Refactored.

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ExceptionHandling/AbpExceptionFilter.cs

@@ -16,9 +16,11 @@ namespace Volo.Abp.AspNetCore.Mvc.ExceptionHandling
         public ILogger<AbpExceptionFilter> Logger { get; set; }
 
         private readonly IExceptionToErrorInfoConverter _errorInfoConverter;
-        private readonly HttpExceptionStatusCodeFinder _statusCodeFinder;
+        private readonly IHttpExceptionStatusCodeFinder _statusCodeFinder;
 
-        public AbpExceptionFilter(IExceptionToErrorInfoConverter errorInfoConverter, HttpExceptionStatusCodeFinder statusCodeFinder)
+        public AbpExceptionFilter(
+            IExceptionToErrorInfoConverter errorInfoConverter,
+            IHttpExceptionStatusCodeFinder statusCodeFinder)
         {
             _errorInfoConverter = errorInfoConverter;
             _statusCodeFinder = statusCodeFinder;
@@ -63,7 +65,7 @@ namespace Volo.Abp.AspNetCore.Mvc.ExceptionHandling
 
         protected virtual void HandleAndWrapException(ExceptionContext context)
         {
-            context.HttpContext.Response.StatusCode = _statusCodeFinder.GetStatusCode(context.HttpContext, context.Exception);
+            context.HttpContext.Response.StatusCode = (int)_statusCodeFinder.GetStatusCode(context.HttpContext, context.Exception);
             context.HttpContext.Response.Headers.Add(new KeyValuePair<string, StringValues>("_AbpErrorFormat", "true"));
 
             context.Result = new ObjectResult(

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ExceptionHandling/AbpExceptionHandlingMiddleware.cs

@@ -60,11 +60,11 @@ namespace Volo.Abp.AspNetCore.Mvc.ExceptionHandling
             _logger.LogException(exception);
 
             var errorInfoConverter = httpContext.RequestServices.GetRequiredService<IExceptionToErrorInfoConverter>();
-            var statusCodeFinder = httpContext.RequestServices.GetRequiredService<HttpExceptionStatusCodeFinder>();
+            var statusCodeFinder = httpContext.RequestServices.GetRequiredService<IHttpExceptionStatusCodeFinder>();
             var jsonSerializer = httpContext.RequestServices.GetRequiredService<IJsonSerializer>();
 
             httpContext.Response.Clear();
-            httpContext.Response.StatusCode = statusCodeFinder.GetStatusCode(httpContext, exception);
+            httpContext.Response.StatusCode = (int)statusCodeFinder.GetStatusCode(httpContext, exception);
             httpContext.Response.OnStarting(_clearCacheHeadersDelegate, httpContext.Response);
             httpContext.Response.Headers.Add(new KeyValuePair<string, StringValues>("_AbpErrorFormat", "true"));  //TODO: Constant
 

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ExceptionHandling/DefaultHttpExceptionStatusCodeFinder.cs

@@ -8,35 +8,35 @@ using Volo.Abp.Validation;
 
 namespace Volo.Abp.AspNetCore.Mvc.ExceptionHandling
 {
-    public class HttpExceptionStatusCodeFinder : ITransientDependency
+    public class DefaultHttpExceptionStatusCodeFinder : IHttpExceptionStatusCodeFinder, ITransientDependency
     {
-        public virtual int GetStatusCode(HttpContext httpContext, Exception exception)
+        public virtual HttpStatusCode GetStatusCode(HttpContext httpContext, Exception exception)
         {
             //TODO: If the exception has error code than we can determine the exception from it!
 
             if (exception is AbpAuthorizationException)
             {
                 return httpContext.User.Identity.IsAuthenticated
-                    ? (int)HttpStatusCode.Forbidden
-                    : (int)HttpStatusCode.Unauthorized;
+                    ? HttpStatusCode.Forbidden
+                    : HttpStatusCode.Unauthorized;
             }
 
             if (exception is AbpValidationException)
             {
-                return (int)HttpStatusCode.BadRequest;
+                return HttpStatusCode.BadRequest;
             }
 
             if (exception is EntityNotFoundException)
             {
-                return (int)HttpStatusCode.NotFound;
+                return HttpStatusCode.NotFound;
             }
 
             if (exception is IBusinessException)
             {
-                return (int)HttpStatusCode.Forbidden;
+                return HttpStatusCode.Forbidden;
             }
 
-            return (int)HttpStatusCode.InternalServerError;
+            return HttpStatusCode.InternalServerError;
         }
     }
 }

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/ExceptionHandling/IHttpExceptionStatusCodeFinder.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Net;
+using Microsoft.AspNetCore.Http;
+
+namespace Volo.Abp.AspNetCore.Mvc.ExceptionHandling
+{
+    public interface IHttpExceptionStatusCodeFinder
+    {
+        HttpStatusCode GetStatusCode(HttpContext httpContext, Exception exception);
+    }
+}