I am trying to develop custom source for parallel GCS content scanning. The naive approach would be to loop through listObjects function calls:
while (...) {
Objects objects = gcsUtil.listObjects(bucket, prefix, pageToken);
pageToken = objects.getNextPageToken();
...
}
The problem is performance for the tens of millions objects.
Instead of the single thread code we can add delimiter / and submit parallel processed for each prefix found:
...
Objects objects = gcsUtil.listObjects(bucket, prefix, pageToken, "/");
for (String subPrefix : object.getPrefixes()) {
scanAsync(bucket, subPrefix);
}
...
Next idea was to try to wrap this logic in Splittable DoFn.
Choice of RestrictionTracker: I don't see how can be used any of exiting RestrictionTracker. So decided to write own. Restriction itself is basically list of prefixes to scan. tryClaim checks if there is more prefixes left and receive newly scanned to append them to current restriction. trySplit splits list of prefixes.
The problem that I faced that trySplit can be called before all subPrefixes are found. In this case current restriction may receive more work to do after it was splitted. And it seems that trySplit is being called until it returns a not null value for a given RestrictionTracker: after certain number of elements goes to the output or after 1 second via scheduler or when ProcessContext.resume() returned. This doesn't work in my case as new prefixes can be found at any time. And I can't checkpoint via return ProcessContext.resume() because if split was already done, possible work that left in current restriction will cause checkDone() function to fail.
Another problem that I suspect that I couldn't achieve parallel execution in DirectRunner. As trySplit was always called with fractionOfRemainder=0 and new RestrictionTracker was started only after current one completed its piece of work.
It would be also great to read more detailed explanation about Splittable DoFn components lifecycle. How parallel execution per element is achieved. And how and when state of RestrictionTracker can be modified.
UPD: Adding simplified code that should show intended implementation
#DoFn.BoundedPerElement
private static class ScannerDoFn extends DoFn<String, String> {
private transient GcsUtil gcsUtil;
#GetInitialRestriction
public ScannerRestriction getInitialRestriction(#Element String bucket) {
return ScannerRestriction.init(bucket);
}
#ProcessElement
public ProcessContinuation processElement(
ProcessContext c,
#Element String bucket,
RestrictionTracker<ScannerRestriction, ScannerPosition> tracker,
OutputReceiver<String> outputReceiver) {
if (gcsUtil == null) {
gcsUtil = c.getPipelineOptions().as(GcsOptions.class).getGcsUtil();
}
ScannerRestriction currentRestriction = tracker.currentRestriction();
ScannerPosition position = new ScannerPosition();
while (true) {
if (tracker.tryClaim(position)) {
if (position.completedCurrent) {
// position.clear();
// ideally I would to get checkpoint here before starting new work
return ProcessContinuation.resume();
}
try {
Objects objects = gcsUtil.listObjects(
currentRestriction.bucket,
position.currentPrefix,
position.currentPageToken,
"/");
if (objects.getItems() != null) {
for (StorageObject o : objects.getItems()) {
outputReceiver.output(o.getName());
}
}
if (objects.getPrefixes() != null) {
position.newPrefixes.addAll(objects.getPrefixes());
}
position.currentPageToken = objects.getNextPageToken();
if (position.currentPageToken == null) {
position.completedCurrent = true;
}
} catch (Throwable throwable) {
logger.error("Error during scan", throwable);
}
} else {
return ProcessContinuation.stop();
}
}
}
#NewTracker
public RestrictionTracker<ScannerRestriction, ScannerPosition> restrictionTracker(#Restriction ScannerRestriction restriction) {
return new ScannerRestrictionTracker(restriction);
}
#GetRestrictionCoder
public Coder<ScannerRestriction> getRestrictionCoder() {
return ScannerRestriction.getCoder();
}
}
public static class ScannerPosition {
private String currentPrefix;
private String currentPageToken;
private final List<String> newPrefixes;
private boolean completedCurrent;
public ScannerPosition() {
