HttpClientStudy/HttpClientStudy.Core/HttpError.cs

using HttpClientStudy.Config;

using Microsoft.Extensions.Options;

namespace HttpClientStudy.Core
{
    /// <summary>
    /// Http 错误处理
    /// <list type="number">
    ///     <listheader>
    ///         <term>常见方式</term>
    ///         <description>(仅个人见解)</description>
    ///     </listheader>
    ///     <item>
    ///         <term>HtppClient 提供的状态码、EnsureSuccessStatusCode()等机制</term>
    ///         <description>(适用HttpClient内部错误)</description>
    ///     </item>
    ///     <item>
    ///         <term>Try Catch 方式</term>
    ///         <description>(适用外部)</description>
    ///      </item>
    ///      <item>
    ///         <term>HttpClient 管道</term>
    ///         <description>(统一处理)</description>
    ///      </item>
    ///      <item>
    ///         <term>使用 Polly 类库</term>
    ///         <description>(更多功能,也可结合HttpClient管道)</description>
    ///      </item>
    /// </list>
    /// </summary>
    /// <remarks>
    ///  错误处理
    /// </remarks>
    public class HttpError
    {
        // 定义一个 HttpClient 共享实例
        public static HttpClient HttpClient = new HttpClient(new SocketsHttpHandler() { PooledConnectionLifetime = TimeSpan.FromMinutes(1) })
        {
            BaseAddress = new Uri(WebApiConfigManager.GetWebApiConfig().BaseUrl)
        };

        /// <summary>
        /// 未知主机错误
        /// </summary>
        /// <returns></returns>
        public async Task<HttpStatusCode> UnknownHostAsync()
        {
            var response = await HttpClient.GetAsync("http://www.unknowhost_nonono.com/404.html");

            return response.StatusCode;
        }

        /// <summary>
        /// 没有服务(WebApi服务未启动)
        /// </summary>
        /// <returns></returns>
        public async Task<HttpStatusCode> NoServiceAsync()
        {
            try 
            {
                var response = await HttpClient.GetAsync("http://localhost:30");
            }
            catch (Exception ex)
            {
                // 捕获异常,处理
                await Console.Out.WriteLineAsync(ex.Message );
                throw;
            }
           
            return HttpStatusCode.OK;
        }

        /// <summary>
        /// 404错误
        /// </summary>
        /// <returns></returns>
        public async Task<HttpStatusCode> Http404Async()
        {
            var response = await HttpClient.GetAsync("/404.html");
            return response.StatusCode;
        }

        /// <summary>
        /// 服务器错误
        /// </summary>
        /// <returns></returns>
        public async Task<HttpStatusCode> Http500Async()
        {
            var response = await HttpClient.GetAsync("/api/ErrorDemo/Error500");
            return response.StatusCode;
        }
    }
}