gRPC with Spring boot

This project in composed of a project defining the service contract (according to Protocol Buffers): https://github.com/charroux/gRPCSpring/tree/main/myServiceInterface

And two subprojects:

• one for the service definition: https://github.com/charroux/gRPCSpring/tree/main/myServiceServer
• the other one for the client: https://github.com/charroux/gRPCSpring/tree/main/myServiceClient

https://github.com/charroux/gRPCSpring/blob/main/settings.gradle set the whole project.

Requirements

Java 17.

The Server side

Service definition: https://github.com/charroux/gRPCSpring/blob/main/myServiceInterface/src/main/proto/myService.proto

Project settings: https://github.com/charroux/gRPCSpring/blob/main/myServiceInterface/settings.gradle

build.gradle file: https://github.com/charroux/gRPCSpring/blob/main/myServiceInterface/build.gradle

The servder implementation

Project settings: https://github.com/charroux/gRPCSpring/blob/main/myServiceServer/settings.gradle

build.gradle file: https://github.com/charroux/gRPCSpring/blob/main/myServiceServer/build.gradle

See how the interface definition project is included:

implementation project(':myServiceInterface')

Server port selection: https://github.com/charroux/gRPCSpring/blob/main/myServiceServer/src/main/resources/application.properties

The server implementation: https://github.com/charroux/gRPCSpring/blob/main/myServiceServer/src/main/java/com/example/myServiceServer/MyServiceImpl.java

Notice the annotation:

@GrpcService

Look for

new StreamObserver<Car>

onNext is called each time a car is received.

The client side

A Rest controller: https://github.com/charroux/gRPCSpring/tree/main/myServiceClient/src/main/java/com/example/myServiceClient/web

Using a service class invoquing the gRPC service: https://github.com/charroux/gRPCSpring/blob/main/myServiceClient/src/main/java/com/example/myServiceClient/service/MyService.java

Notice the annotation:

@GrpcClient("myService")

And its corresponding definition: https://github.com/charroux/gRPCSpring/blob/main/myServiceClient/src/main/resources/application.properties

Notice also the server address:

grpc.client.myService.address=localhost:9090

Build the whole project

In the root folder (gRPCSpring):

./gradlew build

See the generated files for the service: https://github.com/charroux/gRPCSpring/tree/main/myServiceInterface/src/generated/main

Launch the server side

In the server folder (myServiceServer):

java -jar build/libs/myServiceServer-0.0.1-SNAPSHOT.jar

Launch the client side

In the client folder (myServiceClient):

java -jar build/libs/myServiceClient-0.0.1-SNAPSHOT.jar

Service remote access: http://localhost:8080/world