使用自定义响应类处理 .NET5 中的错误

如何解决使用自定义响应类处理 .NET5 中的错误

我来自 Java/Spring 背景，我正在尝试学习 .NET 5。我正在研究 Web API，一切都很好，但不知何故我无法理解或使它工作，我我尝试了一些网上找到的解决方案，但随着多年来的变化，我不知道它们是否不再起作用，或者有更好的方法来做到这一点。

基本上，我想在我的 .NET API 中处理错误。

我的服务有这个代码：

public Users execute(int id)
{
    var foundUser = this.userRepository.findById(id);
    if (foundUser == null)
    {
        throw new HttpException(HttpStatusCode.NotFound,"User not found");
    }
    return foundUser;
}

HttpException 是我创建的自定义异常，因此我可以控制状态代码

using System;
using System.Net;

namespace dotnetex.shared.Errors
{
    public class HttpException : Exception
    {

        public HttpStatusCode Status { get; set; }

        public HttpException(HttpStatusCode status,string msg) : base(msg)
        {
            Status = status;
        }
    }
}

我的启动类有指向我的路由的异常处理程序：

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app,IWebHostEnvironment env)
    {
        app.UseExceptionHandler("/error"); // Add this
[...]

我的路线是这样的

using System.Net;
using Microsoft.AspNetCore.Diagnostics;
using Microsoft.AspNetCore.Mvc;

namespace dotnetex.shared.Errors.Controller
{
    [ApiController]
    public class ErrorController : ControllerBase
    {
        [Route("/error")]
        public IActionResult Error()
        {
            var exception = HttpContext.Features.Get<IExceptionHandlerFeature>();
            HttpException error = (HttpException)exception.Error;
            var statusCode = (int)error.Status;
            return Problem(detail: error.Message,statusCode: statusCode);
        }
    }
}

出于某种原因，当我从“错误”变量中获取 statusCode 时，我的响应被破坏了，我的 Insomnia 告诉我 Error: Transferred a partial file。调试显示我设置了 statusCode 变量。当我通过代码设置一个数字时，事情会按预期工作。

我尝试在 Insomnia、Postman、Chrome 浏览器、CURL 中调用端点。都显示错误

最后，如果可能的话。我想从这个路由返回一个名为 API Error 的自定义错误对象，而不是“问题”，就像这个：

namespace dotnetex.shared.Errors
{
    public class APIError
    {
        private int status_code = 500;
        private string message = "";
        public APIError(int status_code,string message)
        {
            this.status_code = status_code;
            this.message = message;
        }
    }
}

控制台中的异常是：

fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[1]
      An unhandled exception has occurred while executing the request.
      dotnetex.shared.Errors.HttpException: User not found
         at dotnetex.modules.users.Services.Implementations.GetUserByIdService.GetUserByIdService.execute(Int32 id) in /home/matt/Source/net/dotnetexSl/dotnetex/modules/users/Services/Implementations/GetUserByIdService/GetUserByIdService.cs:line 23
         at modules.users.Services.UserServices.GetUserById(Int32 id) in /home/matt/Source/net/dotnetexSl/dotnetex/modules/users/Services/UserServices.cs:line 45
         at modules.users.Controllers.UsersControllers.getSingleUser(Int32 id) in /home/matt/Source/net/dotnetexSl/dotnetex/modules/users/Controllers/UsersControllers.cs:line 53
         at lambda_method1(Closure,Object,Object[] )
         at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncObjectResultExecutor.Execute(IActionResultTypeMapper mapper,ObjectMethodExecutor executor,Object controller,Object[] arguments)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next,Scope& scope,Object& state,Boolean& isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()
      --- End of stack trace from previous location ---
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next,Boolean& isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
      --- End of stack trace from previous location ---
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker,Task lastTask,State next,Scope scope,Object state,Boolean isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker,Task task,IDisposable scope)
         at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint,Task requestTask,ILogger logger)
         at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware,HttpContext context,Task task)
warn: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[4]
      No exception handler was found,rethrowing original exception.
fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HM6S5CSRT4C8",Request id "0HM6S5CSRT4C8:00000002": An unhandled exception was thrown by the application.
      dotnetex.shared.Errors.HttpException: User not found
         at dotnetex.modules.users.Services.Implementations.GetUserByIdService.GetUserByIdService.execute(Int32 id) in /home/matt/Source/net/dotnetexSl/dotnetex/modules/users/Services/Implementations/GetUserByIdService/GetUserByIdService.cs:line 23
         at modules.users.Services.UserServices.GetUserById(Int32 id) in /home/matt/Source/net/dotnetexSl/dotnetex/modules/users/Services/UserServices.cs:line 45
         at modules.users.Controllers.UsersControllers.getSingleUser(Int32 id) in /home/matt/Source/net/dotnetexSl/dotnetex/modules/users/Controllers/UsersControllers.cs:line 53
         at lambda_method1(Closure,Task task)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.HandleException(HttpContext context,ExceptionDispatchInfo edi)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware,Task task)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

如果您能帮我找到解决方案，我将不胜感激。

先谢谢你！

解决方法

我不太确定你在这里问的是什么。如果您使用错误控制器并抛出自定义异常，我会检查您的控制器上的异常类型。

例如，如果您定义一个自定义 HttpException，然后像 Throw new HttpException(HttpStatusCodes.NotFound,"Woah something happened!); 这样抛出该异常，然后会被您的错误控制器捕获。

默认情况下，您捕获的普通 Exception 上没有 status 属性，因此您需要像这样处理它：

[Route("error")]
public ErrorResponseModel Error()
{
    var context = HttpContext.Features.Get<IExceptionHandlerFeature>();
    var exception = context.Error;

    // Handle if the exception is a HttpException
    if(exception is HttpException httpException)
    {
         Response.StatusCode = (int)httpException.status;

         return new ErrorResponseModel(httpException);
    }

    // Handle all other exceptions
    Response.StatusCode = (int)HttpStatusCode.InternalServerError;

    return new ErrorResponseModel(exception);
}

您可以看到我只是定义了自己的错误模型，而不是返回 IActionResult，然后将 Response.StatusCode 设置为我想要的任何值。

这应该会让你开始。

,

ASP.NET Core 5 在处理响应状态代码 NotFound 404 时引入了 breaking-change。使用 ExceptionHandlerOptions.AllowStatusCode404Response 属性。

像这样修复 UseExceptionHandler 方法：

Startup.cs

 public void Configure(IApplicationBuilder app,IWebHostEnvironment env)
 {
    app.UseExceptionHandler(
          new ExceptionHandlerOptions()
          {
              AllowStatusCode404Response = true,// important!
              ExceptionHandlingPath = "/error"                  
          }
      );      
  }