public void deleteByAppId(Long appId){
  List<Config> configs=configDao.listByAppId(appId,0,0);
  if (configs != null && !configs.isEmpty()) {
    for (    Config config : configs) {
      delete(config);
    }
  }
}

public void deleteByAppId ( Long appId ) { List < Config > configs = configDao . listByAppId ( appId , 0 , 0 ) ; if ( configs != null && ! configs . isEmpty ( ) ) { for ( Config config : configs ) { delete ( config ) ; } } }
delete the config of the app
