Abp vNext异常处理的缺陷/改造方案

吐槽Abp Vnext异常处理！ 哎呀，是一个喷子

目前项目使用Abp VNext开发，免不了要全局处理异常、提示服务器异常信息。

1. Abp官方异常处理

Abp项目默认会启动内置的异常处理，默认不将异常信息发送到客户端。
在AppModule文件ConfigureServices方法中使用以下代码：

 Configure<AbpExceptionHandlingOptions>(options =>
{
      options.SendExceptionsDetailsToClients = true;
});

可将异常信息发送到客户端：如下图：

{
"error": {
"code": null,
"message": "ERROR [42000] [Cloudera][ImpalaODBC] (360) Syntax error occurred during query execution: [HY000] : AnalysisException: Could not resolve column/field reference: 'ug_fed89221846a42dc8427932b2965a020'
",
"details": "OdbcException: ERROR [42000] [Cloudera][ImpalaODBC] (360) Syntax error occurred during query execution: [HY000] : AnalysisException: Could not resolve column/field reference: 'ug_fed89221846a42dc8427932b2965a020'

STACK TRACE: at Gridsum.EAP.Olap.ExecuteQueryLayer.HandleQueryAsync(QueryContext queryContext, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/Olap/ExecuteQueryLayer.cs:line 81
 at Gridsum.EAP.Olap.DistributedCacheLayer.HandleQueryAsync(QueryContext queryContext, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/Olap/DistributedCacheLayer.cs:line 50
 at Gridsum.EAP.DataQuery.AbstractQueryExecutor`1.ExecuteQueryAsync(TQuery query, DistributedCacheEntryOptions options, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/AbstractQueryExecutor.cs:line 60
 at Gridsum.EAP.DataQuery.AbstractQueryExecutor`1.ExecuteQueryAsync(TQuery query, CancellationToken token) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/AbstractQueryExecutor.cs:line 47
 at Gridsum.EAP.Application.UserGroupService.ClearUserGroupUserAsync(UserGroupUpdateUserDto updateDto, String idshort, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.Application/UserGroup/UserGroupService.cs:line 332
 at Gridsum.EAP.Application.UserGroupService.UpdateUserGroupUserAsync(UserGroupUpdateUserDto updateDto, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.Application/UserGroup/UserGroupService.cs:line 370
 at Castle.DynamicProxy.AsyncInterceptorBase.ProceedAsynchronous[TResult](IInvocation invocation, IInvocationProceedInfo proceedInfo "42000] [Cloudera][ImpalaODBC] (360 "42000] [Cloudera][ImpalaODBC] (360) Syntax error occurred during query execution: [HY000] : AnalysisException: Could not resolve column/field reference: 'ug_fed89221846a42dc8427932b2965a020'

STACK TRACE: at Gridsum.EAP.Olap.ExecuteQueryLayer.HandleQueryAsync(QueryContext queryContext, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/Olap/ExecuteQueryLayer.cs:line 81
 at Gridsum.EAP.Olap.DistributedCacheLayer.HandleQueryAsync(QueryContext queryContext, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/Olap/DistributedCacheLayer.cs:line 50
 at Gridsum.EAP.DataQuery.AbstractQueryExecutor`1.ExecuteQueryAsync(TQuery query, DistributedCacheEntryOptions options, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/AbstractQueryExecutor.cs:line 60
 at Gridsum.EAP.DataQuery.AbstractQueryExecutor`1.ExecuteQueryAsync(TQuery query, CancellationToken token) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/AbstractQueryExecutor.cs:line 47
 at Gridsum.EAP.Application.UserGroupService.ClearUserGroupUserAsync(UserGroupUpdateUserDto updateDto, String idshort, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.Application/UserGroup/UserGroupService.cs:line 332
 at Gridsum.EAP.Application.UserGroupService.UpdateUserGroupUserAsync(UserGroupUpdateUserDto updateDto, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.Application/UserGroup/UserGroupService.cs:line 370
 at Castle.DynamicProxy.AsyncInterceptorBase.ProceedAsynchronous[TResult") Syntax error occurred during query execution: [HY000] : AnalysisException: Could not resolve column/field reference: 'ug_fed89221846a42dc8427932b2965a020'

