Develop Reference

Why is my ContentResolver batch operation only putting in 7 out of 21 entries?

I have three fragments in a FragmentPagerAdapter, and each of them would fetch a list of frames/data from a server using Volley. This data would later be used to update the Fragment's RecyclerView Adapter as a Cursor.
VolleyRestClientUtils.get(getString(R.string.PATH_SHOP), LOG_TAG, params, true, false, new JsonHttpResponseHandler() {
public void onSuccess(JSONObject response) {
Log.d(LOG_TAG, "request Response : " + response.toString());
try {
String status = response.getString("status");
if (RestClientUtils.STATUS_OK.equals(status)) {
final JSONArray frames = response.getJSONArray("items");
Log.d(LOG_TAG, "request Response : " + frames.length());
if (frames != null && frames.length() > 0) {
new AsyncTask<Void, Void, Boolean>() {
#Override
protected Boolean doInBackground(Void... voids) {
List<ContentValues> listShopFrame = ShopFrame.fromJSONArray(frames, sort);
if (listShopFrame.size() > 0 && isActivityActive()) {
ContentResolver cr = getActivity().getContentResolver();
if (!isRequestMore) {
cr.delete(ShopFrame.CONTENT_URI, ShopFrame.COLUMN_CATEGORY + "=?",
new String[]{sort});
paramSkip = frames.length();
} else {
paramSkip += frames.length();
}
ArrayList<ContentProviderOperation> operations = new ArrayList<>();
String log = listShopFrame.size()+" ";
for (int i = 0; i < listShopFrame.size(); i++) {
operations.add(ContentProviderOperation
.newInsert(ShopFrame.CONTENT_URI)
.withValues(listShopFrame.get(i))
.build());
log += listShopFrame.get(i).toString()+"\n";
}
Log.i("loader_callback_"+sort, log);
//cr.applyBatch(ShopFrame.CONTENT_AUTHORITY, operations);
ContentValues[] opsAsArray = new ContentValues[listShopFrame.size()];
listShopFrame.toArray(opsAsArray);
cr.bulkInsert(ShopFrame.CONTENT_URI, opsAsArray);
//return true;
}
return true;
}
#Override
protected void onPostExecute(Boolean result) {
dataRefreshed = true;
Log.i("loader_callback_"+sort, "response post execute");
if (result) {
loadSucceed();
PicMixApp.getInstance().setRefreshed(ShopFrameFragment.this.getClass().getName());
} else {
loadFailed(null);
}
}
}.execute();
} else {
//TODO
//Handle error
loadFailed(getString(R.string.err_load_s, getString(R.string.frame)));
}
} else if (VolleyRestClientUtils.STATUS_RESOURCE_NOT_FOUND.equals(status)) {
hasMore = false;
loadSucceed();
} else {
loadFailed(getString(R.string.err_load_s, getString(R.string.frame)));
}
} catch (Exception e) {
Log.e(LOG_TAG, "Exception:" + e.getMessage());
loadFailed(getString(R.string.err_load_s, getString(R.string.frame)));
}
}
#Override
public void onJSONError(String responseString) {
loadFailed(getString(R.string.err_load_s, getString(R.string.frame)));
}
#Override
public void onFailure(String errMessage, int statusCode, Map<String, String> headers, byte[] responseBytes) {
loadFailed(getString(R.string.err_load_s, getString(R.string.frame)));
}
});
Whereas loadSucceed() has this following code:
if (this.recyclerView != null) {
final RecyclerView.Adapter adapter = recyclerView.getAdapter();
if (adapter != null) {
adapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
#Override
public void onChanged() {
super.onChanged();
Log.i(DefaultRecyclerFragment.this.getClass().getName(), "onChanged");
adapter.unregisterAdapterDataObserver(this);
isLoading = false;
}
public void onItemRangeRemoved(int positionStart, int itemCount) {
Log.i(DefaultRecyclerFragment.this.getClass().getName(), "onItemRangeRemoved:" + positionStart + ", itemcount:" + itemCount);
adapter.unregisterAdapterDataObserver(this);
isLoading = false;
}
});
if (adapter instanceof CursorRecyclerAdapter && loadMoreView != null) {
((CursorRecyclerAdapter) adapter).removeFooter(loadMoreView);
}
}
}
I've put the code to initialize the loader in the onResume() method of each fragment:
int id = 100+Integer.valueOf(sort);
Loader l = getLoaderManager().getLoader(id);
Log.i("loader_callback_"+sort, "success loading volley "+l);
if(l == null) {
getLoaderManager().restartLoader(id, null, this);
}
My problem is that there seems to be some sort of race condition happening, that the currently viewed fragment's adapter seem to be updated twice, and sometimes thrice. The initial cursor fetched by the Fragment's Loader has 10 rows, sure, but after the update, most of the time it only has 7 of the 21 rows expected to be put in.
I thought all the ContentResolvers' operations are synchronous (can only be done one after another, not simultaneously). What's going on here?
EDIT: Should I just put the loader init code in the loadSuccess() callback?
EDIT2: I should note that these Fragments extend android.support.v4.app.Fragment, and I'm using the version 27.1.1 of the Support Library.

