code: private void writeDriverJsonInformation(final HttpServletResponse response) throws IOException {
  
      LOG.log(Level.INFO, "HttpServerReefEventHandler writeDriverJsonInformation invoked.");
  
      try {
        final DriverInfoSerializer serializer =
            Tang.Factory.getTang().newInjector().getInstance(DriverInfoSerializer.class);
        final AvroDriverInfo driverInfo = serializer.toAvro(
            this.reefStateManager.getDriverEndpointIdentifier(), this.reefStateManager.getStartTime(),
            this.reefStateManager.getServicesInfo());
        writeResponse(response, serializer.toString(driverInfo));
      } catch (final InjectionException e) {
        LOG.log(Level.SEVERE, "Error in injecting DriverInfoSerializer.", e);
        writeResponse(response, "Error in injecting DriverInfoSerializer: " + e);
      }
    }
docs: Write Driver Info as JSON string to Response.