public GreeterServer(int port) throws IOException {
  this(ServerBuilder.forPort(port), port);
}

public GreeterServer(ServerBuilder<?> serverBuilder, int port) {
  this.port = port;
  server = serverBuilder.addService(new GreeterImpl()).build();
}

public void start() throws IOException {
  server.start();
  logger.info("Server started, listening on " + port);
}