使用Polly和Typed Client刷新令牌 [英] Refresh Token using Polly with Typed Client

问题描述

我有一个在服务中配置的Typed Client，并且我正在使用Polly进行临时故障的重试.

I have a Typed Client which i have configured in the services and i am using Polly to make retries for transient faults.

目标:我想利用Polly实现刷新令牌，只要目标站点收到401响应，我都希望Polly刷新令牌并再次继续初始请求.

Aim: I want to make use of Polly to implement refresh token, whenever there is a 401 response from the target site, i want Polly to refresh the token and continue the initial request again.

问题是类型客户端具有所有api方法和刷新令牌方法，当从类型客户端发起请求时，如何再次访问类型客户端以调用刷新令牌并继续初始请求?

The problem is the typed client has all the api methods and the refresh token method, when the request is initiated from the typed client how do i access the typed client again to call the refresh token and continue the initial request?

onRetry中的上下文"为将任何对象添加到字典中提供了一些支持，但是我无法访问SetPolicyExecutionContext('someContext')方法，并且我不想在发起调用之前将其添加到所有方法中因为有很多API.

The 'Context' in onRetry provides some support to add any object to the dictionary, but i am unable to access the SetPolicyExecutionContext('someContext') method and i do not want to add this on all the methods before initiating the call as there's whole lot of API.

// In Service Configuration

// Refresh token policy

var refreshTokenPolicy = Polly.Policy.HandleResult<HttpResponseMessage>(r => r.StatusCode == HttpStatusCode.Unauthorized)
.RetryAsync(1, (response, retrycount, context)) =>
{
    if(response.Result.StatusCode == HttpStatusCode.Unauthorized)
    {
         // Perform refresh token
    }
}

// Typed Client 
services.AddHttpClient<TypedClient>();

public class TypedClient
{
    private static HttpClient _client;
    public TypedClient(HttpClient client)
    {
        _client = client;
    }

    public string ActualCall()
    {
        // some action
    }

    public string RefreshToken()
    {
        // Refresh the token and return
    }
}

推荐答案

您可以使用AddPolicyHandler，它的重载可以通过IServiceProvider.因此，您所需要做的就是:

You can useAddPolicyHandler which has an overload that passesIServiceProvider. So all you need to do is something like:

services.AddHttpClient<TypedClient>()
    .AddPolicyHandler((provider, request) =>
    {
        return Policy.HandleResult<HttpResponseMessage>(r => r.StatusCode == HttpStatusCode.Unauthorized)
            .RetryAsync(1, (response, retryCount, context) =>
            {
                var client = provider.GetRequiredService<TypedClient>();
                // refresh auth token.
            });
        });
    });

这篇关于使用Polly和Typed Client刷新令牌的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！