com.db4o.ext
Interface ExtClient
- All Superinterfaces:
- ExtObjectContainer, ObjectContainer
- public interface ExtClient
- extends ExtObjectContainer
extended client functionality for the
ExtObjectContainer
interface.
Both
Db4o.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.
Method Summary |
void |
switchToFile(java.lang.String fileName)
requests opening a different server database file for this client session.
|
void |
switchToMainFile()
requests switching back to the main database file after a previous call
to switchToFile(String fileName) .
|
Methods inherited from interface com.db4o.ext.ExtObjectContainer |
bind, configure, getByID, getID, isActive, isCached, isClosed, isStored, purge, purge, storedClass, storedClasses |
switchToFile
public void switchToFile(java.lang.String fileName)
- requests opening a different server database file for this client session.
This method can be used to switch between database files from the client
side while not having to open a new socket connection or closing the
current one.
If the database file does not exist on the server, it will be created.
A typical usecase:
The main database file is used for login, user and rights management only.
Only one single db4o server session needs to be run. Multiple satellite
database files are used for different applications or multiple user circles.
Storing the data to multiple database files has the following advantages:
- easier rights management
- easier backup
- possible later load balancing to multiple servers
- better performance of smaller individual database files
- special debugging database files can be used
User authorization to the alternative database file will not be checked.
All persistent references to objects that are currently in memory
are discarded during the switching process.
- Parameters:
fileName
- the fully qualified path of the requested database file.
switchToMainFile
public void switchToMainFile()
- requests switching back to the main database file after a previous call
to
switchToFile(String fileName)
.
All persistent references to objects that are currently in memory
are discarded during the switching process.