I am attempting to create a console app that sends a WebRequest to a website so that I can get some information back from it in JSON format. Once I build up the request and try to get response I just want to simply print out the data, but when I call httpWebRequest.getResponse() it returns NULL.
I have tried multiple other methods of sending the data to the the url but those are all giving me like 404, or 400 errors, etc. This method at least isn't giving me any error, just a NULL.
Here is a snapshot of the documentation I am using for the API (albeit the docs aren't complete yet):
Here is the console app code that I have right now:
try
{
var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://api.remot3.it/apv/v27/user/login");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "POST";
httpWebRequest.Headers.Add("developerkey", "***KEY***");
using (var streamWriter = new
StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = new JavaScriptSerializer().Serialize(new
{
email = "***EMAIL***",
password = "***PASSWORD***"
});
Console.WriteLine(json);
streamWriter.Write(json);
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
Console.WriteLine(result);
Console.ReadLine();
}
}catch(Exception e)
{
Console.WriteLine(e.Message);
Console.WriteLine(e.StackTrace);
Console.ReadLine();
}
Expected output is some JSON data, but I am getting a NULL back from getResponse().
Try to serialize the credential in your form and for header send as parameter for this class.
Check below for my code. It is not 100 % fit to your requirement, but atleast it will help to get through your logic.
Here is what I get Json Response from this code. Its work Perfect. Please remember to add timeout option on your webrequest and at the end close the streamreader and stream after completing your task. please check this code.
public static string httpPost(string url, string json)
{
string content = "";
byte[] bs;
if (json != null && json != string.Empty)
{
bs = Encoding.UTF8.GetBytes(json);
}
else
{
bs = Encoding.UTF8.GetBytes(url);
}
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
req.Method = "POST";
if (json != string.Empty)
req.ContentType = "application/json";
else
req.ContentType = "application/x-www-form-urlencoded";
req.KeepAlive = false;
req.Timeout = 30000;
req.ReadWriteTimeout = 30000;
//req.UserAgent = "test.net";
req.Accept = "application/json";
req.ContentLength = bs.Length;
using (Stream reqStream = req.GetRequestStream())
{
reqStream.Write(bs, 0, bs.Length);
reqStream.Flush();
reqStream.Close();
}
using (WebResponse wr = req.GetResponse())
{
Stream s = wr.GetResponseStream();
StreamReader reader = new StreamReader(s, Encoding.UTF8);
content = reader.ReadToEnd();
wr.Close();
s.Close();
reader.Close();
}
return content;
}
Related
Am doing an WEB API .net 4.62 that /Token with username password and grant_type to get access token once its generated i woul like to get it value of access_token.This does not happen but when i take the same code to a windows form aplication I am able to get it what could be wrong. It hangs on using (HttpWebResponse response = (HttpWebResponse)http.GetResponse())
try
{
string myParameters = "username=value1&password=value2&grant_type=password";
string baseAddress = "http://localhost:50128/token";
var http = (HttpWebRequest)WebRequest.Create(new Uri(baseAddress));
http.Accept = "application/x-www-form-urlencoded";
http.ContentType = "application/x-www-form-urlencoded";
http.Method = "POST";
string parsedContent = myParameters;
ASCIIEncoding encoding = new ASCIIEncoding();
Byte[] bytes = encoding.GetBytes(parsedContent);
Stream newStream = http.GetRequestStream();
newStream.Write(bytes, 0, bytes.Length);
newStream.Close();
http.ServicePoint.Expect100Continue = false;
http.ProtocolVersion = HttpVersion.Version11;
http.Timeout = 2000;
using (HttpWebResponse response = (HttpWebResponse)http.GetResponse())
{
var stream = response.GetResponseStream();
var sr = new StreamReader(stream);
var content = sr.ReadToEnd();
JObject json = JObject.Parse(content);
var message = json.SelectToken("access_token").ToString();
Console.Write(message);
}
}
catch (Exception ex)
{
//Handle the exceptions that could appear
}
change the using block like this and also convert your function to "async".
using (HttpWebResponse response = (HttpWebResponse)await Task.Factory.FromAsync(http.BeginGetResponse, http.EndGetResponse, null).ConfigureAwait(false))
let me know if it works.
How can I loop through the JSON results from this C# Rest API call:
string url = string.Format("https://example.com/api/mytext");
System.Net.HttpWebRequest req = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(url);
req.Method = "GET";
req.UserAgent = "mykey";
req.Accept = "text/json";
using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)req.GetResponse())
{
if (resp.StatusCode == System.Net.HttpStatusCode.OK)
{
// how do I access the JSON here and loop through it?
