gRPC Java Tutorial: Building a Spring Boot Service with Maven

gRPC is an open‑source high‑performance RPC framework from Google, based on Protocol Buffers, enabling cross‑language communication and supporting features such as load balancing, health checking and authentication.

The tutorial shows how to define a .proto file with messages Person , Greeting , A1 , A2 and a HelloWorldService offering sayHello and addOperation RPC methods.

Using Maven, the project includes Spring Boot 2.1, grpc-spring-boot-starter , protobuf-maven-plugin and os-maven-plugin ; the pom.xml configures the protobuf compiler and generates Java sources under target/generated-sources/protobuf .

Server code consists of a SpringBootApplication class and a @GRpcService implementation that extends HelloWorldServiceGrpc.HelloWorldServiceImplBase , handling requests with StreamObserver and logging the interactions.

Client code is a Spring component that creates a ManagedChannel to the server (default port 6560 or custom 9090) and uses a blocking stub to call sayHello and addOperation , building request messages with the generated builders.

A JUnit test with @SpringBootTest autowires the client and asserts that the greeting and addition results are correct.

Running mvn compile generates the protobuf classes, then the application can be started and the test executed to verify the gRPC service.