Update ValidationEndpointFilterFactory to use type-safe DI for JsonOptions

Co-authored-by: captainsafia <[email protected]>

Author: Copilot

src/Http/Routing/src/ValidationEndpointFilterFactory.cs

@@ -6,7 +6,7 @@
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Reflection;
-using System.Text.Json;
+using Microsoft.AspNetCore.Http.Json;
 using Microsoft.AspNetCore.Http.Metadata;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
@@ -56,18 +56,9 @@ public static EndpointFilterDelegate Create(EndpointFilterFactoryContext context
         {
             ValidateContext? validateContext = null;
 
-            // JsonOptions will be retrieved from DI to set the SerializerOptions
-        var jsonOptionsType = Type.GetType("Microsoft.AspNetCore.Http.Json.JsonOptions, Microsoft.AspNetCore.Http.Extensions");
-        JsonSerializerOptions? serializerOptions = null;
-        if (jsonOptionsType is not null)
-        {
-            var jsonOptions = context.HttpContext.RequestServices.GetService(jsonOptionsType);
-            if (jsonOptions is not null)
-            {
-                var serializerOptionsProperty = jsonOptionsType.GetProperty("SerializerOptions");
-                serializerOptions = serializerOptionsProperty?.GetValue(jsonOptions) as JsonSerializerOptions;
-            }
-        }
+            // Get JsonOptions from DI
+            var jsonOptions = context.HttpContext.RequestServices.GetService<IOptions<JsonOptions>>();
+            var serializerOptions = jsonOptions?.Value?.SerializerOptions;
 
             for (var i = 0; i < context.Arguments.Count; i++)
             {