bmgr lets you control the backup/restore system on an Android device.
bmgr is a shell tool you can use to interact with the Backup Manager
on Android devices supporting API Level 8 or greater. It provides commands to induce backup
and restore operations so that you don't need to repeatedly wipe data or take similar
intrusive steps in order to test your application's backup agent. These commands are
accessed via the adb shell.
For information about adding support for backup in your application, read Data Backup, which includes a guide to testing
your application using bmgr.
Normally, your application must notify the Backup Manager when its data has changed, via dataChanged(). The Backup Manager will then invoke your
backup agent's onBackup() implementation at some time in the future. However, instead of calling dataChanged(), you can invoke a backup request from the command
line by running the bmgr backup command:
adb shell bmgr backup <package>
<package> is the formal package name of the application you wish to
schedule for
backup. When you execute this backup command, your application's backup agent will be invoked to
perform a backup operation at some time in the future (via your onBackup() method), though there is no guarantee when it will occur. However, you can force all
pending backup operations to run immediately by using the bmgr run command:
adb shell bmgr run
This causes a backup pass to execute immediately, invoking the backup agents of all applications
that had previously called dataChanged() since the
last backup operation, plus any applications which had been manually scheduled for
backup via bmgr backup.
Unlike backup operations, which are batched together and run on an occasional basis, restore
operations execute immediately. The Backup Manager currently provides two kinds of restore
operations. The first kind restores an entire device with the data that has been backed up. This
is typically performed only when a device is first provisioned (to replicate settings and other
saved state from the user's previous device) and is an operation that only the system can
perform. The second kind of restore operation restores
a single application to its "active" data set; that is, the application will abandon its current
data and revert to the last-known-good data that is held in the current backup image. You can
invoke this second restore operation with the requestRestore() method. The
Backup Manager will then invoke your backup agent's onRestore() implementation.
While testing your application, you can immediately invoke the restore operation (bypassing the
requestRestore() method)
for your application by using the bmgr restore command:
adb shell bmgr restore <package>
<package> is the formal Java-style package name of the application
participating in the backup/restore mechanism, which you would like to restore. The Backup
Manager will immediately instantiate the application's backup agent and invoke it for restore. This
will happen even if your application is not currently running.
The data for a single application can be erased from the active data set on demand. This is
very useful while you're developing a backup agent, in case bugs lead you to write corrupt data
or saved state information. You can wipe an application's data with the bmgr wipe
command:
adb shell bmgr wipe <package>
<package> is the formal package name of the application whose data
you wish to
erase. The next backup operation that the application's agent processes will look as
though the application had never backed anything up before.
You can see whether the Backup Manager is operational at all with the bmgr
enabled command:
adb shell bmgr enabled
This might be useful if your application's backup agent is never being invoked for backup, to verify whether the operating system thinks it should be performing such operations at all.
You can also directly disable or enable the Backup Manager with this command:
adb shell bmgr enable <boolean>
<boolean> is either true or false.
This is equivalent to disabling or enabling backup in the device's main Settings UI.
Warning! When backup is disabled, the current backup transport
will explicitly wipe
the entire active data set from its backend storage. This is so that when a user says
they do not want their data backed up, the Backup Manager respects that wish. No further
data will be saved from the device, and no restore operations will be possible, unless the Backup
Manager is re-enabled (either through Settings or through the above bmgr command).
