# Package org.qi4j.spi.entitystore

EntityStore SPI.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  BackupRestore | Allow backups and restores of data in an EntityStore to be made
  EntityStateVersions | Entity versions state.
  EntityStore | Interface that must be implemented by store for persistent state of EntityComposites.
  EntityStoreSPI | EntityStore SPI.
  EntityStoreUnitOfWork | EntityStore UnitOfWork.
  StateChangeListener | Implement this interface in a Service if you want it to listen to changes from EntityStores.
  StateCommitter | After all EntityStore's have been prepared by `UnitOfWork.complete()`

- Class Summary
  Class | Description
  --- | ---
  ConcurrentModificationCheckConcern | Concern that helps EntityStores do concurrent modification checks.
  DefaultEntityStoreUnitOfWork | Default EntityStore UnitOfWork.
  EntityStateVersions.EntityStateVersionsMixin | Entity versions state mixin.
  ModuleEntityStoreUnitOfWork |
  StateChangeNotificationConcern | State change notification Concern.

- Exception Summary
  Exception | Description
  --- | ---
  ConcurrentEntityStateModificationException | This exception should be thrown if the EntityStore detects that the entities being saved have been changed since they were created.
  EntityAlreadyExistsException | This exception is thrown when an Entity already exists.
  EntityNotFoundException | This exception is thrown when an Entity could not be found.
  EntityStoreException | Base EntityStore Exception.
  ReadOnlyEntityStoreException | This exception is thrown for methods that creates or updates entities in read-only EntityStores.

## Package org.qi4j.spi.entitystore Description

## EntityStore SPI.