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

Question

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

Rijwan Ansari · Answer

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

Sachin Singh · Answer

@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) ; }

Sachin Singh · Answer

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.

Sujeet Raman · Answer

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

Sujeet Raman · Answer

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