class GrpcServerService extends SimpleGrpc.SimpleImplBase {

    @Override
    public void sayHello(final HelloRequest req, final StreamObserver<HelloReply> responseObserver) {<FILL_FUNCTION_BODY>}

}

        final HelloReply reply = HelloReply.newBuilder().setMessage("Hello ==> " + req.getName()).build();
        responseObserver.onNext(reply);
        responseObserver.onCompleted();
    
<no_super_class>