this.currentPrefix = null;
this.currentPageToken = null;
this.newPrefixes = Lists.newArrayList();
this.completedCurrent = false;
}
public void clear() {
this.currentPageToken = null;
this.currentPrefix = null;
this.completedCurrent = false;
}
}
private static class ScannerRestriction {
private final String bucket;
private final LinkedList<String> prefixes;
private ScannerRestriction(String bucket) {
this.bucket = bucket;
this.prefixes = Lists.newLinkedList();
}
public static ScannerRestriction init(String bucket) {
ScannerRestriction res = new ScannerRestriction(bucket);
res.prefixes.add("");
return res;
}
public ScannerRestriction empty() {
return new ScannerRestriction(bucket);
}
public boolean isEmpty() {
return prefixes.isEmpty();
}
public static Coder<ScannerRestriction> getCoder() {
return ScannerRestrictionCoder.INSTANCE;
}
private static class ScannerRestrictionCoder extends AtomicCoder<ScannerRestriction> {
private static final ScannerRestrictionCoder INSTANCE = new ScannerRestrictionCoder();
private final static Coder<List<String>> listCoder = ListCoder.of(StringUtf8Coder.of());
#Override
public void encode(ScannerRestriction value, OutputStream outStream) throws IOException {
NullableCoder.of(StringUtf8Coder.of()).encode(value.bucket, outStream);
listCoder.encode(value.prefixes, outStream);
}
#Override
public ScannerRestriction decode(InputStream inStream) throws IOException {
String bucket = NullableCoder.of(StringUtf8Coder.of()).decode(inStream);
List<String> prefixes = listCoder.decode(inStream);
ScannerRestriction res = new ScannerRestriction(bucket);
res.prefixes.addAll(prefixes);
return res;
}
}
}
private static class ScannerRestrictionTracker extends RestrictionTracker<ScannerRestriction, ScannerPosition> {
private ScannerRestriction restriction;
private ScannerPosition lastPosition = null;
ScannerRestrictionTracker(ScannerRestriction restriction) {
this.restriction = restriction;
}
#Override
public boolean tryClaim(ScannerPosition position) {
restriction.prefixes.addAll(position.newPrefixes);
position.newPrefixes.clear();
if (position.completedCurrent) {
// completed work for current prefix
assert lastPosition != null && lastPosition.currentPrefix.equals(position.currentPrefix);
lastPosition = null;
return true; // return true but we would need to claim again if we need to get next prefix
} else if (lastPosition != null && lastPosition.currentPrefix.equals(position.currentPrefix)) {
// proceed work for current prefix
lastPosition = position;
return true;
}
// looking for next prefix
assert position.currentPrefix == null;
assert lastPosition == null;
if (restriction.isEmpty()) {
// no work to do
return false;
}
position.currentPrefix = restriction.prefixes.poll();
lastPosition = position;
return true;
}
#Override
public ScannerRestriction currentRestriction() {
return restriction;
}
#Override
public SplitResult<ScannerRestriction> trySplit(double fractionOfRemainder) {
if (lastPosition == null && restriction.isEmpty()) {
// no work at all
return null;
}
if (lastPosition != null && restriction.isEmpty()) {
// work at the moment only at currently scanned prefix
return SplitResult.of(restriction, restriction.empty());
}
int size = restriction.prefixes.size();
int newSize = new Double(Math.round(fractionOfRemainder * size)).intValue();
if (newSize == 0) {
ScannerRestriction residual = restriction;
restriction = restriction.empty();
return SplitResult.of(restriction, residual);
}
ScannerRestriction residual = restriction.empty();
for (int i=newSize; i<=size; i++) {
residual.prefixes.add(restriction.prefixes.removeLast());
}
return SplitResult.of(restriction, residual);
}
#Override
public void checkDone() throws IllegalStateException {
if (lastPosition != null) {
throw new IllegalStateException("Called checkDone on not completed job");
}
}
#Override
public IsBounded isBounded() {
return IsBounded.UNBOUNDED;
}
}
I found this description of implementing a Sentiment Analysis task with OpenNLP. In my case I am using the newest OPenNLP-version, i.e., version 1.8.0. In the following example, they use a Maximum Entropy Model. I am using the same input.txt (tweets.txt)
