.net webapi 过滤器使用（异常日志）

常用的过滤器有三种：OnAuthorization、ActionFilterAttribute、ExceptionFilterAttribute

本文件主要记录使用ExceptionFilterAttribute记录接口的异常日志，包括请求参数、响应结果，耗时等

直接上代码：

using Newtonsoft.Json;
using ServiceRef;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Http;
using System.Web.Http.ExceptionHandling;
using System.Web.Http.Filters;

namespace WebApi.App_Start
{
    /// <summary>
    /// 异常过滤器
    /// </summary>
    public class ExceptionFilter : ExceptionFilterAttribute
    {       

        ///// <summary>
        ///// 异步写异常
        ///// </summary>
        ///// <param name="actionExecutedContext"></param>
        ///// <param name="cancellationToken"></param>
        //public override async Task OnExceptionAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)
        //{
        //    //1.获取异常信息
        //    string errorMsg = actionExecutedContext.Exception.ToString();

        //    //2.对获取的异常信息进行处理
        //    using (StreamWriter writer = File.AppendText("d:/err.txt"))
        //    {
        //        await writer.WriteLineAsync(errorMsg);
        //    }
        //}

        public override void OnException(HttpActionExecutedContext actionExcutedContext)
        {
            HttpRequestMessage request = actionExcutedContext.Request;
            string controllerName = actionExcutedContext.ActionContext.ControllerContext.ControllerDescriptor.ControllerName;
            string actionName = actionExcutedContext.ActionContext.ActionDescriptor.ActionName;
            string content = request.Content.ReadAsStringAsync().Result;
            string headers = GetCollections(request.Headers);
            string exceptionMessage = actionExcutedContext.Exception.Message;
            string exceptionTrace = actionExcutedContext.Exception.StackTrace;
            string arguments = JsonConvert.SerializeObject(actionExcutedContext.ActionContext.ActionArguments);
            string url = request.RequestUri.AbsoluteUri;
            StringBuilder sb = new StringBuilder();
            sb.AppendFormat("URL:{0}
", url);
            sb.AppendFormat("Controller:{0}
", controllerName);
            sb.AppendFormat("Action:{0}
", actionName);
            sb.AppendFormat("Arguments:{0}
", arguments);
            sb.AppendFormat("Content:{0}
", content);
            sb.AppendFormat("Headers:{0}
", headers);
            sb.AppendFormat("ExceptionMessage:{0}
", exceptionMessage);
            sb.AppendFormat("ExceptionTrace:{0}
", exceptionTrace);
            actionExcutedContext.Response = new HttpResponseMessage() { Content = new StringContent(sb.ToString()), StatusCode = System.Net.HttpStatusCode.InternalServerError };
            //记录日志

            string errMsg = "";
            sb.Clear();
            sb = null;
            base.OnException(actionExcutedContext);
        }
        /// <summary>
        /// 获取Action 参数
        /// </summary>
        /// <param name="Collections"></param>
        /// <returns></returns>
        public string GetCollections(HttpRequestHeaders Collections)
        {
            string Parameters = string.Empty;
            if (Collections == null || Collections.Count() == 0)
            {
                return Parameters;
            }
            foreach (var coll in Collections)
            {
                if (coll.Value.Count() > 0)
                {
                    Parameters += string.Format("{0}={1}&", coll.Key, coll.Value.FirstOrDefault().ToString());
                }
            }
            if (!string.IsNullOrWhiteSpace(Parameters) && Parameters.EndsWith("&"))
            {
                Parameters = Parameters.Substring(0, Parameters.Length - 1);
            }
            return Parameters;
        }
    }
}