I read this article about HttpClientFactory. But i couldn't find a answer for my question. Is it bad approach to use HttpClientFactory in a singleton service to send request to somewhere?
My Program.cs:
builder.Services.AddSingleton<TestService>();
builder.Services.AddTransient<HttpRequestDelegatingHandler>();
builder.Services.AddHttpClient("test", client =>
{
client.BaseAddress = new Uri("https://jsonplaceholder.typicode.com");
}).AddHttpMessageHandler<HttpRequestDelegatingHandler>();
And my Test Service:
public class TestService
{
public Guid InstanceId { get; } = Guid.NewGuid();
private readonly **IHttpClientFactory _factory;**
private readonly ILogger<TestController> _logger;
public TestService(IHttpClientFactory factory, ILogger<TestController> logger)
{
**_factory = factory;**
_logger = logger;
}
public async Task<string> GetAsync()
{
// Get the scoped service's ID
_logger.LogInformation("Service ID in controller {InstanceId}", InstanceId);
// Retrieve an instance of the test client, and send a request
var client = _factory.CreateClient("test");
var result = await client.GetAsync("posts");
// Just return a response, we're not interested in this bit for now
result.EnsureSuccessStatusCode();
return await result.Content.ReadAsStringAsync();
}
}
I created a delegating handler to understand what is going on and i didn't notice any issues.
It is fine to use IHttpClientFactory inside a Singleton service, As a side point, all HttpClient instances that are created by the client factory are meant to be short-lived, then better to use using statement like this:
public async Task<string> GetAsync()
{
//...
// make sure the httpclient will be disposed
using var client = _factory.CreateClient("test");
var result = await client.GetAsync("posts");
// ...
}
Please consider reading this MS doc as well: