public URI adminUrl() {
        ServerConnector adminConnector = null;
        for (Connector connector : jettyServer.getConnectors()) {
            if (ADMIN_SERVER_CONNECTOR_NAME.equals(connector.getName()))
                adminConnector = (ServerConnector) connector;
        }

        if (adminConnector == null) {
            List<String> adminListeners = config.adminListeners();
            if (adminListeners == null) {
                return advertisedUrl();
            } else if (adminListeners.isEmpty()) {
                return null;
            } else {
                log.error("No admin connector found for listeners {}", adminListeners);
                return null;
            }
        }

        UriBuilder builder = UriBuilder.fromUri(jettyServer.getURI());
        builder.port(adminConnector.getLocalPort());

        return builder.build();
    }
@return the admin url for this worker. Can be null if admin endpoints are disabled.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/rest/RestServer.java