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任務是備份/恢復持久化對象與BB Desktop Manager或以任何其他方式。主要目的是爲了保持設備的固件更新之間的數據...備份/恢復net.rim.device.api.util.Persitable對象與DesktopManger
我：
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;
}}
我也已經實現SyncItem
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;
}}
的（如在一個例子中）進入Poing的是以下幾點：
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);
}}
這裏是屏幕的實現：
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;
}}
所以你看它應該是很容易的......
因此，所有這些我運行應用程序，添加值持久化對象和他們正確添加，在設備復位等存儲... 當我運行桌面管理器，並使其似乎UserList的是備份，備份的大小與添加新數據持久性存儲一起成長備份。
但是，當我在我的BB 9300上運行「擦除設備」（並且永久存儲的所有數據已按預期清除），然後從剛建立的備份文件運行恢復 - 應用程序和持久存儲中沒有更新似乎是空的。
在一些例子中，我發現加入備選入口點「初始化」但我不能像它調eveything與我EclipsePlugin描述
你能指點我如何將數據存儲在備份文件和檢索來自備份的相同數據並將其加載迴應用程序，或者如何使用Desktop Manager記錄任何事件？