UI didn't updated using Rxjava with CompositeSubscription

I have used rxjava and retrofit to load data from backend and update the UI.
But there is no data displayed on section view. I have tested it, and the backend data load successful and the UI can be updated using fake data.
Are there something wrong when I use Rxjava?
private void retrieveCardInfo(String stripeId, String userToken) {
subscriptions.add(NetworkUtil.getRetrofit(userToken).getCustomerInfo(new GetCustomer(stripeId))
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(this::handleCustomerResponse, this::handleError));
}
private void handleCustomerResponse(CreateStripeCustomerResponse response) {
if (response.getSuccess()) {
updateCardList(response);
bankSection.setState(Section.State.EMPTY);
} else {
Utils.toast(this,"Get credit card failed");
}
}
private void updateCardList(CreateStripeCustomerResponse response) {
List<CardInfo> cardList = response.getCustomer().getSources().getData();
if (cardList == null || cardList.size() == 0) {
cardSection.setState(Section.State.EMPTY);
} else {
list = new ArrayList<>();
for (int i = 0; i < cardList.size(); i++) {
CardInfo cardInfo = cardList.get(i);
String brand = cardInfo.getBrand();
String subTitle = cardInfo.getFunding() + "****" + cardInfo.getLast4();
list.add(new PaymentAccountItem(brand, subTitle, cardDrawable.get(brand)));
}
list.add(new PaymentAccountItem("title", "subtitle", R.drawable.ic__credit_amex_svg));
cardSection.swipeData(list);
}
}
private void handleError(Throwable throwable) {
}
// works fine without sectionedAdapter.notifyDataSetChanged(); when using fake data,
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_payment);
ButterKnife.bind(this);
subscriptions = new CompositeSubscription();
initialToolbar();
initialRecyclerView();
initialPaymentData();
}
private void initialPaymentData() {
stripeIdAndToken = Utils.getStripeIdAndToken(this);
if (TextUtils.isEmpty(stripeIdAndToken.first)) {
cardSection.setState(Section.State.EMPTY);
bankSection.setState(Section.State.EMPTY);
} else {
initialCardDrawableResource();
retrieveCardInfo(stripeIdAndToken.first, stripeIdAndToken.second);
}
// fake data here
// initialCardDrawableResource();
// list = new ArrayList<>();
// list.add(new PaymentCreditCardItem("Visa", "123456", 10, 2018, cardDrawable.get("Visa")));
// cardSection.swipeData(list);
}
private void initialCardDrawableResource() {
cardDrawable = new HashMap<>();
cardDrawable.put("Visa", R.drawable.ic_visa_svg);
cardDrawable.put("Discover", R.drawable.ic_discover_svg);
cardDrawable.put("American Express", R.drawable.ic__credit_amex_svg);
cardDrawable.put("Mastercard", R.drawable.cio_ic_mastercard);
}
private void retrieveCardInfo(String stripeId, String token) {
subscriptions.add(NetworkUtil.getRetrofit(token).getCustomerInfo(new GetCustomer(stripeId))
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(this::handleCustomerResponse, this::handleError));
}
private void handleCustomerResponse(CreateStripeCustomerResponse response) {
if (response.getSuccess()) {
updateCardList(response);
} else {
Utils.toast(this, "Get credit card failed");
}
}
private void updateCardList(CreateStripeCustomerResponse response) {
List<CardInfo> cardList = response.getCustomer().getSources().getData();
if (cardList == null || cardList.size() == 0) {
cardSection.setState(Section.State.EMPTY);
} else {
list = new ArrayList<>();
for (int i = 0; i < cardList.size(); i++) {
CardInfo cardInfo = cardList.get(i);
String brand = cardInfo.getBrand();
String cardNum = cardInfo.getFunding() + "****" + cardInfo.getLast4();
list.add(new PaymentCreditCardItem(brand, cardNum, cardInfo.getExpMonth(), cardInfo.getExpYear(), cardDrawable.get(brand)));
}
cardSection.swipeData(list);
sectionedAdapter.notifyDataSetChanged();
}
}
private void handleError(Throwable throwable) {
}
private void initialRecyclerView() {
sectionedAdapter = new SectionedRecyclerViewAdapter();
cardSection = new PaymentCardAndAccountSection(this, R.layout.header_card, R.layout.payment_card_empty_view);
bankSection = new PaymentCardAndAccountSection(this, R.layout.header_bank, R.layout.payment_account_empty_view);
sectionedAdapter.addSection(cardSection);
sectionedAdapter.addSection(bankSection);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(sectionedAdapter);
bankSection.setState(Section.State.EMPTY);
}
private void initialToolbar() {
toolbar.setTitle("Payment");
toolbar.setNavigationIcon(R.drawable.ic_back_svg);
setSupportActionBar(toolbar);
}
#Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
#OnClick(R.id.fab_add_payment)
void launchAddPaymentDialog() {
AddPaymentDialogFragment addPaymentDialogFragment = AddPaymentDialogFragment.newInstance();
addPaymentDialogFragment.setStyle(DialogFragment.STYLE_NO_FRAME, 0);
addPaymentDialogFragment.show(getSupportFragmentManager(), "dialog");
}
#Override
public void onPause() {
super.onPause();
if (subscriptions != null) {
subscriptions.clear();
}
}

