SpringBoot+Kotlin中使用GRPC实现服务通信的示例代码

import com.google.protobuf.gradle.*  
plugins {  
    id("org.springframework.boot") version "2.3.1.RELEASE"  
    id("io.spring.dependency-management") version "1.0.9.RELEASE"  
    id("org.asciidoctor.convert") version "1.5.9.2"  
    kotlin("jvm") version "1.6.0"  
    kotlin("plugin.spring") version "1.6.0"  
    id("com.google.protobuf") version "0.9.2"  
}  
repositories {  
    mavenCentral()  
}  
group = "com.whrss.kotlin-grpc"  
version = "0.0.1-SNAPSHOT"  
java.sourceCompatibility = JavaVersion.VERSION_1_8  
java.targetCompatibility = JavaVersion.VERSION_1_8  
sourceSets.main {  
    java.srcDirs("src/main/kotlin")  
}  
extra["spring-restdocs.version"] = "2.0.5.BUILD-SNAPSHOT"  
val snippetsDir by extra { file("build/generated-snippets") }  
dependencies {  
    implementation("com.google.protobuf:protobuf-java:3.22.2")  
    implementation("io.grpc:grpc-protobuf:1.53.0")  
    implementation("com.google.protobuf:protobuf-kotlin:3.22.2")  
    implementation("io.grpc:grpc-kotlin-stub:1.3.0")  
    implementation("io.grpc:grpc-netty:1.56.1")  
    implementation("io.grpc:grpc-all:1.56.1")  
}  
protobuf {  
    protoc {  
        artifact = "com.google.protobuf:protoc:3.19.4"  
    }  
    plugins {  
        id("grpc") {  
            artifact = "io.grpc:protoc-gen-grpc-java:1.40.1"  
        }  
        id("grpckt") {  
            artifact = "io.grpc:protoc-gen-grpc-kotlin:1.3.0:jdk8@jar"  
        }  
    }  
    // Enable Kotlin generation  
    generateProtoTasks {  
        all().forEach {  
            it.plugins {  
                id("grpc")  
                id("grpckt")  
            }  
        }    }}

syntax = "proto3";  
import "google/api/annotations.proto";  
option java_multiple_files = true;  
package hello_world.v1;  
service HelloWorldService{  
  rpc GetUserInfo (GetUserRequest) returns (GetUserReply) {  
    option (google.api.http) = {  
      get: "/api/v1/users"  
    };  
  }  
}  
message GetUserRequest{  
  // 用户showId  
  string userId = 1;  
}  
message GetUserReply{  
  // 用户showId  
  string userId = 1;  
}

import hello_world.v1.GetUserReply  
import hello_world.v1.GetUserRequest  
import hello_world.v1.HelloWorldServiceGrpcKt  
class Service : HelloWorldServiceGrpcKt.HelloWorldServiceCoroutineImplBase() {  
    override suspend fun getUserInfo(request: GetUserRequest) : GetUserReply {  
        println("getItemStatistics exec")  
        return GetUserReply.newBuilder()  
            .setUserId(request.userId)  
            .build()  
    }  
}

import io.grpc.ServerBuilder  
fun main() {  
    helloServer()  
}  
fun helloServer() {  
    val helloService = Service()  
    val server = ServerBuilder  
        .forPort(15001)  
        .addService(helloService)  
        .build()  
    Runtime.getRuntime().addShutdownHook(Thread {  
        server.shutdown()  
        server.awaitTermination()  
    })  
    server.start()  
    println("server start")  
    server.awaitTermination()  
    println("server restart")  
}

import hello_world.v1.GetUserRequest  
import hello_world.v1.HelloWorldServiceGrpc  
import io.grpc.ManagedChannelBuilder  
fun main() {  
    val channel = ManagedChannelBuilder.forAddress("localhost", 15001).usePlaintext()  
    val stub = HelloWorldServiceGrpc.newBlockingStub(channel.build())  
    val response = stub.getUserInfo(GetUserRequest.newBuilder().setUserId("0").build())  
    println(response)  
}