- oldState
- An open, read-only ParcelFileDescriptor pointing to the last backup state provided by the application. May be null, in which case no prior state is being provided and the application should perform a full backup.
- data
- A structured wrapper around an open, read/write file descriptor pointing to the backup data destination. Typically the application will use backup helper classes to write to this file.
- newState
- An open, read/write ParcelFileDescriptor pointing to an empty file. The application should record the final backup state here after writing the requested data to the data output stream.
Type Reason Java.IO.IOException
Run the backup process on each of the configured handlers.