/// <summary>
/// Httpclient扩展方法
/// </summary>
/// <param name="services">ioc容器</param>
/// <param name="name">HttpClient 名称(针对不同的服务进行熔断，降级)</param>
/// <param name="action">熔断降级配置</param>
/// <param name="TResult">降级处理错误的结果</param>
/// <returns></returns>
public static IServiceCollection AddPollyHttpClient(this IServiceCollection services, string name, Action <PollyHttpClientOptions> action)
{
// 1、创建选项配置类
PollyHttpClientOptions options = new PollyHttpClientOptions();
action(options);
// 2、封装降级消息
var fallbackResponse = new HttpResponseMessage
{
Content = new StringContent(options.ResponseMessage), // 降级消息
StatusCode = HttpStatusCode.GatewayTimeout // 降级状态码
};
// 2、配置httpClient,熔断降级策略
services.AddHttpClient(name)
//1.1 降级策略
.AddPolicyHandler(Policy <HttpResponseMessage> .HandleInner <Exception>().FallbackAsync(fallbackResponse, async b =>
{
// 1、降级打印异常
Console.WriteLine($"服务{name}开始降级,异常消息：{b.Exception.Message}");
// 2、降级后的数据
Console.WriteLine($"服务{name}降级内容响应：{fallbackResponse.RequestMessage}");
await Task.CompletedTask;
}))
// 1.2 断路器策略
.AddPolicyHandler(Policy <HttpResponseMessage> .Handle <Exception>().CircuitBreakerAsync(options.CircuitBreakerOpenFallCount, TimeSpan.FromSeconds(options.CircuitBreakerDownTime), (ex, ts) =>
{
Console.WriteLine($"服务{name}断路器开启，异常消息：{ex.Exception.Message}");
Console.WriteLine($"服务{name}断路器开启时间：{ts.TotalSeconds}s");
}, () =>
{
Console.WriteLine($"服务{name}断路器关闭");
}, () =>
{
Console.WriteLine($"服务{name}断路器半开启(时间控制，自动开关)");
}))
// 1.3 重试策略
.AddPolicyHandler(Policy <HttpResponseMessage>
.Handle <Exception>()
.RetryAsync(options.RetryCount)
)
// 1.4 超时策略
.AddPolicyHandler(Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(options.TimeoutTime)));
return(services);
}
/// <summary>
/// 注册 Polly HttpClient服务注入IOC容器扩展
/// </summary>
/// <param name="services">ioc容器</param>
/// <param name="httpClientName">HttpClient 名称(针对不同的服务进行熔断，降级)</param>
/// <param name="action">熔断降级配置</param>
/// <param name="TResult">降级处理错误的结果</param>
public static IServiceCollection AddPollyHttpClient(this IServiceCollection services, string httpClientName, Action <PollyHttpClientOptions> action)
{
// 1. 创建选项配置类
var options = new PollyHttpClientOptions();
action(options);
// 2. 配置 HttpClient 各种策略
services.AddHttpClient(httpClientName)
// 1）降级策略
.AddPolicyHandler(Policy <HttpResponseMessage> .HandleInner <Exception>().FallbackAsync(options.httpResponseMessage, async b =>
{
// 1、降级打印异常
Console.WriteLine($"服务{httpClientName}开始降级,异常消息：{b.Exception.Message}");
// 2、降级后的数据
Console.WriteLine($"服务{httpClientName}降级内容响应：{await options.httpResponseMessage.Content.ReadAsStringAsync()}");
await Task.CompletedTask;
}))
// 2) 熔断策略
.AddPolicyHandler(Policy <HttpResponseMessage> .Handle <Exception>().CircuitBreakerAsync(options.CircuitBreakerOpenFallCount, TimeSpan.FromSeconds(options.CircuitBreakerDownTime), (ex, ts) =>
{
Console.WriteLine($"服务{httpClientName}断路器开启，异常消息：{ex.Exception.Message}");
Console.WriteLine($"服务{httpClientName}断路器开启时间：{ts.TotalSeconds}s");
}, () =>
{
Console.WriteLine($"服务{httpClientName}断路器关闭");
}, () =>
{
Console.WriteLine($"服务{httpClientName}断路器半开启(时间控制，自动开关)");
}))
// 2) 重试策略
.AddPolicyHandler(Policy <HttpResponseMessage>
.Handle <Exception>()
.RetryAsync(options.RetryCount)
