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While fetching data and storing it into sqlite db the UI of my app freezes

Hello My app is freezes ui for some seconds while it is fetching data from network and stores it in db and then shows it in recyclerview. For fetching data from network I am using retrofit and for storing it and fetching form db Room library. Both with the help of MVVM pattern. Is there a way to remoove the UI freeze?
Here is my code:
In the Mainactivity when clicking download btn
downloadBtn.setOnClickListener(v ->
eventsViewModel.insertEvents(this));
Viewmodel class:
public void insertEvents(Context context){
final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
String token = preferences.getString("token", "");
final Map<String,String> queryData = new HashMap<>();
queryData.put("token", token);
Call<EventsResponse> call = RetrofitClient.getmInstance().getApi().getEvents(queryData);
call.enqueue(new Callback<EventsResponse>() {
#Override
public void onResponse(Call<EventsResponse> call, Response<EventsResponse> response) {
if (response.code() == 401){
String email = preferences.getString("email", "");
String password = preferences.getString("password", "");
Call<LoginResponse> call1 = RetrofitClient.getmInstance().getApi().loginuser(email, password);
call1.enqueue(new Callback<LoginResponse>() {
#Override
public void onResponse(Call<LoginResponse> call, Response<LoginResponse> response) {
if (response.code() == 200){
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(context); // 0 - for private mode
SharedPreferences.Editor editor = pref.edit();
editor.putString("token", response.body().getToken());
editor.apply();
insertEvents(context);
}
else {
}
}
#Override
public void onFailure(Call<LoginResponse> call, Throwable t) {
}
});
}
if (response.code() == 200){
eventList = response.body().getData();
EventsTable eventsTable = new EventsTable();
TicketDatesTable ticketDatesTable = new TicketDatesTable();
for (int i = 0; i < eventList.size(); i++) {
eventsTable.setEvent_id(eventList.get(i).getId());
eventsTable.setTitle_tk(eventList.get(i).getTitle_tk());
eventsTable.setTitle_ru(eventList.get(i).getTitle_ru());
eventsTable.setImageURL("https://bilettm.com/" + eventList.get(i).getImage_url());
eventsTable.setStart_date(eventList.get(i).getStart_date());
eventsTable.setEnd_date(eventList.get(i).getEnd_date());
eventsTable.setSales_volume(eventList.get(i).getEnd_date());
eventsTable.setOrganiser_fees_volume(eventList.get(i).getOrganiser_fees_volume());
eventsTable.setViews(eventList.get(i).getViews());
eventsTable.setSales_volume(eventList.get(i).getSales_volume());
eventsTable.setIs_live(eventList.get(i).getIs_live());
if (!eventList.get(i).getTicket_dates().isEmpty()) {
showTimeList = eventList.get(i).getTicket_dates();
int b = 0;
while (b < showTimeList.size()) {
ticketDatesTable.setEvent_id(showTimeList.get(b).getEvent_id());
ticketDatesTable.setTicket_date(showTimeList.get(b).getTicket_date());
insertTicketDates(ticketDatesTable);
try {
Thread.sleep(150);
} catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
b++;
}
}
insert(eventsTable);
try {
Thread.sleep(150);
} catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}
}
#Override
public void onFailure(Call<EventsResponse> call, Throwable t) {
}
});
}
public void insert(EventsTable data){
repository.insertEvents(data);
}
public void insertTicketDates(TicketDatesTable ticketDatesTable){
repository.insertTicketDates(ticketDatesTable);
Here is my repository :
public void insertEvents(EventsTable data){
new EventInsertion(eventsDAO).execute(data);
}
private static class EventInsertion extends AsyncTask<EventsTable, Void, Void> {
private EventsDAO eventsDAO;
private EventInsertion(EventsDAO eventsDAO) {
this.eventsDAO = eventsDAO;
}
#Override
protected Void doInBackground(EventsTable... eventsTables) {
eventsDAO.insertEvents(eventsTables[0]);
return null;
}
}
public void insertTicketDates(TicketDatesTable data){
new TicketDatesInsertion(eventsDAO).execute(data);
}
private static class TicketDatesInsertion extends AsyncTask<TicketDatesTable, Void, Void> {
private EventsDAO eventsDAO;
private TicketDatesInsertion(EventsDAO eventsDAO) {
this.eventsDAO = eventsDAO;
}
#Override
protected Void doInBackground(TicketDatesTable... ticketDatesTables) {
eventsDAO.insertTicketDates(ticketDatesTables[0]);
return null;
}
}
Here is my DAO:
#Insert(onConflict = OnConflictStrategy.REPLACE)
void insertEvents(EventsTable data);
#Insert(onConflict = OnConflictStrategy.REPLACE)
void insertTicketDates(TicketDatesTable datesTable);
I think it freezes when it is storing it into sqlite db

