<xml> </xml>

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.