WebApi 打个Attribute 统一处理异常

Posted 2022-10-27 lee576

我们处理异常的时候通常都要写形如以下的代码

try

   xxxxx

catch(Exception ex)

   log.write(ex.Message)

前一段时间看杨中科的视频，其中吐糟了 mvc 的管道机制，当然用在web ui 的渲染上这个还不如做个前后端分离，因为用管道和razor视图引擎去做这些看着就很繁琐，并且很重，整个架构都复杂化了，但是作为一些AOP的处理，管道却非常的好用，下面用一个Atrribute异常过滤器来统一的处理异常，那么每次有异常出现就不用写如上的代码去手动捕获了

using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Web.Http.Filters;

namespace HenryMes.WebApi.App_Start

    /// <summary>
    /// 异常处理
    /// </summary>
    public class OnErrorResponseAttribute : ExceptionFilterAttribute
    
        /// <summary>
        /// 
        /// </summary>
        /// <param name="context"></param>
        public override void OnException(HttpActionExecutedContext context)
        
            var error = string.IsNullOrEmpty(context.Exception.InnerException?.Message) ? context.Exception.Message : context.Exception.InnerException?.Message;
            Utils.LogHelper.GetInstance().Error($@"/context.ActionContext.ControllerContext.ControllerDescriptor.ControllerName/context.ActionContext.ActionDescriptor.ActionName : error");

            if (context.Exception is NotImplementedException)
            
                context.Response = new HttpResponseMessage(HttpStatusCode.NotImplemented);
            
            else if (context.Exception is TimeoutException)
            
                var errorObj = new ErrowMessage()  Result = false, Message = "API调用超时" ;
                context.Response = new HttpResponseMessage()  StatusCode = HttpStatusCode.RequestTimeout, Content = new ObjectContent(typeof(ErrowMessage), errorObj, new JsonMediaTypeFormatter(), "application/json") ;
            
            //.....这里可以根据项目需要返回到客户端特定的状态码。如果找不到相应的异常，统一返回服务端错误500
            else
            
                var errorObj = new ErrowMessage()  Result = false, Message = error ;
                context.Response = new HttpResponseMessage()  StatusCode = HttpStatusCode.BadRequest, Content = new ObjectContent(typeof(ErrowMessage), errorObj, new JsonMediaTypeFormatter(), "application/json") ;
            
            base.OnException(context);
        

        /// <summary>
        /// 
        /// </summary>
        public class ErrowMessage
        
            /// <summary>
            /// 
            /// </summary>
            public bool Result  set; get; 
            /// <summary>
            /// 
            /// </summary>
            public string Message  set; get; 
        
    

以上就是一个异常处理的过滤器，下面的Contronlller只用打上一个标签就不用再去写 try catch 了

        /// <summary>
        /// 
        /// </summary>
        /// <returns></returns>
        [HttpPost]
        [OnErrorResponse]
        public IHttpActionResult Test()
        
            var aaa = 999;
            var b = 333;
            b = 0;
            var c = aaa / b;
            return null;