- A+
所属分类：.NET技术
gRPC JSON转码
gRPC JSON 转码允许浏览器应用调用 gRPC 服务，就像它们是使用 JSON 的 RESTful API 一样。
- 浏览器应用不需要生成 gRPC 客户端或了解 gRPC 的任何信息。
- 通过使用 HTTP 元数据注释 .proto 文件，可从 gRPC 服务自动创建 RESTful API。
- 使应用可以同时支持 gRPC 和 JSON Web API，而无需重复为两者生成单独的服务。
OpenAPI与gRPC Server
OpenAPI（以前称为 Swagger）是一个与语言无关的规范，用于描述 API。 gRPC JSON 转码支持从转码 REST ful的 API 生成 OpenAPI。
实现Server端
通过VS新增GRPC Server，新增nuget包
<ItemGroup> <PackageReference Include="Grpc.AspNetCore" Version="2.49.0" /> <PackageReference Include="Microsoft.AspNetCore.Grpc.JsonTranscoding" Version="7.0.0" /> <PackageReference Include="Microsoft.AspNetCore.Grpc.Swagger" Version="0.3.0" /> </ItemGroup>
为api生成用于OpenAPI的注释XML文件，在Server.csproj文件中新增以下配置
<GenerateDocumentationFile>true</GenerateDocumentationFile>
Server的Program.cs中，开启JSON转码与Swagger
var builder = WebApplication.CreateBuilder(args); // 开启JSON转码 builder.Services.AddGrpc().AddJsonTranscoding(); // 配置Swagger builder.Services.AddGrpcSwagger(); builder.Services.AddSwaggerGen(c => { c.SwaggerDoc("v1", new OpenApiInfo { Title = "gRPC transcoding", Version = "v1" }); var filePath = Path.Combine(System.AppContext.BaseDirectory, "GrpcService4.xml"); c.IncludeXmlComments(filePath); c.IncludeGrpcXmlComments(filePath, includeControllerXmlComments: true); }); var app = builder.Build(); //开启Swagger app.UseSwagger(); app.UseSwaggerUI(c => { c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1"); }); app.MapGrpcService<GreeterService>(); app.MapGet("/", () => "Communication with gRPC endpoints must be made through a gRPC client. To learn how to create a client, visit: https://go.microsoft.com/fwlink/?linkid=2086909"); app.Run();
下载GRPC JSON转码依赖的proto文件
https://github.com/dotnet/aspnetcore/blob/main/src/Grpc/JsonTranscoding/test/testassets/Sandbox/google/api/http.proto
https://github.com/dotnet/aspnetcore/blob/main/src/Grpc/JsonTranscoding/test/testassets/Sandbox/google/api/annotations.proto
并将文件放到项目的google/api/文件夹中。
修改greet.proto文件，通过option开启http选项，以一个get方法和一个post方法举例
syntax = "proto3"; import "google/api/annotations.proto"; option csharp_namespace = "GrpcService4"; package greet; // The greeting service definition. service Greeter { // Sends a greeting rpc SayHello (HelloRequest) returns (HelloReply){ option (google.api.http) = { get: "/v1/greeter/{name}" }; }; // Sends a greeting rpc SayHelloPost (HelloRequestPost) returns (HelloReply){ option (google.api.http) = { post: "/v1/greeter/post", body:"data" }; }; } // The request message containing the user's name. message HelloRequest { string name = 1; } // The request message containing the user's name. message HelloRequestPost { HelloRequestPostData data = 1; } message HelloRequestPostData{ string name = 1; string gender = 2; } // The response message containing the greetings. message HelloReply { string message = 1; }
然后实现Server
using Grpc.Core; using GrpcService4; namespace GrpcService4.Services { public class GreeterService : Greeter.GreeterBase { private readonly ILogger<GreeterService> _logger; public GreeterService(ILogger<GreeterService> logger) { _logger = logger; } public override Task<HelloReply> SayHello(HelloRequest request, ServerCallContext context) { return Task.FromResult(new HelloReply { Message = "Hello " + request.Name }); } public override Task<HelloReply> SayHelloPost(HelloRequestPost request, ServerCallContext context) { return Task.FromResult(new HelloReply { Message = "Hello " + request.Data.Name }); } } }
至此server的json转码开启完成，运行服务，访问swagger，即可尝试http方式请求
在支持http方式的请求的情况下，同时支持grpc请求。
实现Client端
新增控制台项目，添加以下nuget
<ItemGroup> <PackageReference Include="Google.Protobuf" Version="3.21.9" /> <PackageReference Include="Grpc.Net.Client" Version="2.49.0" /> <PackageReference Include="Microsoft.AspNetCore.Grpc.JsonTranscoding" Version="7.0.0" /> <PackageReference Include="Grpc.Tools" Version="2.50.0"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets> </PackageReference> </ItemGroup>
包含与server端相同的proto文件
<ItemGroup> <Protobuf Include="Protosgreet.proto" GrpcServices="Client" /> </ItemGroup>
尝试请求Server
static async Task Main(string[] args) { using var channel = GrpcChannel.ForAddress("https://localhost:7167"); var client = new Greeter.GreeterClient(channel); var reply = await client.SayHelloAsync(new HelloRequest { Name = "GreeterClient" }); Console.WriteLine("Greeting: " + reply.Message); var replyPost = await client.SayHelloPostAsync(new HelloRequestPost { Data = new HelloRequestPostData { Name = "111" } }); Console.WriteLine("Greeting: " + replyPost.Message); Console.WriteLine("Press any key to exit..."); Console.ReadKey(); }
source code: https://github.com/cysnet/grpc-json-transcoding
