Develop Reference

List all files, recursively, in Android Dropbox API

How can I list all files, recursively in DropBox folder?
I tried code below but returns no result:
result = dbxClient.files().search("", "*");
And this returns files in path, not subfolders:
result = dbxClient.files().listFolder(path);

You can get a ListFolderBuilder from listFolderBuilder and use the withRecursive option to list out sub-items as well.
Be sure to check ListFolderResult.hasMore to see if you should call back to listFolderContinue to get more results though.

You can check this link, navigate to inner class 'FolderScanTask'. It contains working code for Android:
https://github.com/ControlX/Android-Dropbox-UploadImage-To-SpecificFolder-By-FolderSelection/blob/master/app/src/main/java/io/github/controlx/dbxdemo/MainActivity.java
This is work in progress, here I'm just making an ArrayList for parent folders, has more logic as suggested by Greg is already there you just need to fill in that.
Code Snippet for the same:
String path = "";
DbxClientV2 dbxClient = DropboxClient.getClient(ACCESS_TOKEN);
TreeMap<String, Metadata> children = new TreeMap<String, Metadata>();
try {
try {
result = dbxClient.files()
.listFolder(path);
} catch (ListFolderErrorException ex) {
ex.printStackTrace();
}
List<Metadata> list = result.getEntries();
cs = new CharSequence[list.size()];
arrayList = new ArrayList<>();
arrayList.add("/");
while (true) {
int i = 0;
for (Metadata md : result.getEntries()) {
if (md instanceof DeletedMetadata) {
children.remove(md.getPathLower());
} else {
String fileOrFolder = md.getPathLower();
children.put(fileOrFolder, md);
if(!fileOrFolder.contains("."))
arrayList.add(fileOrFolder);
}
i++;
}
if (!result.getHasMore()) break;
try {
result = dbxClient.files()
.listFolderContinue(result.getCursor());
} catch (ListFolderContinueErrorException ex) {
ex.printStackTrace();
}
}
} catch (DbxException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
Here ArrayList is just for my use wherein I'm just making a list of only folders.
So, modify accordingly.

android file system persistance

Hi Iam having serious issues try to persist some serializable objects to a file on the local android file system. Iam getting a Bad file descriptor error and I think it is to do with my methods for creating the file. the file and checking if the file exists. i create a private file object in the class. Then, on write or read. I check file existance with the following code.
#Override
public boolean fileExists() {
File file = context.getFileStreamPath(filename);
return file.exists();
}
this doesnt instantiate my file object called "objectfile"!! but does check the "filename" exists.
to create the file I call this method if "filename" doesnt exist.
public void createFile()
{
objectfile = new File(context.getFilesDir(), filename);
objectfile.setReadable(true);
objectfile.setWritable(true);
}
Iam not sure if this will give me back my previously created file which would be ideally what I want to do. Is there a way i can just get the old file or create a new one and pass it to "objectfile" variable in the constructor??
Iam also wondering what the best way to do this is??
Or should i just use the mysqlite db? using object file persistance doesn't seem to be working out for me right now and iam working to a deadline. Also this method is mention in the gooogle docs so I thought it would be legit was to do it.
http://developer.android.com/training/basics/data-storage/files.html
here is my method for reading the serializable objects
public synchronized ArrayList<RoomItem> readObjects() {
final ArrayList<RoomItem> readlist = new ArrayList<>();
if(!fileExists())
return readlist;
if(objectfile == null)
createFile();
try {
finputstream = new FileInputStream(objectfile);
instream = new ObjectInputStream(finputstream);
readwritethread = new Thread(new Runnable() {
#Override
public void run() {
try {
final ArrayList<RoomItem> readitems = (ArrayList<RoomItem>) instream.readObject();
instream.close();
finputstream.close();
handler.post(new Runnable() {
#Override
public void run() {
listener.updateList(readitems);
}
});
} catch(IOException e)
{
e.printStackTrace();
}
catch(ClassNotFoundException e)
{
e.printStackTrace();
Log.d("read failed", "file read failed");
}
}
});
}
catch(Exception e)
{
e.printStackTrace();
}
timeOutReadWrite(readwritethread);
readwritethread.start();
try {
readwritethread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.d("read from file", "file read");
return readlist;
if anyone could suggest any improvements id really appreciate it. I use a handler to pass back to my activity and implement a listener interface on my activity thats call the activity when all the obj are read. Thanks again!

