This generates the Java interfaces out of the service definition from a .proto file. It works with the Protobuf Compiler (protoc).
Normally you don't need to compile the codegen by yourself, since pre-compiled binaries for common platforms are available on Maven Central. However, if the pre-compiled binaries are not compatible with your system, you may want to build your own codegen.
Change to the compiler directory:
$ cd $GRPC_JAVA_ROOT/compiler
To compile the plugin:
$ ../gradlew java_pluginExecutable
To test the plugin with the compiler:
$ ../gradlew test
You will see a PASS if the test succeeds.
To compile a proto file and generate Java interfaces out of the service definitions:
$ protoc --plugin=protoc-gen-java_rpc=build/binaries/java_pluginExecutable/protoc-gen-grpc-java \ --java_rpc_out="$OUTPUT_FILE" --proto_path="$DIR_OF_PROTO_FILE" "$PROTO_FILE"
To generate Java interfaces with protobuf nano:
$ protoc --plugin=protoc-gen-java_rpc=build/binaries/java_pluginExecutable/protoc-gen-grpc-java \ --java_rpc_out=nano=true:"$OUTPUT_FILE" --proto_path="$DIR_OF_PROTO_FILE" "$PROTO_FILE"
This will compile a codegen and put it under your ~/.m2/repository. This will make it available to any build tool that pulls codegens from Maven repostiories.
$ ../gradlew install
Please follow the instructions in DEPLOYING.md under the root directory for deploying the codegen to Maven Central.