Do you use an adapter? In this case adapter.notifyDataSetChanged();
Also, print yout error: throwable.printStackTrace(); in order to see if something goes wrong.

You need to add .observeOn(AndroidSchedulers.mainThread()) after you write subsribeOn() to tell your observable to perform your onNext callback on UI thread/MainThread.

How to manually call observer.onNext in rxJava

I am relatively new to RxJava/RxAndroid. I have been using AsyncTask to do my long running tasks before now.
I have converted most of my AsyncTask to RxJava but this one.
The particular problem I am having is calling something like AsyncTask's publishProgress(params); in
the background thread. I need to do this to update the progress of a ProgressBar.
First this is the code in AsyncTask
private static class AddBooksToDatabase extends AsyncTask<String, String, String> {
//dependencies removed
AddBooksToDatabase(AddBooksDbParams params) {
//Removed assignment codes
}
#Override
protected String doInBackground(String... strings) {
//Initializing custom SQLiteOpenHelper and SQLite database
File mFile = new File(mFolderPath);
int booksSize = getFilesInFolder(mFile).size();
String[] sizeList = {String.valueOf(booksSize)};
//The first publishProgress is used to set the max of the progressbar
publishProgress(sizeList);
for (int i = 0; i < booksSize; i++) {
//publishProgress with current item, current file
publishProgress(String.valueOf(i), getFilesInFolder(mFile).get(i).getName());
//Inserting current items in database. Code removed
}
return null;
}
#Override
protected void onPreExecute() {
//Show ProgressBar
}
#Override
protected void onPostExecute(String s) {
//Hide ProgressBar
}
#Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
if (values.length == 1) {
//The first call to publishProgress
mProgressBar.setMax(Integer.parseInt(values[0]));
} else {
//Subsequent calls to publish progress
Log.i(TAG, "Current item is " + values[0] + " and current file is " + values[1]);
infoText.setText(values[1]);
mProgressBar.setProgress(Integer.parseInt(values[0]), true);
}
}
#Override
protected void onCancelled() {
cancel(true);
}
}
Code Using RxJava
final Observable<String[]> addBooksObserver = Observable.create(new Observable.OnSubscribe<String[]>() {
#Override
public void call(Subscriber<? super String[]> subscriber) {
subscriber.onNext(setAddSubscription());
subscriber.onCompleted();
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread());
private String[] setAddSubscription() {
S//Initializing custom SQLiteOpenHelper and SQLite database
File mFile = new File(mFolderPath);
int booksSize = getFilesInFolder(mFile).size();
String[] sizeList = {String.valueOf(booksSize)};
//The first publishProgress is used to set the max of the progressbar
addBooksObserver.doOnNext(addReturnParams(String.valueOf(sizeList.length), null, null));
for (int i = 0; i < booksSize; i++) {
EpubReader reader = new EpubReader();
//publishProgress with current item, current file*