http://technobium.com/sentiment-analysis-using-opennlp-document-categorizer/
public class StartSentiment {
public static DoccatModel model = null;
public static String[] analyzedTexts = {"I hate Mondays!"/*, "Electricity outage, this is a nightmare"/*, "I love it"*/};
public static void main(String[] args) throws IOException {
// begin of sentiment analysis
trainModel();
for(int i=0; i<analyzedTexts.length;i++){
classifyNewText(analyzedTexts[i]);
}
}
private static String readFile(String pathname) throws IOException {
File file = new File(pathname);
StringBuilder fileContents = new StringBuilder((int)file.length());
Scanner scanner = new Scanner(file);
String lineSeparator = System.getProperty("line.separator");
try {
while(scanner.hasNextLine()) {
fileContents.append(scanner.nextLine() + lineSeparator);
}
return fileContents.toString();
} finally {
scanner.close();
}
}
public static void trainModel() {
MarkableFileInputStreamFactory dataIn = null;
try {
dataIn = new MarkableFileInputStreamFactory(
new File("bin/text.txt"));
ObjectStream<String> lineStream = null;
lineStream = new PlainTextByLineStream(dataIn, StandardCharsets.UTF_8);
ObjectStream<DocumentSample> sampleStream = new DocumentSampleStream(lineStream);
TrainingParameters tp = new TrainingParameters();
tp.put(TrainingParameters.CUTOFF_PARAM, "2");
tp.put(TrainingParameters.ITERATIONS_PARAM, "30");
DoccatFactory df = new DoccatFactory();
model = DocumentCategorizerME.train("en", sampleStream, tp, df);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (dataIn != null) {
try {
} catch (Exception e2) {
e2.printStackTrace();
}
}
}
}
public static void classifyNewText(String text){
DocumentCategorizerME myCategorizer = new DocumentCategorizerME(model);
double[] outcomes = myCategorizer.categorize(new String[]{text});
String category = myCategorizer.getBestCategory(outcomes);
if (category.equalsIgnoreCase("1")){
System.out.print("The text is positive");
} else {
System.out.print("The text is negative");
}
}
}
In my case no matter what input String I am using, I am only getting a positive estimation of the input string. Any idea what could be the reason?
Thanks
I'm relatively new to Codename One. I'm trying to read an URL and save the content on a String. I tried:
private String lectura = "";
private String escritura = "";
/*-------------------------------------------------------
* Methods
*-------------------------------------------------------
*/
public Bulbs(int i, char rtype){
type = rtype;
number = i;
status = readCNO(type, number);
}
public String giveStatus(){
status = readCNO(type, number);
return status;
}
public void turnBulbOn(){
writeCNO('B', number, 1);
}
public void turnBulbOff(){
writeCNO('B', number, 0);
}
public String readCNO(char type, int number){
ConnectionRequest r = new ConnectionRequest();
r.setUrl("http://192.168.1.3/arduino/R!" + type + "/" + Integer.toString(number));
r.setPost(false);
r.addResponseListener(new ActionListener()
{
public void actionPerformed(ActionEvent ev)
{
try
{
NetworkEvent event = (NetworkEvent) ev;
byte[] data= (byte[]) event.getMetaData();
String decodedData = new String(data,"UTF-8");
System.out.println(decodedData);
lectura = decodedData;
} catch (Exception ex)
{
ex.printStackTrace();
lectura = "NoBulb";
}
}
});
NetworkManager.getInstance().addToQueue(r);
return lectura;
}
public String writeCNO(char type, int number, int action){
ConnectionRequest r2 = new ConnectionRequest();
r2.setUrl("http://192.168.1.3/arduino/R!" + type + "/" + Integer.toString(number) + "/"+ action);
r2.setPost(false);
r2.addResponseListener(new ActionListener()
{
public void actionPerformed(ActionEvent ev)
{
try
{
NetworkEvent event = (NetworkEvent) ev;
byte[] data= (byte[]) event.getMetaData();
String decodedData = new String(data,"UTF-8");
System.out.println(decodedData);
escritura = decodedData;
} catch (Exception ex)
{
ex.printStackTrace();
escritura = "NoBulb";
}
}
});
NetworkManager.getInstance().addToQueue(r2);
return escritura;
}
However when I run it, the Console displays a bunch of errors like:
Duplicate entry in the queue: com.codename1.io.ConnectionRequest: com.codename1.io.ConnectionRequest#22b3c488
Help very appreciated!
