How to use IHttpClientFactory or HttpClient to call multiple API's?

Sujeet Raman

5y1.1k.NET

Hi all,

I am new to ASP.net core web API.I was trying to create a main API which will call 2 services (concider these 2 are micro services)

1.api/school/getdetails

2.api/college/details

i gone through some article and i understood IHttpClientFactory or HttpClient can help to this but i am not sure how to use these.Lots of articles confusing me..

main api should be......... http://SYS09X.com:5008/api/school/getdetails

MainAPI........calls.........school service,college service

please help me with some article or suggestion for my understanding

5 Replies

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Rijwan Ansari5y ago
Better use API gateway if those services are microservices. API gateway gives server flexibility to handle multiple api services.
Here are some link to implement api gateway.
https://www.c-sharpcorner.com/article/microservices-with-ocelot-apigateway-in-asp-net-core/
https://docs.microsoft.com/en-us/dotnet/architecture/microservices/multi-container-microservice-net-applications/implement-api-gateways-with-ocelot

For understanding api gateway in more details:
https://docs.microsoft.com/en-us/dotnet/architecture/microservices/architect-microservice-container-applications/direct-client-to-microservice-communication-versus-the-api-gateway-pattern

Let us know your feedback.

Regards
Rijwan
+4
Sujeet Raman5y ago
BaseUrl = ConfigurationManager.AppSettings["url"];// ex //http:localhost:3456/api/Employee

here we have to give the main api url only right?
example- url=http:localhost:3456 only

bith customer and employee mrthodes i can call seperately right
+3
Sachin Singh5y ago
@swayam yes for httpClient nothing will change in .net core
call //http:localhost:3456/api/Employee as
HttpClient client =new HttpClient();
HttpResponseMessage getEmployee = client.GetAsync("http://1234/api/Employee").Result;
if (getEmployee.IsSuccessStatusCode)
{
    emps = getEmployee.Content.ReadAsAsync>().Result.ToList();
    return Json(emps,JsonRequestBehavior.AllowGet) ;
}
and //http:localhost:3456/api/Customer as
HttpClient client =new HttpClient();
HttpResponseMessage getCustomers = client.GetAsync("http://1234/api/Customer").Result;
if (getCustomers .IsSuccessStatusCode)
{
    custs= getCustomers.Content.ReadAsAsync>().Result.ToList();
    return Json(custs,JsonRequestBehavior.AllowGet) ;
}
+4
Sujeet Raman5y ago
Hi sachin i have few doubts here as a biginer

1.This is in MVC right i am using asp.net core api so no view part will be there so i can use same in api also?

2. in http:localhost:3456/api/Employee ,http:localhost:3456 is common right?

3.If i want use api/Employee and api/Customer responses seperately what should I do?

4.How can I combain these 2 responses in a main API?

5.How we add 2 url here?

BaseUrl = ConfigurationManager.AppSettings["url"];// ex //http:localhost:3456/api/Employee and //http:localhost:3456/api/Customer

Thanks
+3
Sachin Singh5y ago
This is how we use http client
public class EmployeeController : Controller
      {
        //
        // GET: /Employee/

        private readonly HttpClient client;
        private readonly string BaseUrl;

        public EmployeeController()
        {
            client = new HttpClient();
            BaseUrl = ConfigurationManager.AppSettings["url"];// ex //http:localhost:3456/api/Employee
            client.BaseAddress = new Uri(BaseUrl);
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        }
        public ActionResult Index()
        {

            return View();
        }

     }

       public ActionResult GetAllEmployee()
        {
            List emps = new List();
            HttpResponseMessage getEmployee = client.GetAsync("api/Employee").Result;
            if (getEmployee.IsSuccessStatusCode)
            {
                emps = getEmployee.Content.ReadAsAsync>().Result.ToList();

                return Json(emps,JsonRequestBehavior.AllowGet) ;
            }
            else
            {
                return null;
            }
        }
}
You can use it under any method.
+3