Gradle + flatbuffers + grpc + spring boot

Notes

1. Open JDK 17:

           sudo apt install openjdk-17-jdk
           sudo update-alternatives --config java

   The java alternative needs to be Java 17 for Spring boot. This can also be done using gradle properties in your home folder .gradle.

2. Reasonable gradle install for Mint https://www.markaicode.com/gradle-installation-on-linux-mint-21/

3. IntelliJ, change Gradle to be Java 17 (if need be) https://stackoverflow.com/questions/72117858/incompatible-because-this-component-declares-a-component-compatible-with-java-11

4. The flatbuffers compiler needs to be a binary. "flatc" in "fb-lib/flatc", needs to be binary, and 23.3.3. If it is not, build flatc 23.3.3 and put it there.

Build

./gradlew build

Run

To run gRPC server

./gradlew :grpc-server:bootRun

To run a test-app client

./gradlew :grpc-test-app:run

Under hood

Bare minimal set of libraries, plugins and code to run gRPC server. Only official libraries and plugins are used.

fb-lib

Module with library flavour holds schema.fbs, generates java sources and provides transitive dependencies for flatbuffers and grpc

grpc-server

Module with spring boot app, basically spring controls grpc server lifecycle and provides properties

grpc-client

Module with library flavour adds stubs over fb-lib and add UX to generated flatbuffers client

grpc-test-app

Module with application flavour, onliner of grpc-client usage