David.
You are adding the exact same URL to the queue twice which Codename One detects as a probable mistake. If this is intentional just invoke setDuplicateSupported(true) on both connection requests.
I am trying to draw a list of all contacts saved in device. Everything is fine but when I select all contacts, I get only those contacts which are drawn on the screen. In other words, list drawing only those contacts which are visible on screen. To get the remaining contacts I have to scroll the list.
Here is my code:
public class CheckboxListField extends VerticalFieldManager implements ListFieldCallback, FieldChangeListener {
private static Vector selectedContacts ;
private ChecklistData[] mListData = new ChecklistData[] {};
private ListField mListField;
private static Vector mContacts;
private ContactList contactList;
private Enumeration allContacts;
private SendEmail sendEmail;
private boolean isChecked=false;
private BlackBerryContact contactItem;
private VerticalFieldManager _mainVFM = new VerticalFieldManager();
private int i;
private int j=0;
private String emails="";
private ButtonField _inviteButton;
private HorizontalFieldManager selectAllHFM;
private CustomButtonField selectAllButton;
private Bitmap _uncheckBmp;
private Bitmap _checkBmp;
private LabelField selectAllLabel;
private CheckboxField selectAllCheckBox;
private VerticalFieldManager contactListVFM;
private boolean listItemChecked=false;
private StringBuffer rowString;
private boolean getCBoxStatus;
// A class to hold the Strings in the CheckBox and it's checkbox state
// (checked or unchecked).
private class ChecklistData {
private String _stringVal;
private boolean _checked;
private String _telNumber;
ChecklistData(String stringVal, boolean checked) {
_stringVal = stringVal;
_checked = checked;
//_telNumber = telNumber;
}
// Get/set methods.
private String getStringVal() {
return _stringVal;
}
private boolean isChecked() {
return _checked;
}
// Toggle the checked status.
public void toggleChecked() {
_checked = !_checked;
}
}
public CheckboxListField() {
_mainVFM.add(createContactList(isChecked));
add(_mainVFM);
}
public VerticalFieldManager createContactList(boolean checked){
isChecked = checked;
selectedContacts = new Vector();
//INVITE BUTTON
contactListVFM = new VerticalFieldManager();
_inviteButton=new ButtonField("Invite Friend");
_inviteButton.setChangeListener(this);
_inviteButton.setMargin(2,0,10,0);
//SELECT ALL CHECKBOX
selectAllHFM = new HorizontalFieldManager();
_uncheckBmp = Bitmap.getBitmapResource("Uncheck.png");
_checkBmp = Bitmap.getBitmapResource("checked.png");
selectAllButton = new CustomButtonField(29, "", _uncheckBmp, _checkBmp, ButtonField.CONSUME_CLICK);
selectAllButton.setChangeListener(this);
selectAllButton.setMargin(5,5,5,5);
selectAllCheckBox = new CheckboxField("Select All", isChecked){
protected boolean navigationClick(int status,
int time) {
selectedContacts = new Vector();
emails = "";
boolean getCBoxStatus = selectAllCheckBox.getChecked();
if(listItemChecked == false){
if(_mainVFM.getFieldCount()!= 0){
_mainVFM.deleteAll();
_mainVFM.add(createContactList(getCBoxStatus));
}
}
return true;
}
};
selectAllCheckBox.setChangeListener(this);
selectAllLabel = new LabelField("Select All");
selectAllLabel.setMargin(5,5,5,5);
selectAllHFM.add(selectAllCheckBox);
//selectAllHFM.add(selectAllLabel);
// toggle list field item on navigation click
mListField = new ListField() {
protected boolean navigationClick(int status,
