System.Text.Json based formatters

src/Mvc/Mvc.Core/ref/Microsoft.AspNetCore.Mvc.Core.netcoreapp3.0.cs

@@ -876,6 +876,7 @@ public MvcOptions() { }
         public bool RequireHttpsPermanent { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool RespectBrowserAcceptHeader { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool ReturnHttpNotAcceptable { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
+        public System.Text.Json.Serialization.JsonSerializerOptions SerializerOptions { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
         public int? SslPort { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool SuppressAsyncSuffixInActionNames { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public bool SuppressInputFormatterBuffering { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
@@ -1855,6 +1856,21 @@ public StringOutputFormatter() { }
         public override bool CanWriteResult(Microsoft.AspNetCore.Mvc.Formatters.OutputFormatterCanWriteContext context) { throw null; }
         public override System.Threading.Tasks.Task WriteResponseBodyAsync(Microsoft.AspNetCore.Mvc.Formatters.OutputFormatterWriteContext context, System.Text.Encoding encoding) { throw null; }
     }
+    public partial class SystemTextJsonInputFormatter : Microsoft.AspNetCore.Mvc.Formatters.TextInputFormatter, Microsoft.AspNetCore.Mvc.Formatters.IInputFormatterExceptionPolicy
+    {
+        public SystemTextJsonInputFormatter(Microsoft.AspNetCore.Mvc.MvcOptions options) { }
+        Microsoft.AspNetCore.Mvc.Formatters.InputFormatterExceptionPolicy Microsoft.AspNetCore.Mvc.Formatters.IInputFormatterExceptionPolicy.ExceptionPolicy { get { throw null; } }
+        public System.Text.Json.Serialization.JsonSerializerOptions SerializerOptions { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        [System.Diagnostics.DebuggerStepThroughAttribute]
+        public sealed override System.Threading.Tasks.Task<Microsoft.AspNetCore.Mvc.Formatters.InputFormatterResult> ReadRequestBodyAsync(Microsoft.AspNetCore.Mvc.Formatters.InputFormatterContext context, System.Text.Encoding encoding) { throw null; }
+    }
+    public partial class SystemTextJsonOutputFormatter : Microsoft.AspNetCore.Mvc.Formatters.TextOutputFormatter
+    {
+        public SystemTextJsonOutputFormatter(Microsoft.AspNetCore.Mvc.MvcOptions options) { }
+        public System.Text.Json.Serialization.JsonSerializerOptions SerializerOptions { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        [System.Diagnostics.DebuggerStepThroughAttribute]
+        public sealed override System.Threading.Tasks.Task WriteResponseBodyAsync(Microsoft.AspNetCore.Mvc.Formatters.OutputFormatterWriteContext context, System.Text.Encoding selectedEncoding) { throw null; }
+    }
     public abstract partial class TextInputFormatter : Microsoft.AspNetCore.Mvc.Formatters.InputFormatter
     {
         protected static readonly System.Text.Encoding UTF16EncodingLittleEndian;

src/Mvc/Mvc.Formatters.Xml/src/MediaTypeHeaderValues.cs → src/Mvc/Mvc.Core/src/Formatters/MediaTypeHeaderValues.cs

@@ -3,10 +3,19 @@
 
 using Microsoft.Net.Http.Headers;
 
-namespace Microsoft.AspNetCore.Mvc.Formatters.Xml
+namespace Microsoft.AspNetCore.Mvc.Formatters
 {
     internal static class MediaTypeHeaderValues
     {
+        public static readonly MediaTypeHeaderValue ApplicationJson
+            = MediaTypeHeaderValue.Parse("application/json").CopyAsReadOnly();
+
+        public static readonly MediaTypeHeaderValue TextJson
+            = MediaTypeHeaderValue.Parse("text/json").CopyAsReadOnly();
+
+        public static readonly MediaTypeHeaderValue ApplicationAnyJsonSyntax
+            = MediaTypeHeaderValue.Parse("application/*+json").CopyAsReadOnly();
+
         public static readonly MediaTypeHeaderValue ApplicationXml
             = MediaTypeHeaderValue.Parse("application/xml").CopyAsReadOnly();
 