1#: Yes, it will return the original file you created.
2#: Depends on the thing you want to store, seems File is more flex from description
hope helpful.

We have used
FileOutputStream fos = context.openFileOutput("file.ser", Context.MODE_PRIVATE);
to write our serialized files.This will carete files in /data/data/app.package.name/files/. In fact, this path is returned by getFilesDir().
And while deserializing, use
//make sure you pass the same file that was passed to openFileOutput()..
FileInputStream fis = context.openFileInput("file.ser");
Also, to avoid confusing between file names you can use name of class that is being serialized.
Ex:
public static <T> void serialize(final Context context, final T objectToSerialize) {
....
....
Strin fileName = objectToSerialize.getClass().getSimpleName();
...
}
Do this and keep the method in util so it can be used for any type of objects (T type) to serialize.

Put objects into bundle

Greetings,
I have a game, and i want to save the objects ( creatues ) that move on canvas to a bundle so that when someone pauses/leaves the app, the objects can stay where they were.
I have looked at the LunarLanding game where they save the coordinates of the space shuttle into bundles and read from them and i want to do same ( if there is no better way ) but i have objects of a custom type and i am not sure how to save them and read from the bundle.
I could do the save of all the parts of the object individually and put them back together, but i have a lot of objects and that would just be ugly code to do all that.
It would be just great if i could save an object to a bundle, but so far i had no luck searching the internet on how to do so.
I was also thinking about implementing Parcelable to my object, but i want to know if there is any other way.
Any suggestions?
Thanks!

Basically you have 2 options
1 - Implement Serializable, really simple to implement, but has a bad drawback which is performance.
2 - Implement Parcelable, very fast, but you need to implement the parser method (writeToParcel()), which basically you have to serialize manually, but afterwards bundle will call it automatically for you and will produce a much more performatic serialization.

Technically, the onSaveInstanceState() method is called mostly only on orientation change if I remember correctly. If you want to make persistent data, you should use the onPause() or onStop() callback, and serialize the game state.
The ways you can do that is either by storing the state in a SQLite database (seems overkill), or make it so that you can serialize the object that keeps track of the entities via implementing the Serializable interface, and save the object to a file.
Serialization:
#Override
public void onPause()
{
super.onPause();
FileOutputStream out = null;
try
{
out = openFileOutput("GameModelBackup",Context.MODE_PRIVATE);
try
{
ObjectOutputStream oos = new ObjectOutputStream(out);
oos.writeObject(gm);
}
catch(IOException e)
{
Log.d(this.getClass().toString(), e.getMessage());
}
}
catch(FileNotFoundException e)
{
Log.d(this.getClass().toString(), e.getMessage());
}
finally
{
try
{
if(out != null) out.close();
}
catch(IOException e)
{
Log.d(this.getClass().toString(), e.getMessage());
}
}
}
Deserialization:
#Override
public void onResume()
{
super.onResume();
FileInputStream in = null;
try
{
in = openFileInput("GameModelBackup");
ObjectInputStream oos = new ObjectInputStream(in);
try
{
gm = (GameModel)oos.readObject();
}
catch(ClassNotFoundException e)
{
gm = null;
}
}
catch(IOException e)
{
Log.d(this.getClass().toString(), e.getMessage());
}
finally
{
try
{
if(in != null) in.close();
}
catch(IOException e) {}
}
}

