Background
There are three ways to store application data on
BlackBerry smartphones:
Note: For detailed instructions on how to use the two storage models,
please see the “Storing persistent data” section in the BlackBerry
Java Development Environment Version 4.0: BlackBerry Application
Developer Guide. This guide covers all programmatic
saving, retrieving, and deletion of persistent data. However, it
does not discuss what happens to persistent data upon removal of
an application.
An application can be removed by using either the Application
Loader in BlackBerry® Desktop Manager or by accessing the list of
Applications on the BlackBerry smartphone.
If you use BlackBerry® Device Software 4.0 perform the following:
- On the Home screen, click Options > Applications.
- Select the application to delete, click the trackwheel,
and select Delete.
If you use BlackBerry Device Software 4.1 or later:
- On the Home screen, click Options > Advanced
Options > Applications.
- Select the application to delete, click the trackwheel
or trackball, and select Delete.
MIDP record stores
If you store the application data using MIDP record stores
on BlackBerry smartphones with BlackBerry Device Software earlier
than version 4.1, the application data is not deleted when the application
is removed. If removing this data is absolutely crucial, complete
the following:
Note: The following will impact more than just the desired application
- it will wipe all Record Management System (RMS) databases on the
BlackBerry smartphone.
- Connect the BlackBerry smartphone to BlackBerry
Desktop Manager.
- In BlackBerry Desktop Manager, open Backup and Restore and
click Advanced.
- Click RMS database > Clear.
If the BlackBerry smartphone is using BlackBerry Device Software
4.1, the application data is always deleted once the application
is removed.
Since MIDP record stores can only be accessed by the application
that owns them (there is no data sharing), you do not need to keep
the data once the application is removed. The only exception to
this rule is if the application is being replaced as part of an
upgrade using the Application Loader tool, a wireless download,
or the application is pushed out from the BlackBerry® Enterprise
Server.
Note: When upgrading, all data remains. The BlackBerry persistence model
When you use the BlackBerry persistence model, data is only
deleted if the store contains data that belongs to the removed application.
For example, if an application stores an object with a package
called com.mycompany.application.storage and no other
application on the BlackBerry smartphone makes reference to the
package, the persistent store and the removed application are deleted.
The same is true if the object is wrapped in a container such
as a Vector. Even if only one of the elements of the Vector has
a package name that is not used by other applications, the entire
Vector is removed from the persistent store.
Note: If the application does not store any objects with an identifying
package structure, (for example, an application that stores java.util.Vector or javax.microedition.location.AddressInfo objects),
the application should create and use a class that extends Vector in
order to identify that Vector belongs
to the given application. When you store this Vector,
which is identified uniquely by its package, you guarantee that
the data is removed from the persistent store when the application
is removed.
The BlackBerry file store (FileConnection)
Data stored by applications using a FileConnection is not
removed when an application is uninstalled. |