java-protonats

This is a protoc plugin that generates Java server and client code for NATS microservices.

java-protonats uses the shared protonats package and is protocol compatible with the Go implementation.

Prior experience with Protobuf is greatly recommended, especially to understand how the package and imports work.

Warning

The java plugin is currently in development and does not generate valid or working java client/server code.

Installation

As this plugin is written in Go, you need to have Go installed to be able to install this plugin. You also already need to have the protoc compiler along the Java protobuf plugin installed on your system. After that, you can go ahead and install this plugin using the following command:

go install xiam.li/java-protonats/cmd/protoc-gen-java-nats@latest

To check if the installation was successful, you can run:

protoc-gen-java-nats -v

Usage

Upon installation, you should create a protobuf file that contains a service, similar to how gRPC servers work. An example protobuf file might look like this:

syntax = "proto3";
package your.package;
option go_package = "github.com/user/repo/pb;pb";
option java_multiple_files = true;
option java_package = "me.username.repo.service";

service HelloWorldService {
    rpc HelloWorld(HelloWorldRequest) returns (HelloWorldResponse);
}

message HelloWorldRequest {
    string name = 1;
}

message HelloWorldResponse {
    string message = 1;
}

To generate the Java code for this service, run the following command. This command expects your proto file in a directory called pb in your project.

protoc -I pb --java_out=pb --java-nats_out=pb --java-nats_opt=paths=source_relative pb/hello_world.proto

This obviously requires the protoc compiler to be installed on your system and also having the Java protobuf plugin installed, so that besides the code regarding NATS can be generated, the messages and everything else can also be generated.

Streaming

Streaming is not yet supported, but is planned for the future.