addBooksObserver.doOnNext(addReturnParams(String.valueOf(sizeList.length),
String.valueOf(i), getFilesInFolder(mFile).get(i).getName()));
//Inserting current item in database. Code removed
}
return null;
}
private String[] addReturnParams(String totalItems, String currentItem, String currentFile) {
return new String[]{totalItems, currentItem, currentFile};
}
The problem is that lines addBooksObserver.doOnNext(addReturnParams( are displaying this error
doOnNext (rx.functions.Action1) cannot be applied to (java.lang.String[])
I don't know have any idea how to fix this because I thought that since setAddSubscription() and addReturnParams(String totalItems, String currentItem, String currentFile) are returning String array then this shouldn't be a problem. Please can you help me out?

you just have to pass the values to the onNext method of your subscriber, not the doOnNext method of your observable!
you also have to subscribe to the service. try something like this for your obserable:
Observable.create(new Observable.OnSubscribe<String[]>() {
#Override
public void call(Subscriber<? super String[]> subscriber) {
setAddSubscription(subscriber);
subscriber.onCompleted();
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<String[]>() {
#Override
public void onCompleted() {
// handle 'oparation is done'
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(String[] values) {
if (values.length == 1) {
//The first call to publishProgress
mProgressBar.setMax(Integer.parseInt(values[0]));
} else {
//Subsequent calls to publish progress
Log.i(TAG, "Current item is " + values[0] + " and current file is " + values[1]);
infoText.setText(values[1]);
mProgressBar.setProgress(Integer.parseInt(values[0]), true);
}
}
});
you also need to modify your private methods a little bit:
private void setAddSubscription(Subscriber<? super String[]> subscriber) {
//Initializing custom SQLiteOpenHelper and SQLite database
File mFile = new File(mFolderPath);
int booksSize = getFilesInFolder(mFile).size();
String[] sizeList = {String.valueOf(booksSize)};
//The first publishProgress is used to set the max of the progressbar
subscriber.onNext(addReturnParams(String.valueOf(sizeList.length), null, null));
for (int i = 0; i < booksSize; i++) {
EpubReader reader = new EpubReader();
//publishProgress with current item, current file*
subscriber.onNext(addReturnParams(String.valueOf(sizeList.length),
String.valueOf(i), getFilesInFolder(mFile).get(i).getName()));
//Inserting current item in database. Code removed
}
}
private String[] addReturnParams(String totalItems, String currentItem, String currentFile) {
return new String[]{totalItems, currentItem, currentFile};
}

You can use Subject to call onNext() manually like this:
Subject<Event> event = Subject.create();
Now call the onNext() for sending event like:
event.onNext("event");
Finally you can return Observable by using this code:
event.toFlowable(BackpressureStrategy.LATEST)
.toObservable();

