Backup/Restore net.rim.device.api.util.Persitable object with DesktopManger - blackberry

Question

The task is to backup/restore Persistable object with BB Desktop Manager or in any other way. The main aim is to keep data between device firmware updates...
I have:
public final class UserList implements Persistable {
//The persistable objects.
private Hashtable fData;
//Initialize the class with empty values.
public UserList() {
fData = new Hashtable();
}
//Initialize the class with the specified values.
public UserList(Hashtable p) {
fData = p;
}
public Hashtable getData() {
return fData;
}}
I also have implemented SyncItem (as found in one of the examples)
public final class UserListSync extends SyncItem {
private static UserList fList;
private static final int FIELDTAG_NAME = 1;
private static final int FIELDTAG_AGE = 2;
private static PersistentObject store;
static {
store = PersistentStore.getPersistentObject(0x3167239af4aa40fL);
}
public UserListSync() {
}
public String getSyncName() {
return "Sync Item Sample";
}
public String getSyncName(Locale locale) {
return null;
}
public int getSyncVersion() {
return 1;
}
public boolean getSyncData(DataBuffer db, int version) {
boolean retVal = true;
synchronized (store) {
if (store.getContents() != null) {
fList = (UserList)store.getContents();
}
}
try {
Enumeration e = fList.getData().keys();
while (e.hasMoreElements()) {
String key = (String) e.nextElement();
String value = (String) fList.getData().get(key);
//Write the name.
db.writeShort(key.length() + 1);
db.writeByte(FIELDTAG_NAME);
db.write(key.getBytes());
db.writeByte(0);
//Write the age.
db.writeShort(value.length() + 1);
db.writeByte(FIELDTAG_AGE);
db.write(value.getBytes());
db.writeByte(0);
}
} catch (Exception e) {
retVal = false;
}
return retVal;
}
//Interprets and stores the data sent from the Desktop Manager.
public boolean setSyncData(DataBuffer db, int version) {
int length;
Hashtable table = new Hashtable();
Vector keys = new Vector();
Vector values = new Vector();
boolean retVal = true;
try {
//Read until the end of the Databuffer.
while (db.available() > 0) {
//Read the length of the data.
length = db.readShort();
//Set the byte array to the length of the data.
byte[] bytes = new byte[length];
//Determine the type of data to be read (name or age).
switch (db.readByte()) {
case FIELDTAG_NAME:
db.readFully(bytes);
keys.addElement(new String(bytes).trim());
break;
case FIELDTAG_AGE:
db.readFully(bytes);
values.addElement(new String(bytes).trim());
break;
}
}
} catch (Exception e) {
retVal = false;
}
for (int i = 0; i < keys.size(); i++) {
table.put(keys.elementAt(i), values.elementAt(i));
}
try {
//Store the new data in the persistent store object.
fList = new UserList(table);
store.setContents(fList);
store.commit();
} catch (Exception e) {
retVal = false;
}
return retVal;
}}
The entry poing is following:
public class SyncItemSample extends UiApplication {
private static PersistentObject store;
private static UserList userList;
static {
store = PersistentStore.getPersistentObject(0x3167239af4aa40fL);
}
public static void main(String[] args) {
SyncItemSample app = new SyncItemSample();
app.enterEventDispatcher();
}
public SyncItemSample() {
UserListScreen userListScreen;
//Check to see if the store exists on the BlackBerry.
synchronized (store) {
if (store.getContents() == null) {
//Store does not exist, create it with default values
userList = new UserList();
store.setContents(userList);
store.commit();
} else {
//Store exists, retrieve data from store.
userList = (UserList)store.getContents();
}
}
//Create and push the UserListScreen.
userListScreen = new UserListScreen(userList);
pushScreen(userListScreen);
}}
And here is an implementation of screen:
public final class UserListScreen extends MainScreen {
Vector fLabels = new Vector();
Vector fValues = new Vector();
VerticalFieldManager leftColumn = new VerticalFieldManager();
VerticalFieldManager rightColumn = new VerticalFieldManager();
UserList fList;
public UserListScreen(UserList list) {
super();
fList = list;
//Create a horizontal field manager to hold the two vertical field
//managers to display the names and ages in two columns.
VerticalFieldManager inputManager = new VerticalFieldManager();
HorizontalFieldManager backGround = new HorizontalFieldManager();
//Array of fields to display the names and ages.
LabelField title = new LabelField("User List",
LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
setTitle(title);
final TextField fld1 = new TextField(TextField.NO_NEWLINE);
fld1.setLabel("input label");
inputManager.add(fld1);
final TextField fld2 = new TextField(TextField.NO_NEWLINE);
fld2.setLabel("input value");
inputManager.add(fld2);
final ButtonField fld3 = new ButtonField();
fld3.setChangeListener(new FieldChangeListener() {
public void fieldChanged(Field field, int context) {
fList.getData().put(fld1.getText().trim(), fld2.getText().trim());
refresh();
}
});
fld3.setLabel("add");
inputManager.add(fld3);
add(inputManager);
//Add the column titles and a blank field to create a space.
LabelField leftTitle = new LabelField("label ");
leftColumn.add(leftTitle);
LabelField rightTitle = new LabelField("value");
rightColumn.add(rightTitle);
refresh();
//Add the two vertical columns to the horizontal field manager.
backGround.add(leftColumn);
backGround.add(rightColumn);
//Add the horizontal field manager to the screen.
add(backGround);
}
private void refresh() {
leftColumn.deleteAll();
rightColumn.deleteAll();
fLabels.removeAllElements();
fValues.removeAllElements();
//Populate and add the name and age fields.
Enumeration e = fList.getData().keys();
while (e.hasMoreElements()) {
String key = (String) e.nextElement();
String value = (String) fList.getData().get(key);
final LabelField tmp1 = new LabelField(key);
final LabelField tmp2 = new LabelField(value);
leftColumn.add(tmp1);
rightColumn.add(tmp2);
fLabels.addElement(tmp1);
fValues.addElement(tmp2);
}
}
public boolean onClose() {
System.exit(0);
return true;
}}
So as you see it should be very easy...
So all of these I run application, add values to Persistent object and they are added correctly, are stored during device resets and so on...
When I run Desktop Manager and make a Backup it seems that UserList is backed-up, as size of backup grows together with adding new data into persistent store.
But when I run "Wipe device" on my BB 9300 (and all data from Persistent store is cleared as it is expected) and then run Restore from just made backup file - nothing is updated in the Application and persistent store is seems to be empty.
In some examples I have found adding alternate entry point "init" but I can't tune eveything like it is described with my EclipsePlugin
Could you advice me how to store data in backup file and the to retrieve the same data from backup and load it back to the application, or how to log any of events with Desktop Manager?

Answer 1

If someone has experienced the same problem you can try to disconnect the device before wiping it. It is strange but it helped :)