public static void main(String[] args) throws Exception {
        TikaGrpcServer server = new TikaGrpcServer();
        JCommander commander = JCommander
                .newBuilder()
                .addObject(server)
                .build();

        commander.parse(args);

        if (server.help) {
            commander.usage();
            return;
        }

        server.start();
        server.blockUntilShutdown();
    }
Main launches the server from the command line.
tika-grpc/src/main/java/org/apache/tika/pipes/grpc/TikaGrpcServer.java