Avoid exception while using Web APIs

Question

User1447694405 posted

Hi All,
My task is take users from one API and Put in someother API. before puting into new API i need to check this user is existing or not. But while i checking if its not exsting getting exception like 404. How can i avoid this. if not there i need to add this data as new user

var http = (HttpWebRequest)WebRequest.Create(new Uri("https://actjira.atlassian.net/rest/api/2/user?username="+ username));
 http.ContentType = "application/json";
 http.Method = "GET";
 http.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes(String.Format("{0}:{1}", "username", "password"))));

HttpWebResponse response = http.GetResponse() as HttpWebResponse;  // from here i getting exception

Answer 1

User541108374 posted

Hi,

what is the exception you're seeing? Can you call the REST API from a tool like Fiddler or Postman? If so, compare to what you're sending with those tools. Perhaps you're missing something or put in something too much.

Grz, Kris.

Answer 2

User1447694405 posted

Thanks for your reply

Below i pasting exception i getting

An exception of type 'System.Net.WebException' occurred in System.dll but was not handled in user code

Additional information: The remote server returned an error: (404) Not Found.

When i copy paste same url  in browser i getting correct error message like user not existing

Answer 3

User541108374 posted

Hi,

An exception of type 'System.Net.WebException' occurred in System.dll but was not handled in user code

Put a try catch statement around your code and in the exception you could get more information from it if that's what you're after.

The 404 seems a bit puzzling as it states that it doesn't find the endpoint. Can you check the url you're using and the url in the browser are exactly the same? Debug your code and copy paste the generated url into your browser to see it.

Grz, Kris.

Answer 4

User-782957977 posted

Looks like rest service (https://actjira.atlassian.net/rest/api/2/user) is returning HttpStatusCode.NotFound when user is not found. HttpWebRequest will throw exception if response has NotFound status code. You need to use either try catch with WebRequest or use HttpClient

WebRequest

 try
             {
                 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
             }
             catch (System.Net.WebException ex)
             {
                 var response = ex.Response as HttpWebResponse;
                 if (response!= null && response.StatusCode == HttpStatusCode.NotFound)
                 {

                 }
             }

HttpClient

using (var client = new HttpClient())
             {
                 client.DefaultRequestHeaders.Accept.Clear();
                 client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                 var response = client.GetAsync("url").Result;
                 if (response.IsSuccessStatusCode)
                 {
                     string responseString = response.Content.ReadAsStringAsync().Result;
                     
                 }
                 else if (response.StatusCode == HttpStatusCode.NotFound)
                 {

                 }

             }

Answer 5

User-2057865890 posted

Hi binumon03,

You could try to change the response type. The following code is for your reference.

using (var client = new HttpClient(new HttpClientHandler { AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate }))
{
   client.BaseAddress = new Uri("https://localhost:44300/");
   //client.DefaultRequestHeaders.Accept.Clear();
   client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
   client.DefaultRequestHeaders.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes(String.Format("{0}:{1}", "Admin", "123"))));
   HttpResponseMessage response = client.GetAsync("api/values?name=1").Result;
   //response.EnsureSuccessStatusCode();
   string result = response.Content.ReadAsStringAsync().Result;
   Console.WriteLine("Result: " + result);
}

Best Regards,

Chris Zhao