int time) {
toggleItem();
return true;
};
};
// set two line row height
//mListField.setRowHeight(getFont().getHeight() * 2);
mListField.setCallback(this);
//contactListVFM.add(new NullField(NullField.FOCUSABLE));
contactListVFM.add(_inviteButton);
contactListVFM.add(selectAllHFM);
contactListVFM.add(new SeparatorField());
contactListVFM.add(mListField);
//LOAD CONTACTS
// load contacts in separate thread
loadContacts.run();
return contactListVFM;
}
protected Runnable loadContacts = new Runnable() {
public void run() {
reloadContactList();
// fill list field control in UI event thread
UiApplication.getUiApplication().invokeLater(
fillList);
}
};
protected Runnable fillList = new Runnable() {
public void run() {
int size = mContacts.size();
mListData = new ChecklistData[size];
for (int i =0; i < mContacts.size() ; i++) {
contactItem = (BlackBerryContact) mContacts
.elementAt(i);
String displayName = getDisplayName(contactItem);
// String telContact = getContact(item);
mListData[i] = new ChecklistData(
displayName, isChecked);
mListField.invalidate(i);
System.out.println(">>>>>>>>>"+mListData[i]);
}
mListField.setSize(size);
//invalidate();
}
};
protected void toggleItem() {
listItemChecked = true ;
selectAllCheckBox.setChecked(false);
listItemChecked =false ;
// Get the index of the selected row.
int index = mListField.getSelectedIndex();
System.out.println("..............."+index);
if (index != -1) {
// Get the ChecklistData for this row.
ChecklistData data = mListData[index];
// Toggle its status.
data.toggleChecked();
mListField.invalidate(index);
}
}
private boolean reloadContactList() {
try {
contactList = (ContactList) PIM
.getInstance()
.openPIMList(PIM.CONTACT_LIST,
PIM.READ_ONLY);
allContacts = contactList.items();
mContacts = enumToVector(allContacts);
mListField.setSize(mContacts.size());
System.out.println(",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,>>>>>>>>>>"+mListField.getSize());
return true;
} catch (PIMException e) {
return false;
}
}
// Convert the list of contacts from an Enumeration to a Vector
private Vector enumToVector(Enumeration contactEnum) {
Vector v = new Vector();
if (contactEnum == null)
return v;
while (contactEnum.hasMoreElements()){
Contact contact = (Contact) allContacts.nextElement();
if(contactList.isSupportedField(Contact.EMAIL)&& (contact.countValues(Contact.EMAIL) > 0)) {
String emailID=contact.getString(Contact.EMAIL, 0);
if(emailID.length() !=0 && emailID != null ){
v.addElement(contact);
}
}
}
return v;
}
public void drawListRow(ListField list,
Graphics graphics, int index, int y, int w) {
rowString = new StringBuffer();
Object obj = this.get(list, index);
if (list.getSelectedIndex() != index) {
graphics.setBackgroundColor(index % 2 == 0 ||index==0 ? Color.WHITE
: Color.LIGHTGRAY);
graphics.clear();
//list.setFocus();
}
BlackBerryContact contact = (BlackBerryContact) mContacts
.elementAt(index);
String email= contact.getString(Contact.EMAIL, 0);
int vecIndex = selectedContacts.indexOf(email);
if (obj != null) {
ChecklistData currentRow = (ChecklistData) obj;
if (currentRow.isChecked()) {
if(vecIndex == -1){
selectedContacts.addElement(email);
}
rowString
.append(Characters.BALLOT_BOX_WITH_CHECK);
} else {
selectedContacts.removeElement(email);
rowString.append(Characters.BALLOT_BOX);
}
// Append a couple spaces and the row's text.
rowString.append(Characters.SPACE);
rowString.append(Characters.SPACE);
rowString.append(currentRow.getStringVal());
// Draw the text.
