Java gRPC Server and Client Example

This project demonstrates a basic Java gRPC server and client setup using Maven for build management. It showcases several key gRPC features, including reflection, metadata handling, and error handling. This example aims to provide a practical guide for understanding how microservices can leverage gRPC for efficient communication.

Project Structure

.
├── src/
│   ├── main/
│   │   ├── java/grpc/file/
│   │   |   |   ├── Main.java
│   │   │   ├── examples/
│   │   │   │   ├── GRPCClient.java
│   │   │   │   ├── GRPCServer.java
│   │   ├── proto/
│   │   │   ├── greeter.proto
│   │   │   ├── calculator.proto
├── target/
├── pom.xml
└── README.md

Protocol Buffer Definitions

The project uses two protocol buffer definitions: greeter.proto and calculator.proto.

greeter.proto

syntax = "proto3";

option java_multiple_files = true;
option java_package = "grpc.file.proto";
option java_outer_classname = "GreeterProto";

package greeter;

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

service Farewell {
  rpc SayGoodbye (ByeRequest) returns (ByeReply) {}
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}

message ByeRequest {
  string name = 1;
}

message ByeReply {
  string message = 1;
}

calculator.proto

syntax = "proto3";

option java_multiple_files = true;
option java_package = "grpc.file.proto";
option java_outer_classname = "CalculatorProto";

package calculator;

service Calculator {
  rpc Add (AddRequest) returns (AddResponse);
  rpc Multiply (MultiplyRequest) returns (MultiplyResponse);
}

message AddRequest {
  int32 a = 1;
  int32 b = 2;
}

message AddResponse {
  int32 result = 1;
}

message MultiplyRequest {
  int32 a = 1;
  int32 b = 2;
  int32 c = 3;

}

message MultiplyResponse {
  int32 result = 1;
}