Your Observer should be like Observable.create(new Observable.OnSubscribe<String>() & in your call method you should loop through the StringArray & pass it to onNext for example:
#Override
public void call(Subscriber<? super String> subscriber) {
for(String val : setAddSubscription()) {
subscriber.onNext(val);
}
subscriber.onCompleted();
}
now onNext shall return you individual items & onCompleted will be called upon the loop is finished.
Edit
myObserver.subscribe(new Subscriber<String>() {
#Override
public void onCompleted() {
// handle completion.
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(String value) {
// do whatever with each value passed to onNext
}
});

Observable.create(emitter -> {
for (int i = 0; i < 10; i++) {
int[] ii = {i, i * 2};
emitter.onNext(ii);
}
emitter.onComplete();
}).observeOn(AndroidSchedulers.mainThread()).subscribeOn(Schedulers.io()).subscribe(o -> {
// update progress
int[] i = (int[]) o;
Toast.makeText(SearchActivity.this, "oftad " + i[0] + " - " + i[1], Toast.LENGTH_SHORT).show();
}, t -> {
// on error
Toast.makeText(SearchActivity.this, t.getMessage(), Toast.LENGTH_SHORT).show();
}, () -> {
// progress tamom shod
Toast.makeText(SearchActivity.this, "completed", Toast.LENGTH_SHORT).show();
});

How to call a asyncTask several times inside a loop- one after another

Actually what i am trying to do is that call an asyncTask several times inside a loop. So, first time the asyncTask will start immediately and from second time onwards, it will check whether the AsyncTask has been finished-if finished than again call it with different values.
Below is my code for the activity:
In onCreate()
btnUpload.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
count_response = 0;
newUploadWithSeparate();
}
});
The newUploadWithSeparate() method:
private void newUploadWithSeparate()
{
responseString_concat = "";
if(filePath.length > 0)
{
for(int i=0;i<filePath.length;i++)
{
count_response = i;
if(i == 0)
{
uploadAsync.execute(filePath[0]);
mHandler = new Handler() {
#Override public void handleMessage(Message msg) {
String s=(String)msg.obj;
Log.d("logIMEI","\n Response from Asynctask: " + s);
str_response_fromAsync = s;
}
};
}
else
{
uploadAsync.getStatus();
while(uploadAsync.getStatus() == AsyncTask.Status.RUNNING) // this while loop is just to keep the loop value waitining for finishing the asyncTask
{
int rx = 0;
}
if(uploadAsync.getStatus() != AsyncTask.Status.RUNNING)
{
if(uploadAsync.getStatus() == AsyncTask.Status.FINISHED)
{
if(str_response_fromAsync != "" || !str_response_fromAsync.equals("") || !str_response_fromAsync.isEmpty())
{
uploadAsync.execute(filePath[i]);
x = i;
mHandler = new Handler() {
#Override public void handleMessage(Message msg)
{
String s=(String)msg.obj;
Log.d("logIMEI","\n Response from Asynctask_" + x + ": " + s);
str_response_fromAsync = s;
}
};
}
}
}
}
}
}
}
And the asyncTask:
private class UploadFileToServer extends AsyncTask<String, Integer, String>
{
#Override
protected void onPreExecute()
{
super.onPreExecute();
}
#Override
protected String doInBackground(String... params)
{
return uploadFile(params[0]);
}
private String uploadFile(String pr)
{
//inside here calling webservice and getting a response string as result.
MyWebsrvcClass mycls = new MyWebsrvcClass();
return responseString_concat = mycls.Call(xxx,yyy) ;
}
#Override
protected void onPostExecute(String result)
{
Log.d("logIMEI" , "\n count_response : "+ count_response + " fileprath_len : " + filePath.length);
Message msg=new Message();
msg.obj=result.toString();
mHandler.sendMessage(msg);
super.onPostExecute(result);
}
}
Now the problem is that its not working as expected. The first time when value of i is equals 0 than the AsyncTask gets called and after that its not getting called anymore.
Plus, when first time AsyncTask is called- its still not directly entering to onPostExecute(). When the loop ends totally and newUploadWithSeparate() method ends then the onPostExecute() is working.
Any solutions for this or any other way to do this job done for using AsyncTask inside loop?

You cannot call execute() on the same object more than once. So create a new instance of UploadFileToServer for each iteration of the loop.

