@Override
            public void notify(MetaStoreEventListener listener,
                               ListenerEvent event) throws MetaException {
              listener.onCreateDatabase((CreateDatabaseEvent)event);
            }
This class is used to notify a list of listeners about specific MetaStore events.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetaStoreListenerNotifier.java