com.db4o.ext

db4o |

# com.db4o.ext Namespace

Advanced API package.

Namespace hierarchy

### Classes

Class | Description
--- | ---
DatabaseFileLockedException | this Exception is thrown during any of the db4o open calls if the database file is locked by another process.
Db4oUUID | a unique universal identify for an object.
ExtDb4o | extended factory class with static methods to open special db4o sessions.
MemoryFile | carries in-memory data for db4o in-memory operation.
ObjectNotStorableException | this Exception is thrown, if objects can not be stored and if db4o is configured to throw Exceptions on storage failures.
Status | Static constants to describe the status of objects.

### Interfaces

Interface | Description
--- | ---
Db4oCallback | generic callback interface.
ExtClient | extended client functionality for the ExtObjectContainer interface. Both openClient methods always return an
    ExtClient
object so a cast is possible. The ObjectContainer functionality is split into multiple interfaces to allow newcomers to focus on the essential methods.
ExtObjectContainer | extended functionality for the ObjectContainer interface. Every db4o ObjectContainer always is an
    ExtObjectContainer
so a cast is possible. com.db4o.ObjectContainer.ext is a convenient method to perform the cast. The ObjectContainer functionality is split to two interfaces to allow newcomers to focus on the essential methods.
ExtObjectServer | extended functionality for the ObjectServer interface.
ExtObjectSet | extended functionality for the ObjectSet interface. Every db4o ObjectSet always is an ExtObjectSet so a cast is possible. com.db4o.ObjectSet.ext is a convenient method to perform the cast. The ObjectSet functionality is split to two interfaces to allow newcomers to focus on the essential methods.
ObjectCallbacks | callback methods.
ObjectInfo | interface to the internal reference that an ObjectContainer holds for a stored object.
StoredClass | the internal representation of a stored class.
StoredField | the internal representation of a field on a stored class.