dart grpc 试用

主要是体验下dart grpc 的集成试用,grpc 对于dart 的支持也是基于了插件生成代码，然后我们可以基于生成的代码创建实现，client 进行调用

参考项目

代码来自官方示例

• proto 定义

syntax = "proto3";

 

option java_multiple_files = true;

option java_package = "io.grpc.examples.helloworld";

option java_outer_classname = "HelloWorldProto";

option objc_class_prefix = "HLW";

 

package helloworld;

 

// The greeting service definition.

service Greeter {

  // Sends a greeting

  rpc SayHello (HelloRequest) returns (HelloReply) {}

}

 

// The request message containing the user's name.

message HelloRequest {

  string name = 1;

}

 

// The response message containing the greetings

message HelloReply {

  string message = 1;

} 

• 生成代码
  注意需要安装protoc 以及 dart grpc 扩展dart pub global activate protoc_plugin

 

protoc --dart_out=grpc:lib/src/generated -Iprotos protos/helloworld.proto

• 效果

 

• server 实现
  server.dart

 

import 'package:grpc/grpc.dart';

import 'package:helloworld/src/generated/helloworld.pbgrpc.dart';

 

// 实现

class GreeterService extends GreeterServiceBase {

  @override

  Future<HelloReply> sayHello(ServiceCall call, HelloRequest request) async {

    return HelloReply()..message = 'Hello, ${request.name}!';

  }

}

// 服务启动

Future<void> main(List<String> args) async {

  final server = Server.create(

    services: [GreeterService()],

    codecRegistry: CodecRegistry(codecs: const [GzipCodec(), IdentityCodec()]),

  );

  await server.serve(port: 50051);

  print('Server listening on port ${server.port}...');

}

• client 实现
  client.dart

 

import 'package:grpc/grpc.dart';

import 'package:helloworld/src/generated/helloworld.pbgrpc.dart';

 

Future<void> main(List<String> args) async {

  // channel  创建

  final channel = ClientChannel(

    'localhost',

    port: 50051,

    options: ChannelOptions(

      credentials: ChannelCredentials.insecure(),

      codecRegistry:

          CodecRegistry(codecs: const [GzipCodec(), IdentityCodec()]),

    ),

  );

  // client stub

  final stub = GreeterClient(channel);

 

  final name = args.isNotEmpty ? args[0] : 'world';

 

  try {

    final response = await stub.sayHello(

      HelloRequest()..name = name,

      options: CallOptions(compression: const GzipCodec()),

    );

    print('Greeter client received: ${response.message}');

  } catch (e) {

    print('Caught error: $e');

  }

  await channel.shutdown();

}

说明

对于一些业务系统（比如基于flutter 开发的桌面应用基于dart grpc 进行数据通信也是一个不错的选择），当然buf 基于protobuf 的connect
协议也是一个不错的选择

参考资料

https://connectrpc.com/
https://github.com/grpc/grpc-dart
https://pub.dev/packages/grpc/install
https://buf.build/
https://grpc.io/docs/languages/dart/quickstart/
https://github.com/grpc/grpc-web