public static String getReadUrl() {
        String readUrl = XianConfig.get(READONLY_DB_URL);
        LOG.info("readonly_db_url = " + readUrl);
        return readUrl;
    }
public static String getReadUrl ( ) { String readUrl = XianConfig . get ( READONLY_DB_URL ) ; LOG . info ( "readonly_db_url = " + readUrl ) ; return readUrl ; }
read slave datasource configuration from xian config.
please refer to {@link XianDataSource#url}  to see database configuration format

@return datasource configuration url