/** The key of the configuration. e.g. fess_config */
    String INDEX_CONFIG_INDEX = "index.config.index";

    /** The key of the configuration. e.g. fess_user */
    String INDEX_USER_INDEX = "index.user.index";

    /** The key of the configuration. e.g. fess_log */
    String INDEX_LOG_INDEX = "index.log.index";