how to check web api is down or not in c# code

Ashok

6y6.4kLearn iOS Programming

Hi,

Thanks in advance :)

readonly string Baseurl = "http://localhost:123456/";
public string GetUserID_By_UserName(string Username)
{
string UserName = "";
using (HttpClient client = new HttpClient())
{
client.BaseAddress = new Uri(Baseurl);
client.DefaultRequestHeaders.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
try
{
var response = client.GetAsync("api/Values/UserID_By_UserName?username=" + Username).Result;
// Here how i can check the api is working or not how to get the status to display of the api.
}
}
}

10 Replies

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Salman Beg6y ago
When you call getAsync method then definitely you will get some response code. Check my first reply there I explained you about status code and based on that you can give some message. Thanks.
Ashok6y ago
If that api does'nt run(let's say for somereson its stopped if so can'nt we get any response or something..) how can we check wheather API is down or not how can we show a message or log the exception that API is down/not

Thanks :)
Salman Beg6y ago
The error is saying that it is unable to connect with the API. This is a problem with the API side. Check with the person who is the administrator of that API. Thanks
Ashok6y ago
Hi,

getting this error :)

{System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: Unable to connect to the remote server --->
System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 123.0.0.1:57787
at System.Net.Sockets.Socket.InternalEndConnect(IAsyncResult asyncResult)
at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult)
at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar)
--- End of inner exception stack trace ---}
Salman Beg6y ago
Hey. Directly you are hitting to catch block means you are getting some error. Thanks.
Ashok6y ago
Hi Salman,

Thanks for the reply I tried your code could'nt get any status its directly going to the catch block of a method where i am calling the below code in that method.
readonly string Baseurl = "http://localhost:123456/";
public string GetUserID_By_UserName(string Username)
{
string UserName = "";
using (HttpClient client = new HttpClient())
{
client.BaseAddress = new Uri(Baseurl);
client.DefaultRequestHeaders.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
try
{
var response = client.GetAsync("api/Values/UserID_By_UserName?username=" + Username).Result;
// Here how i can check the api is working or not how to get the status to display of the api.
}
}
}
Salman Beg6y ago
Hi.
When you get a response then at that same time it will return a status code also. So if you just check that status code then you can easily know whether the url is working or not.
Here is a sample code,
if (response.StatusCode == HttpStatusCode.OK || response.StatusCode == HttpStatusCode.Created || response.StatusCode.Accepted)
    {
        //Available
    }
    else
    {
       //Not Available
    }
To know more about all the status code then follow this link,
https://restfulapi.net/http-status-codes/

Thanks.
Ashutosh Gupta6y ago
try
{
var response = client.GetAsync("api/Values/UserID_By_UserName?username=" + Username);
}
catch(HttpRequestException ex)
{
// log excpetion
}
Ashok6y ago
Hi Ashutosh Gupta,

Thanks for the reply can i have the sample code.
Ashutosh Gupta6y ago
httlpclient.getasync can throw three type of excpetion which you can handle in your code
ArgumentNullException, HttpRequestException, TaskCanceledException
you get HttpRequestException whenweb api is down or network connectivity, DNS failure, server certificate validation or timeout. i hope you have defned the timeout for your web api.

i hope you get the answer to your query.