)
// 1.4 超时策略
.AddPolicyHandler(Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(options.TimeoutTime)));
return(services);
}
public static IServiceCollection AddPollyClient(this IServiceCollection services, string name, Action <PollyHttpClientOptions> action)
{
//创建 选项配置表
PollyHttpClientOptions options = new PollyHttpClientOptions();
action(options);
var fallbackResponse = new HttpResponseMessage
{
//降级消息
Content = new StringContent(options.ResponseMessage),
//降级状态码
StatusCode = HttpStatusCode.GatewayTimeout
};
//2.配置 httpclient熔断降级策略
object addPolicyHandler = services.AddHttpClient(name)
//1.降级策略
.AddPolicyHandler(Policy <HttpResponseMessage> .HandleInner <Exception>().FallbackAsync(fallbackResponse, async b =>
{
//1.降级打印
Console.WriteLine($"服务{name}开始降级，异常消息：{b.Exception.Message}");
//2.降级后的数据
Console.WriteLine($"服务{name}降级内容响应:{fallbackResponse.RequestMessage}");
await Task.CompletedTask;
}))
//2.熔断策略
.AddPolicyHandler(Policy <HttpResponseMessage> .Handle <Exception>().CircuitBreakerAsync(options.CircuitBreakerOpenFallCount, TimeSpan.FromSeconds(options.CircuitBreakerDownTime), (ex, ts) =>
{
Console.WriteLine($"服务{name}断路器开启，异常消息:{ex.Exception.Message}");
Console.WriteLine($"服务{name}断路器开启时间:{ts.TotalSeconds}s");
}, () =>
{
Console.WriteLine($"服务{name}断路器关闭");
}, () =>
{
Console.WriteLine($"服务{name}断路器半开启（时间控制，自动开启）");
}))
//3.重试策略
.AddPolicyHandler(Policy <HttpResponseMessage> .Handle <Exception>().RetryAsync(options.RetryCount))
//4.超时策略
.AddPolicyHandler(Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(options.TimeOut)));
return(services);
}
/// <summary>
/// HttpClient扩展方法
/// </summary>
/// <param name="services">ioc容器</param>
/// <param name="name">HttpClient名称(针对不同的服务进行熔断、降级)</param>
/// <param name="action">熔断降级配置</param>
/// <returns></returns>
public static IServiceCollection AddPollyHttpClientService(this IServiceCollection services, string name, Action <PollyHttpClientOptions> action)
{
//创建选项配置类
PollyHttpClientOptions options = new PollyHttpClientOptions();
action(options);
//配置httpClient，熔断降级策略
//超时->重试->熔断->降级，从下往上，下层被上层捕获
services.AddHttpClient(name)
//降级策略(捕获异常，进行自定义处理)
.AddPolicyHandler(Policy <HttpResponseMessage> .HandleInner <Exception>().FallbackAsync(options.HttpResponseMsg
, async ex =>
{
//降级打印异常
Console.WriteLine($"服务{name}开始降级，异常消息：{ex.Exception.Message}");
//降级后的数据
Console.WriteLine($"服务{name}降级内容响应：{options.HttpResponseMsg.Content.ToString()}");
await Task.CompletedTask;
}))
//断路器策略，熔断机制，设置3次异常开启熔断，10s后下一个请求重新请求微服务，否则不请求微服务直接返回熔断器自定义异常信息
.AddPolicyHandler(Policy <HttpResponseMessage> .Handle <Exception>().CircuitBreakerAsync(options.CircuitBreakerOpenFallCount, TimeSpan.FromSeconds(options.CircuitBreakerDownTime)
, (ex, ts) =>
{
Console.WriteLine($"服务{name}断路器开启，异常消息：{ex.Exception.Message}");
Console.WriteLine($"服务{name}断路器开启时间：{ts.TotalSeconds}s");
}
, () =>
{
Console.WriteLine($"服务{name}断路器关闭");
}
, () =>
{
//每过10s关闭熔断，下个请求微服务，之后重新打开
Console.WriteLine($"服务{name}断路器半开启(时间控制，自动开关)");
}))
//重试策略，失败重试
.AddPolicyHandler(Policy <HttpResponseMessage> .Handle <Exception>().RetryAsync(options.RetryCount))
//超时策略
.AddPolicyHandler(Policy.TimeoutAsync <HttpResponseMessage>(TimeSpan.FromSeconds(options.TimeoutTime)));
return(services);
}