}
graphics.drawText(rowString.toString(), 0, y,
0, w);
}
public static String getDisplayName(Contact contact) {
if (contact == null) {
return null;
}
String displayName = null;
// First, see if there is a meaningful name set for the contact.
if (contact.countValues(Contact.NAME) > 0) {
final String[] name = contact.getStringArray(
Contact.NAME, 0);
final String firstName = name[Contact.NAME_GIVEN];
final String lastName = name[Contact.NAME_FAMILY];
if (firstName != null && lastName != null) {
displayName = firstName + " " + lastName;
} else if (firstName != null) {
displayName = firstName;
} else if (lastName != null) {
displayName = lastName;
}
if (displayName != null) {
final String namePrefix = name[Contact.NAME_PREFIX];
if (namePrefix != null) {
displayName = namePrefix + " "
+ displayName;
}
return displayName;
}
}
return displayName;
}
// Returns the object at the specified index.
public Object get(ListField list, int index) {
Object result = null;
if (mListData.length > index) {
result = mListData[index];
}
System.out.println(",,,,,,,,,,,,,,,,,,,,,,,"+mListData.length);
return result;
}
// Returns the first occurrence of the given String,
// beginning the search at index, and testing for
// equality using the equals method.
public int indexOfList(ListField list, String p, int s) {
return -1;
}
// Returns the screen width so the list uses the entire screen width.
public int getPreferredWidth(ListField list) {
return Graphics.getScreenWidth();
// return Display.getWidth();
}
public void fieldChanged(Field field, int context) {
if(field==_inviteButton){
for(int n=0 ; n<selectedContacts.size() ; n++){
emails= emails + selectedContacts.elementAt(n)+",";
}
//}
String mailBody =": "+Jxa.loginUserName+" invited you on NaijaPings app. Please download NaijaPings Android app from here "+"http://appworld.blackberry.com/webstore/content/77264/?lang=en" ;
sendEmail=new SendEmail(mailBody);
sendEmail.Email(emails,Constant.emailSubject);
emails ="" ;
selectedContacts.removeAllElements();
}else if(field == selectAllCheckBox){
selectedContacts = new Vector();
emails = "";
getCBoxStatus = selectAllCheckBox.getChecked();
//selectedContacts.removeAllElements();
if(listItemChecked == false){
if(_mainVFM.getFieldCount()!= 0){
_mainVFM.deleteAll();
_mainVFM.add(createContactList(getCBoxStatus));
}
}
}
}
}
Here ,in drawListRow() , get() method is called only that many times that is number of contacts are visible on the screen. For remaining contact to add, I have to scroll the list.
In drawListRow() method I am adding those contacts into selectedContacts vector and than using those vector to get contact to send a mail. Contacts will be added only when particular list item will be drawn.
So, how I can get all selected contact without scrolling the list?
This is similar to the problem you had in one of your other recent questions. The problem is that drawListRow() is a callback designed to let you draw the rows that need drawing. It's not meant to do anything else, like assembling a list of contacts to email.
The BlackBerry OS tries to be efficient, so it will only ask you to drawListRow() for the rows that are actually visible to the user (on screen). Anything more would be wasteful.
So, if you want to assemble a list of all selected rows, you should do it somewhere else, not in drawListRow().
It looks to me like you can build a list of all currently selected rows by using this code, wherever you want:
public Vector getSelectedContacts() {
selectedContacts.removeAllElements();
for (int i = 0; i < mListData.length; i++) {
Object obj = mListData[i];
if (obj != null) {
BlackBerryContact contact = (BlackBerryContact) mContacts.elementAt(i);
String email = contact.getString(Contact.EMAIL, 0);
int vecIndex = selectedContacts.indexOf(email);
ChecklistData currentRow = (ChecklistData) obj;
if (currentRow.isChecked()) {
if(vecIndex == -1){
selectedContacts.addElement(email);
}
} else {
// this line is probably not actually needed, since we
// call removeAllElements() at the start of this method
selectedContacts.removeElement(email);
}
}
}
return selectedContacts;
}
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?
If someone has experienced the same problem you can try to disconnect the device before wiping it. It is strange but it helped :)