src/Mvc/Mvc.Core/src/Formatters/SystemTextJsonInputFormatter.cs

@@ -0,0 +1,102 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.IO;
+using System.Text;
+using System.Text.Json.Serialization;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.Formatters.Json;
+
+namespace Microsoft.AspNetCore.Mvc.Formatters
+{
+    /// <summary>
+    /// A <see cref="TextInputFormatter"/> for JSON content that uses <see cref="JsonSerializer"/>.
+    /// </summary>
+    public class SystemTextJsonInputFormatter : TextInputFormatter, IInputFormatterExceptionPolicy
+    {
+        /// <summary>
+        /// Initializes a new instance of <see cref="SystemTextJsonInputFormatter"/>.
+        /// </summary>
+        /// <param name="options">The <see cref="MvcOptions"/>.</param>
+        public SystemTextJsonInputFormatter(MvcOptions options)
+        {
+            SerializerOptions = options.SerializerOptions;
+
+            SupportedEncodings.Add(UTF8EncodingWithoutBOM);
+            SupportedEncodings.Add(UTF16EncodingLittleEndian);
+
+            SupportedMediaTypes.Add(MediaTypeHeaderValues.ApplicationJson);
+            SupportedMediaTypes.Add(MediaTypeHeaderValues.TextJson);
+            SupportedMediaTypes.Add(MediaTypeHeaderValues.ApplicationAnyJsonSyntax);
+        }
+
+        /// <summary>
+        /// Gets the <see cref="JsonSerializerOptions"/> used to configure the <see cref="JsonSerializer"/>.
+        /// </summary>
+        /// <remarks>
+        /// A single instance of <see cref="SystemTextJsonInputFormatter"/> is used for all JSON formatting. Any
+        /// changes to the options will affect all input formatting.
+        /// </remarks>
+        public JsonSerializerOptions SerializerOptions { get; }
+
+        /// <inheritdoc />
+        InputFormatterExceptionPolicy IInputFormatterExceptionPolicy.ExceptionPolicy => InputFormatterExceptionPolicy.MalformedInputExceptions;
+
+        /// <inheritdoc />
+        public sealed override async Task<InputFormatterResult> ReadRequestBodyAsync(
+            InputFormatterContext context,
+            Encoding encoding)
+        {
+            if (context == null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            if (encoding == null)
+            {
+                throw new ArgumentNullException(nameof(encoding));
+            }
+
+            var httpContext = context.HttpContext;
+            var inputStream = GetInputStream(httpContext, encoding);
+
+            object model;
+            try
+            {
+                model = await JsonSerializer.ReadAsync(inputStream, context.ModelType, SerializerOptions);
+            }
+            finally
+            {
+                if (inputStream is TranscodingReadStream transcoding)
+                {
+                    transcoding.Dispose();
+                }
+            }
+
+            if (model == null && !context.TreatEmptyInputAsDefaultValue)
+            {
+                // Some nonempty inputs might deserialize as null, for example whitespace,
+                // or the JSON-encoded value "null". The upstream BodyModelBinder needs to
+                // be notified that we don't regard this as a real input so it can register
+                // a model binding error.
+                return InputFormatterResult.NoValue();
+            }
+            else
+            {
+                return InputFormatterResult.Success(model);
+            }
+        }
+
+        private Stream GetInputStream(HttpContext httpContext, Encoding encoding)
+        {
+            if (encoding.CodePage == Encoding.UTF8.CodePage)
+            {
+                return httpContext.Request.Body;
+            }
+
+            return new TranscodingReadStream(httpContext.Request.Body, encoding);
+        }
+    }
+}

src/Mvc/Mvc.Core/src/Formatters/SystemTextJsonOutputFormatter.cs

@@ -0,0 +1,86 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.IO;
+using System.Text;
+using System.Text.Json.Serialization;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.Formatters.Json;
+
+namespace Microsoft.AspNetCore.Mvc.Formatters
+{
+    /// <summary>
+    /// A <see cref="TextOutputFormatter"/> for JSON content that uses <see cref="JsonSerializer"/>.
+    /// </summary>
+    public class SystemTextJsonOutputFormatter : TextOutputFormatter
+    {
+
+        /// <summary>
+        /// Initializes a new <see cref="SystemTextJsonOutputFormatter"/> instance.
+        /// </summary>
+        /// <param name="options">The <see cref="MvcOptions"/>.</param>
+        public SystemTextJsonOutputFormatter(MvcOptions options)
+        {
+            SerializerOptions = options.SerializerOptions;
+
+            SupportedEncodings.Add(Encoding.UTF8);
+            SupportedEncodings.Add(Encoding.Unicode);
+            SupportedMediaTypes.Add(MediaTypeHeaderValues.ApplicationJson);
+            SupportedMediaTypes.Add(MediaTypeHeaderValues.TextJson);
+            SupportedMediaTypes.Add(MediaTypeHeaderValues.ApplicationAnyJsonSyntax);
+        }
+
+        /// <summary>
+        /// Gets the <see cref="JsonSerializerOptions"/> used to configure the <see cref="JsonSerializer"/>.
+        /// </summary>
+        /// <remarks>
+        /// A single instance of <see cref="SystemTextJsonOutputFormatter"/> is used for all JSON formatting. Any
+        /// changes to the options will affect all output formatting.
+        /// </remarks>
+        public JsonSerializerOptions SerializerOptions { get; }
+
+        /// <inheritdoc />
+        public sealed override async Task WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
+        {
+            if (context == null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            if (selectedEncoding == null)
+            {
+                throw new ArgumentNullException(nameof(selectedEncoding));
+            }
+
+            var httpContext = context.HttpContext;
+
+            var writeStream = GetWriteStream(httpContext, selectedEncoding);
+            try
+            {
+                await JsonSerializer.WriteAsync(context.Object, context.ObjectType, writeStream, SerializerOptions);
+                await writeStream.FlushAsync();
+            }
+            finally
+            {
+                if (writeStream is TranscodingWriteStream transcoding)
+                {
+                    transcoding.Dispose();
+                }
+            }
+        }
+
+        private Stream GetWriteStream(HttpContext httpContext, Encoding selectedEncoding)
+        {
+            if (selectedEncoding.CodePage == Encoding.UTF8.CodePage)
+            {
+                // JsonSerializer does not write a BOM. Therefore we do not have to handle it
+                // in any special way.
+                return httpContext.Response.Body;
+            }
+
+            return new TranscodingWriteStream(httpContext.Response.Body, selectedEncoding);
+        }
+    }
+}