}
}
There is no "data" in the resp object:
Visual Studio doesn't seem to show any results in "resp" - but I know they are there, as I've seen results in postman.
Thanks, Mark
Use GetResponseStream() with a StreamReader
string url = string.Format("https://example.com/api/mytext");
System.Net.HttpWebRequest req = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(url);
req.Method = "GET";
req.UserAgent = "mykey";
req.Accept = "text/json";
using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)req.GetResponse())
{
if (resp.StatusCode == System.Net.HttpStatusCode.OK)
{
string contents;
// how do I access the JSON here and loop through it?
using(var responseStream = resp.GetResponseStream())
using(var responseStreamReader = new StreamReader(responseStream))
{
contents = responseStreamReader.ReadToEnd();
}
var deserializedContent = JsonConvert.DeserializeObject<T>(contents);
}
}
See more on GetResponseStream
See more on StreamReader
See more on JsonConvert
Dependencies: Newtonsoft.Json
Use HttpWebResponse.GetResponseStream method to get the result as a Stream. Then you can use Newtonsoft JSON.NET to parse the result.
using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)req.GetResponse())
{
if (resp.StatusCode == System.Net.HttpStatusCode.OK)
{
using (var stream = resp.GetResponseStream())
{
// Process data with JSON.NET library here
}
}
}
dynamic dynJson = JsonConvert.DeserializeObject(response);
I am doing an API Post request and cant seem to get it to work. I always get a sendFailure webexception and the response for the exception is always null so catching the exception is useless. It keeps happening when I try to get the httpWebResponse. I noticed too the request.contentlength gave errors at postream getrequeststream so i commented it out. Test.json is the file I use for the request body. I also tested this on different API testers by including the URL, body, and content-type in the header and they worked. I just cant seem to code it for myself. The credentials work I just dont know if im doing the request correctly?
JSON File:
{
"email": "abc#123.com",
"password": "12345",
"facilityNumber": "987654"
}
string filepath = "test.json";
string result = string.Empty;
using (StreamReader r = new StreamReader(filepath))
{
var json = r.ReadToEnd();
var jobj = JObject.Parse(json);
foreach (var item in jobj.Properties())
{
item.Value = item.Value.ToString().Replace("v1", "v2");
}
result = jobj.ToString();
Console.WriteLine(result);
}
try
{
string setupParameters;
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("https://www.test.com/abcde");
request.AllowAutoRedirect = true;
setupParameters = result;
ServicePointManager.ServerCertificateValidationCallback = (s, cert, chain, ssl) => true;
ASCIIEncoding encoding = new ASCIIEncoding();
var postData = setupParameters;
request.Method = "POST";
request.ContentType = "application/json";
byte[] data = encoding.GetBytes(postData);
//request.ContentLength = data.Length;
using (StreamWriter postStream = new StreamWriter(request.GetRequestStream()))//error if uncomment contentlength
{
postStream.Write(postData);
postStream.Flush();
postStream.Close();
}
HttpWebResponse wr = (HttpWebResponse)request.GetResponse();//error occurs
Stream receiveStream = wr.GetResponseStream();
StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);
}
catch (WebException ex)
{
if (ex.Response != null)
{
using (var errorResponse = (HttpWebResponse)ex.Response)
{
using (var reader = new StreamReader(errorResponse.GetResponseStream()))
{
string error = reader.ReadToEnd();
result = error;
}
}
}
I suggest modifiying your request to follow this format. Especially pay attention to the request.Method and request.ContentType which have caught me out multiple times.
Also, handling the response is easier this way.
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(YOURURL);
request.ContentType = "application/json; charset=utf8";
request.Headers.Add(ADD HEADER HERE IF YOU NEED ONE);
request.Method = WebRequestMethods.Http.Post; // IMPORTANT
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write(JsonConvert.SerializeObject(JSONBODYSTRING));
// I USUALLY YOU JSONCONVERT HERE TO SIMPLY SERIALIZE A STRING CONTAINING THE JSON INFO.
