@Override
  public void handle(HttpExchange exchange) throws IOException {

    UpdateContact_Params params =
        (UpdateContact_Params) xmlStream.fromXML(exchange.getRequestBody());
    Contact contact = params.getContact();

    try {
      ServerFacade.updateContact(contact);
    } catch (ServerException e) {
      logger.log(Level.SEVERE, e.getMessage(), e);
      exchange.sendResponseHeaders(HttpURLConnection.HTTP_INTERNAL_ERROR, -1);
      return;
    }

    exchange.sendResponseHeaders(HttpURLConnection.HTTP_OK, -1);
  }