STACK TRACE: at Gridsum.EAP.Olap.ExecuteQueryLayer.HandleQueryAsync(QueryContext queryContext, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/Olap/ExecuteQueryLayer.cs:line 81
 at Gridsum.EAP.Olap.DistributedCacheLayer.HandleQueryAsync(QueryContext queryContext, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/Olap/DistributedCacheLayer.cs:line 50
 at Gridsum.EAP.DataQuery.AbstractQueryExecutor`1.ExecuteQueryAsync(TQuery query, DistributedCacheEntryOptions options, CancellationToken cancellationToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/AbstractQueryExecutor.cs:line 60
 at Gridsum.EAP.DataQuery.AbstractQueryExecutor`1.ExecuteQueryAsync(TQuery query, CancellationToken token) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.DataQuery/AbstractQueryExecutor.cs:line 47
 at Gridsum.EAP.Application.UserGroupService.ClearUserGroupUserAsync(UserGroupUpdateUserDto updateDto, String idshort, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.Application/UserGroup/UserGroupService.cs:line 332
 at Gridsum.EAP.Application.UserGroupService.UpdateUserGroupUserAsync(UserGroupUpdateUserDto updateDto, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.Application/UserGroup/UserGroupService.cs:line 370
 at Castle.DynamicProxy.AsyncInterceptorBase.ProceedAsynchronous[TResult")
 at Volo.Abp.Castle.DynamicProxy.CastleAbpMethodInvocationAdapterWithReturnValue`1.ProceedAsync()
 at Volo.Abp.Validation.ValidationInterceptor.InterceptAsync(IAbpMethodInvocation invocation)
 at Volo.Abp.Castle.DynamicProxy.CastleAsyncAbpInterceptorAdapter`1.InterceptAsync[TResult](IInvocation invocation, IInvocationProceedInfo proceedInfo, Func`3 proceed "TResult")
 at Castle.DynamicProxy.AsyncInterceptorBase.ProceedAsynchronous[TResult](IInvocation invocation, IInvocationProceedInfo proceedInfo "TResult")
 at Volo.Abp.Castle.DynamicProxy.CastleAbpMethodInvocationAdapterWithReturnValue`1.ProceedAsync()
 at Volo.Abp.Auditing.AuditingInterceptor.InterceptAsync(IAbpMethodInvocation invocation)
 at Volo.Abp.Castle.DynamicProxy.CastleAsyncAbpInterceptorAdapter`1.InterceptAsync[TResult](IInvocation invocation, IInvocationProceedInfo proceedInfo, Func`3 proceed "TResult")
 at Castle.DynamicProxy.AsyncInterceptorBase.ProceedAsynchronous[TResult](IInvocation invocation, IInvocationProceedInfo proceedInfo "TResult")
 at Volo.Abp.Castle.DynamicProxy.CastleAbpMethodInvocationAdapterWithReturnValue`1.ProceedAsync()
 at Volo.Abp.Uow.UnitOfWorkInterceptor.InterceptAsync(IAbpMethodInvocation invocation)
 at Volo.Abp.Castle.DynamicProxy.CastleAsyncAbpInterceptorAdapter`1.InterceptAsync[TResult](IInvocation invocation, IInvocationProceedInfo proceedInfo, Func`3 proceed "TResult")
 at Gridsum.EAP.Controllers.UserGroupController.UpdateUserGroupUserAsync(String id, CancellationToken cancelToken) in /home/gitlab-runner/builds/ttRjAPVA/0/eap/website/app/src/Gridsum.EAP.HttpApi/Controllers/UserGroupController.cs:line 320
 at lambda_method3440(Closure , Object )
 at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
 at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
 at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
 at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
 at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
 at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
 at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextExceptionFilterAsync>g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
",
"data": null,
"validationErrors": null
}
}