//BUT I GUESS YOUR METHOD WOULD ALSO WORK
streamWriter.Flush();
streamWriter.Close();
}
WebResponse response = request.GetResponse();
using (var streamReader = new StreamReader(response.GetResponseStream()))
{
string result = streamReader.ReadToEnd();
// DO WHATEVER YOU'D LIKE HERE
}
} catch (Exception ex)
{
// HANDLE YOUR EXCEPTIONS
}
I am trying to get cognos report using siteminder token, below is my code.
string cognosUrl = "https://cognos.blah.com";
string reportPath = "/c10/cgi-bin/cognosisapi.dll/rds/reportData/report/"; string reportId = "ildjfsldkf"; //prod
cognosUrl += string.Concat(reportPath, reportId,"?blahblah");
string targetUrl = cognosUrl;
string strFormvalues = string.Concat("TARGET=",targetUrl);
ASCIIEncoding encoder = new ASCIIEncoding();
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(targetUrl);
byte[] data = encoder.GetBytes(strFormvalues);
request.AllowAutoRedirect = false;
request.Timeout = 120000;
request.ContentLength = data.Length;
request.ContentType = "text/xml;charset=\"utf-8\"";
request.Method = "POST";
request.Headers.Add(HttpRequestHeader.Cookie,"SMSESSION="+stoken);
request.GetRequestStream().Write(data, 0, data.Length);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);
string json = reader.ReadToEnd();
byte[] byteArray = Encoding.UTF8.GetBytes(json);
MemoryStream restream = new MemoryStream(byteArray);
using (Stream output = File.OpenWrite(#"c:\\Projects\\Test_"+DateTime.Now.ToString("yyyyMMddHHmmssfff")+".txt"))
using (Stream input = restream)
{
if (input != null) input.CopyTo(output);
}
// var results = serializer.DeserializeObject(json);
reader.Close();
dataStream.Close();
response.Close();
But I am getting response as " DPR-ERR-2101 Your request was invalid.Please contact your administrator."
I am not using C# myself, but a few recommendations while debugging this:
If you are only posting a URL, why not use GET instead of POST?
Try paste the targetURL in your browser, see what happens.
In my setup, when I paste the URL in the browser, I am always redirected before I receive an answer. (to a URL like, /cgi-bin/cognosisapi.dll/rds/sessionOutput/conversationID/i292ED29A62474697AD44306A388F5BBB You are preventing that to happen, that might be an issue)
Hope that helps.
I am using HttpWebRequest to get webpage source code with POST method.
The page needs to be accessed for multiple times with different parameters.
When getting response in the second time in a short period, it always return the same response object to me. After debugging, if the second call is after around 30 seconds, the request can get the correct response object(source code).
public HtmlAgilityPack.HtmlDocument getHtmlData(string url, string cname)
{
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
try
{
HttpRequestCachePolicy policy = new HttpRequestCachePolicy(HttpRequestCacheLevel.Default);
HttpWebRequest.DefaultCachePolicy = policy;
HttpRequestCachePolicy noCachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.NoCacheNoStore);
HttpWebRequest req = WebRequest.Create(url) as HttpWebRequest;
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.KeepAlive = false;
req.Headers[HttpRequestHeader.CacheControl] = "no-cache";
req.Headers[HttpRequestHeader.Pragma] = "no-cache";
req.IfModifiedSince = DateTime.Now;
req.CachePolicy = noCachePolicy;
//add post data
string postData = "cname=" + cname;
byte[] byteArray = Encoding.GetEncoding("shift-jis").GetBytes(postData);
req.ContentLength = byteArray.Length;
using (Stream stream = req.GetRequestStream())
{
stream.Write(byteArray, 0, byteArray.Length);
}
// get response
string data = "";
HttpWebResponse response = req.GetResponse() as HttpWebResponse;
using (var stream = response.GetResponseStream())
{
StreamReader reader = new StreamReader(stream, Encoding.GetEncoding("shift-jis"));
data = reader.ReadToEnd();
reader.Close();
}
response.Close();
doc.LoadHtml(data);
//System.Threading.Thread.Sleep(30000);
}
catch(Exception ex)
{
Log.log.Debug(ex.ToString());
}
return doc;
}
Function call block:
getHtmlData(#"http://www.jra.go.jp/JRADB/accessS.html", "pw01sli00/AF");
getHtmlData(#"http://www.jra.go.jp/JRADB/accessS.html", "pw01skl00999999/B3");
getHtmlData(#"http://www.jra.go.jp/JRADB/accessS.html", "pw01skl00201604/E3");
I have stuck with the problem for a whole day. hope someone can give me a clue.
Many thanks!