponse)request.GetResponse())
{
using (Stream responseStream = Response.GetResponseStream())
{
using (StreamReader readStream = new StreamReader(responseStream, Encoding.UTF8))
{
return readStream.ReadToEnd();
}
}
}
}
catch (Exception ex)
{
Debug.WriteLine("Error: " + ex.Message);
throw ex;
}
You are making the call to the service using POST method, reading through the comments area in http://genderize.io/ the author states that only GET method requests are allowed.
Stroemgren: Yes, this is confirmed. Only HTTP GET request are allowed.
This answer probably would be better as a comment, but I don't have enough reputation :(
When I run this code to call the Google API, all I get is a 'Bad Request' error, but I don't know where I'm going wrong.
The code is being returned no problem from the authorization page on Google, it's when the code gets to the part below that it fails. Please could someone tell me where I'm going wrong here?
I'm aware that there are libraries for this, but I'm trying to understand how to do this the RESTful way as a learning exercise.
Thanks
var code = Request.QueryString["code"];
var accessToken = string.Empty;
var req0 = WebRequest.Create("https://accounts.google.com/o/oauth2/token");
req0.Method = "POST";
string postData = string.Format("code={0}&client_id={1}&client_secret={2}&redirect_uri= {3}&grant_type=authorization_code",
code, //the code i got back
"xxxx.apps.googleusercontent.com",
"xxx",
Url.Encode("http://localhost/home/callback")
); //my return URI
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
req0.ContentType = "application/x-www-form-urlencoded";
req0.ContentLength = byteArray.Length;
using (Stream dataStream = req0.GetRequestStream())
{
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
}
try
{
using (WebResponse response = req0.GetResponse())
{
using (var dataStream = response.GetResponseStream())
{
using (StreamReader reader = new StreamReader(dataStream))
{
string responseFromServer = reader.ReadToEnd();
var ser = new JavaScriptSerializer();
accessToken = ser.DeserializeObject(responseFromServer).ToString();
}
}
}
}
catch (WebException wex)
{
Debug.WriteLine(wex.ToString());
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString());
}
The Google API is very finicky when it comes to what you have entered into the API Console for your client id return URI, and what you enter in your code to call it.
I was missing the trailing forward slash. That was all. Lesson learnt...
Thanks to Jon and Sandeep for help point me in the right direction by comparing what was in the network traffic, and what I should have been sending.