经过几天倒腾，发现Abp VNext的异常处理有几个问题。

2.Abp异常处理存在的缺陷

1. 并没有如官方所述：自动处理所有异常，需要满足官方所说的任意一个条件
   

这就导致当Controller Action方法返回类型不是object result(并有异常抛出)时，则根本捕获不到异常，这应该算Abp的一个Bug

2. 输出的异常没有TraceId， 不利于日志排查
3. 发送到客户端的日志字段message,detail字段过于详细冗长，不能用于前端显示

当然你也可以使用上面所说的配置：不将异常信息发送到客户端，但这样就因噎废食了。

3. 异常处理的目标

虽然Abp的异常处理有缺陷， 但只是异常信息应用上的缺陷，
Abp异常处理①对异常的划分、②异常信息的本地化、③出现异常时写日志 支持的还是相当好。

我们考虑基于Abp的异常处理做一些扩展，（若扩展不了做一些替换 _..）

1. 对所有Controller-Action方法捕获异常， [修复Abp Bug]
2. 在Abp的异常处理结果中添加 TraceId
3. 希望将服务端异常划分为几大类，简化前端显示；同时也不妨碍开发者查看详细异常信息。

4. 揪出Abp异常处理缺陷的根源

Abp异常处理的核心对象AbpExceptionFilter，实现IAsyncExceptionFilter过滤器, ITransientDependency瞬时注入接口。

这是一个ServiceFilterAttribute, 你可以认为有如下

[ServiceFilter(typeof(AbpExceptionFilter))]

特性，作用在每一个Controller的Action方法上。

一旦某个Controller的Action方法发生异常， 会先后执行如下代码：

public async Task OnExceptionAsync(ExceptionContext context)
{
     if (!ShouldHandleException(context))
     {
          return;
     }
     await HandleAndWrapException(context);
}

1. ShouldHandleException(context) ：监测是否应该处理异常，据查该函数确实存在我上文说的问题：并不能捕获所有的Action方法的异常。
2. HandleAndWrapException(context)： 异常处理步骤：
   • 根据Abp内置的异常类型，自动确定状态码 (这个在Abp官方文档有讲)
   • 序列化异常对象，并向客户端输出如下格式：

    {
"error": {
"code": null,
"message": "ERROR [42000] [Cloudera][ImpalaODBC] (360) Syntax error occurred during query execution: [HY000] : AnalysisException: Could not resolve column/field reference: 'ug_fed89221846a42dc8427932b2965a020'
",
"details":xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx......,
"data": null,
"validationErrors": null
}
}

① 输出的信息，从一开始就没有包含TraceId；
② 这个格式的日志过于详细，message，details字段均不能用于前端显示。

• 写日志，默认异常级别为Error

掌握了以上源码，我们就可以针对性的修改Abp的核心异常处理类AbpExceptionFilter。

5. Abp异常处理顽疾的修复方案

光说不练假把式

Abp的AbpExceptionFilter不是抽象类，没法重载，为大道我们设定的3个目标。
考虑使用针对性的ExceptionFilter替换默认的AbpExceptionFilter。

①. 新建EapExceptionFilter，内容拷贝自AbpExceptionFilter， 并做出如下针对性修改：

②. 在AppModule替换默认的AbpExceptionFilter为新的EapExceptionFilter过滤器：

 context.Services.AddMvc(options =>
{
      options.Filters.ReplaceOne(x=> (x as ServiceFilterAttribute)?.ServiceType?.Name==nameof(AbpExceptionFilter), new ServiceFilterAttribute(typeof(EapExceptionFilter)));  
})

改造的效果如下：

That's All

如果大家真切使用了Abp VNext最新版，

相信我在第2点提到的Abp异常处理的顽疾，Abp使用者会感同身受；

第3点提出的几个目标也是企业级异常处理 要解决的痛点。

此异常处理的思路也可推及到其他非Abp项目.

改造方案在Abp官方github issue上： https://github.com/abpframework/abp/issues/6761
本人经验之谈，如果问题或看法，请不吝赐教！

1. https://github.com/abpframework/abp/blob/dev/framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ExceptionHandling/AbpExceptionFilter.cs
2. https://docs.microsoft.com/en-us/aspnet/core/mvc/controllers/filters?view=aspnetcore-5.0