首先让我们定义一个模拟服务器,它在 100 秒后响应 500:
const string address = "http://localhost:9000";
var delay = TimeSpan.FromSeconds(100);
var server = WireMockServer.Start(new WireMockServerSettings { Urls = new[] { address } });
server
.Given(Request.Create().WithPath("/").UsingPost())
.RespondWith(Response.Create().WithDelay(delay).WithStatusCode(500));
我为此使用了 WireMock.Net。
现在,让我们看看IDiscoveryClient
and DiscoveryClient
:
interface IDiscoveryClient
{
Task<TResponse> SendRequest<TResponse, TPostData>(string url, TPostData data);
}
class DiscoveryClient : IDiscoveryClient
{
private readonly HttpClient httpClient;
public DiscoveryClient(HttpClient httpClient) => this.httpClient = httpClient;
public async Task<TResponse> SendRequest<TResponse, TPostData>(string url, TPostData data)
{
var content = new StringContent(JsonConvert.SerializeObject(data), Encoding.UTF8);
var response = await httpClient.PostAsync(url, content);
response.EnsureSuccessStatusCode();
var rawData = await response.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<TResponse>(rawData);
}
}
class TestRequest { public string Content { get; set; } }
class TestResponse { public string Data { get; set; } }
我使用 json 而不是 xml,但从问题的角度来看这并不重要。
最后让我们连接 DI 并发出请求:
AsyncTimeoutPolicy<HttpResponseMessage> timeoutPolicy =
Policy.TimeoutAsync<HttpResponseMessage>(5, TimeoutStrategy.Pessimistic);
IServiceCollection services = new ServiceCollection();
services.AddHttpClient<IDiscoveryClient, DiscoveryClient>()
.AddPolicyHandler(timeoutPolicy);
ServiceProvider serviceProvider = services.BuildServiceProvider();
var client = serviceProvider.GetService<IDiscoveryClient>();
Stopwatch sw = Stopwatch.StartNew();
try
{
TestResponse res = await client.SendRequest<TestResponse, TestRequest>(address, new TestRequest { Content = "Test"});
}
catch (TimeoutRejectedException ex)
{
sw.Stop();
Console.WriteLine(sw.Elapsed);
}
打印输出将是这样的:
00:00:05.0296804
好消息是它也适用于Optimistic
策略Pessimistic
。