How to insert bulk data in android sqlite database using ormlite efficiently

I'm trying to insert 100000 records in android sqlite database at a time. I'm using following two different methods.
private void bulkInsertDataBySavePoint(final List<User> users) {
log.debug("bulkInsertDataBySavePoint()");
DatabaseConnection conn = null;
Savepoint savepoint = null;
try {
conn = userDao.startThreadConnection();
savepoint = conn.setSavePoint("bulk_insert");
for (User user : users) {
userDao.create(user);
}
} catch (SQLException e) {
log.error("Something went wrong in bulk Insert", e);
} finally {
if (conn != null) {
try {
conn.commit(savepoint);
userDao.endThreadConnection(conn);
} catch (SQLException e) {
log.error("Something went wrong in bulk Insert", e);
}
}
}
}
And
private void bulkInsertDataByCallBatchTasks(final List<User> users) {
log.debug("bulkInsertDataByCallBatchTasks()");
try {
userDao.callBatchTasks(new Callable<Void>() {
#Override
public Void call() throws Exception {
for (User user : users) {
userDao.create(user);
}
return null;
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
Both methods work fine. On average they take 140 seconds and take 60-65% CPU which is not ok, I think.
The idea is, I have to consume an api which will provide json data. I have to parse that json data and then insert into sqlite database for offline usage.
I'm looking for an efficient way to solve this issue.
Any thought?

I'm trying to insert 100000 records in android sqlite database at a time... On average they take 140 seconds and take 60-65% CPU which is not ok in my opinion.
Unfortunately I don't have an easy answer for you. You may have to do this sort of insert directly using raw SQL to achieve faster performance on the limited Android CPU. Once you have the data inserted then you can turn to ORMLite to query or manipulate the data faster.

I've had the same problem, and found a reasonable workaround. This took insert time from 2 seconds to 150ms:
final OrmLiteSqliteOpenHelper myDbHelper = ...;
final SQLiteDatabase db = myDbHelper.getWritableDatabase();
db.beginTransaction();
try{
// do ormlite stuff as usual, no callBatchTasks() needed
db.setTransactionSuccessful();
}
finally {
db.endTransaction();
}

Hrm. Good idea #FarrukhNajmi. I've just added it to trunk. It will be in version 4.49.
#Gray Is it still unstable? when can we see it in maven?
And if com.j256.ormlite.dao.ForeignCollection#addAll make only one request it would be nice too.

Ormlite ObjectCache returning old data

I'm using Ormlite on Android and with the ObjectCache enabled, I get old data back after updating the table with an UpdateBuilder and a ColumnExpression. I have read through the doc and it does not warn against using the UpdateBuilder with the cache enabled.
The settings table should have just 1-5ish rows max. The updateColumnExpression seems like an easy way to allow only one of the rows to be true.
Is this the expected behavior?
public void setActiveSetting(String id)
{
try {
UpdateBuilder<Settings, Integer> updateBuilder2 = getHelper().getSettingsDao().updateBuilder();
updateBuilder2.updateColumnExpression("active", "id = " + id );
updateBuilder2.update();
} catch (SQLException e){
e.printStackTrace();
}
}
And this is the call that returns the outdated data:
public List<Settings> getSettings()
{
List<Settings> settings = null;
try {
settings = getHelper().getSettingsDao().queryForAll();
} catch (SQLException e) {
e.printStackTrace();
}
return settings;
}
And the settings DAO:
public Dao<Settings, Integer> getSettingsDao()
{
if (null == settingsDao) {
try {
settingsDao = getDao(Settings.class);
settingsDao.setObjectCache(true);
} catch (java.sql.SQLException e) {
e.printStackTrace();
}
}
return settingsDao;
}
Disabling the ObjectCache does return the correct data, but this data is fetched quite frequently, so I'd like to keep it.
Thanks

Is this the expected behavior?
Unfortunately, yes. If you had updated the object using dao.update(...); then the cache would know that the object needed to be refreshed. By using the UpdateBuilder to make mass changes to the table, there is no way for the cache to know which objects were affected.
You will need to clear the cache after your call to the UpdateBuilder finishes.