Get data from REST API using .NET core

Question

I am trying to get data from REST API using HttpClient, but I have an issue. Using the same service but from Console Application, everything works fine.

From Controller everything works fine, but when GetAsync(url) method from HttpHandler is calling, it looks like something works in the background but nothing happen..

This is my service:

public class UserService : IUsersService
{
    private const string url = "https://jsonplaceholder.typicode.com/users";
    private IHttpHandler httpHandler;

    public UserService(IHttpHandler httpHandler)
    {
        this.httpHandler = httpHandler;
    }

    public List<User> GetAllUsers()
    {
        HttpResponseMessage response = httpHandler.Get(url);

        if (response.IsSuccessStatusCode)
        {
            return response.Content.ReadAsAsync<List<User>>().Result;
        }

        //Nice to add Logging system that we cannot connect into following URL
        return new List<User>();
    }

    public User GetUserById(int userId)
    {
        HttpResponseMessage response = httpHandler.Get(
            string.Concat(url,"?id=",userId));

        if (response.IsSuccessStatusCode)
        {
            return response.Content.ReadAsAsync<List<User>>().Result.FirstOrDefault();
        }

        //Nice to add Logging system that we cannot connect into following URL
        return null;
    }
}

This is my Controller (using WEB API controller, httpClient is not getting data from REST API)

public class UsersController : ApiController
{
    IUsersService userService;

    public UsersController(IUsersService userService)
    {
        this.userService = userService;
    }

    public List<User> GetUsers()
    {
        return userService.GetAllUsers();
    }

    public User GetUser(int userId)
    {
        return userService.GetUserById(userId);
    }
}

And this is my HttpHandler which is currently using HttpClient:

public class HttpHandler : IHttpHandler
{
    private HttpClient client = new HttpClient();

    public HttpResponseMessage Get(string url)
    {
        return GetAsync(url).Result;
    }

    public HttpResponseMessage Post(string url, HttpContent content)
    {
        return PostAsync(url, content).Result;
    }

    public async Task<HttpResponseMessage> GetAsync(string url)
    {
        return await client.GetAsync(url);
    }

    public async Task<HttpResponseMessage> PostAsync(string url, HttpContent content)
    {
        return await client.PostAsync(url, content);
    }
}

This is my console Application which is working well and shows correct result:

class Program
{
    static void Main(string[] args)
    {
        HttpHandler handler = new HttpHandler();
        UserService service = new UserService(handler);

        var users = service.GetAllUsers();

        Console.WriteLine(users[0].Email);
        Console.ReadKey();
    }
}

I don't really know, what could be a problem.

score 0 · Answer 1 · answered Oct 07 '18 at 08:04

During digging network, I found the solution to my problem https://stackoverflow.com/a/10369275/5002910

In the HttpHandler class in the GetAsync method I have to return return await client.GetAsync(url).ConfigureAwait(continueOnCapturedContext:false);

Get data from REST API using .NET core

1 Answers1