Disable loading in Pull to refresh listview

I am having Pull to Refresh https://github.com/chrisbanes/Android-PullToRefresh as given in this link. Everything works fine. But when my list item finishes, the loading icon and pull to refresh label is still visible. So, how to disable the scrolling when end of list reached?
mainListView.setOnRefreshListener(new OnRefreshListener() {
#Override
public void onRefresh(PullToRefreshBase refreshView) {
String total_bk_count = subCategory .getTotal_Book_Count();
count_of_book = Integer.parseInt(total_bk_count);
listCountt = mainbooksAdpater.getCount();
Log.e("StroreActivity","Total book count---====----====---+"+count_of_book);
Log.e("StroreActivity","list Count---====----====---+"+listCountt);
if(listCountt < count_of_book)
{
int bookCount = Common.getBookCountNumber();
Common.setBookCount(bookCount+1);
String refresh_Pull_Url = Common.getUrlForeCategoryBooks(id, Common.NUMBER_OF_BOOKS_PER_REQUEST);
Log.e("Rathis to Check url", Common.getUrlForeCategoryBooks(id, Common.NUMBER_OF_BOOKS_PER_REQUEST));
PulltoRefreshAsync onCatBooksTaskScroll = new PulltoRefreshAsync(Common.getUrlForeCategoryBooks(id, Common.NUMBER_OF_BOOKS_PER_REQUEST));
onCatBooksTaskScroll.execute();
Log.e("StroreActivity","Total Book count::" + book_count_no);
}
else
{
mainListView.setMode(Mode.DISABLED);
Toast.makeText(getApplicationContext(), "end of list", Toast.LENGTH_SHORT).show();
}
}
});
Asynctask Class:
public class PulltoRefreshAsync extends AsyncTask<Object,Object,Object> {
int refreshCount;
String refresh_URL;
public PulltoRefreshAsync(String url) {
refresh_URL = url;
}
/*
* PulltoRefreshAsync(int i) { refreshCount = i; }
*/
#Override
protected void onPreExecute() {
super.onPreExecute();
Log.e("Checking Purpose", refresh_URL);
}
#Override
protected String doInBackground(Object... arg0) {
JsonParserRefresh jp = new JsonParserRefresh();
Log.e("StroreActivity","Array to String::" + refresh_URL);
String jsonString = jp.getJSONFromURL(refresh_URL);
Log.e("StroreActivity","JsonString::" + jsonString);
jsonParseForCategoryBooksGridScroll(jsonString);
return null;
}
#Override
protected void onPostExecute(Object result) {
super.onPostExecute(result);
/*
* if(mProgressDialog.isShowing()) { mProgressDialog.dismiss(); }
*/
final MainBooksAdapter mainbooksAdpater = new MainBooksAdapter(
StoreActivity.this, R.layout.aa, mainBooksList);
final int old_pos = mainListView.getRefreshableView()
.getFirstVisiblePosition() + 1;
mainListView.setAdapter(mainbooksAdpater);
tvvisiblebookCount.setText("" + mainbooksAdpater.getCount());
/*if(listCountt < count_of_book)
{
mainListView.setMode(Mode.DISABLED);*/
mainListView.post(new Runnable() {
#Override
public void run() {
mainListView.onRefreshComplete();
mainListView.getRefreshableView().setSelection(old_pos);
}
});
//}
mainbooksAdpater.notifyDataSetChanged();
}
}

For other people who might have similat issue:
you don't have to implement it this way
mainListView.post(new Runnable() {
#Override
public void run() {
mainListView.onRefreshComplete();
mainListView.getRefreshableView().setSelection(old_pos);
}
});
instead do just like this :
mainListView.onRefreshComplete();
one more thing I noticed, instead of saving the old pos value to get back to it, why not just use notifyDataSetChanged it leaves the position of the list the way it is, just try not to re-instanciate you list, i.e: mainBooksList = ..., instead try this:
mainBooksList.clear();
mainBooksList.addAll(YOUR DATA);
adapter.notifyDataSetChanged();
voila!
hope this helps someone