public synchronized void clear() throws IOException {
initialize();
for (Iterator i = mapsContainer.getKeys().iterator(); i.hasNext();) {
ContainerId id = (ContainerId)i.next();
MapContainer container = getMapContainer(id.getKey(), id.getDataContainerName());
container.clear();
}
for (Iterator i = listsContainer.getKeys().iterator(); i.hasNext();) {
ContainerId id = (ContainerId)i.next();
ListContainer container = getListContainer(id.getKey(), id.getDataContainerName());
container.clear();