I found my problem. It was initializing entity before starting for loop:
BEFORE:
EventsTable eventsTable = new EventsTable();
for (int i = 0; i < eventList.size(); i++) {
INSERT();
}
AFTER:
for (int i = 0; i < eventList.size(); i++) {
EventsTable eventsTable = new EventsTable();
INSERT();
}

A better solution would be to collect all your required objects in an ArrayList and then pass it on to the AsyncTask and from there to DAO for bulk insertion.
And remove all Thread.sleep(150) statements as they serve no purpose.

why you are using this Thread.sleep(150);Call is already a background task in retrofit

Display and hide progress bar using MVVM pattern

I am working with MVVM pattern. I have just started it and i have done it successfully.
But I don't understand how to add progress bar for showing and hide as we normally do for API calls.
I am not using data binding. So how can i use progress bar for showing and hide it.
For Login
public class LoginRepository {
private DATAModel dataModel = new DATAModel();
private MutableLiveData<DATAModel> mutableLiveData = new MutableLiveData<>();
private Application application;
public LoginRepository(Application application) {
this.application = application;
}
public MutableLiveData<DATAModel> getMutableLiveData(String username, String password) {
APIRequest apiRequest = RetrofitRequest.getRetrofit().create(APIRequest.class);
JsonLogin jsonLogin = new JsonLogin(Constants.DEVICE_TYPE, Functions.getDeviceId(application.getApplicationContext()), Constants.APP_VERSION, Constants.API_VERSION, Functions.getTimeStamp(), Functions.getDeviceModel(), Build.VERSION.RELEASE, username, password);
Call<APIResponseLogin> call = apiRequest.getUsersDetails(jsonLogin);
call.enqueue(new Callback<APIResponseLogin>() {
#Override
public void onResponse(Call<APIResponseLogin> call, Response<APIResponseLogin> response) {
APIResponseLogin apiResponse = response.body();
if (apiResponse != null && apiResponse.getStatuscode() == 0) {
if (apiResponse.getDataModel() != null) {
dataModel = apiResponse.getDataModel();
mutableLiveData.setValue(dataModel);
}
} else if (apiResponse != null && apiResponse.getStatuscode() == 1) {
Log.v("AAAAAAAAA", apiResponse.getStatusmessage());
}
}
#Override
public void onFailure(Call<APIResponseLogin> call, Throwable t) {
Log.v("ErrorResponse", t.getMessage() + " : " + call.request().toString());
}
});
return mutableLiveData;
}
Activity Code
void loginCall() {
loginViewModel.getUserDetails(editTextUsername.getText().toString().trim(), editTextPassword.getText().toString().trim()).observe(this, new Observer<DATAModel>() {
#Override
public void onChanged(#Nullable DATAModel dataModel) {
if (dataModel != null) {
Userdetails userdetails = dataModel.getUserdetails();
List<ContactTypes> contactTypes = dataModel.getContactTypes();
if (userdetails != null) {
MySharedPreferences.setCustomPreference(LoginActivity.this, Constants.SHAREDPREFERENCE_USERDETAILS, userdetails);
MySharedPreferences.setStringPreference(LoginActivity.this, Constants.SHAREDPREFERENCE_USER_ID, userdetails.getUserId());
}
if (contactTypes != null) {
MySharedPreferences.setCustomArrayList(LoginActivity.this, Constants.SHAREDPREFERENCE_CONTACTTYPES, contactTypes);
}
Intent i = new Intent(LoginActivity.this, MainActivity.class);
startActivity(i);
finish();
}
}
});
}
Advanced help would be appreciated!

When you call api that time you have to take one live variable which shows your api is in loading mode or not and after success or failure you have to update that variable.
After observe that variable in your activity or fragment class and show or hide your progress.
public class LoginRepository {
private DATAModel dataModel = new DATAModel();
private MutableLiveData<DATAModel> mutableLiveData = new MutableLiveData<>();
private Application application;
private MutableLiveData<Boolean> progressbarObservable;
public LoginRepository(Application application) {
this.application = application;
}
public MutableLiveData<DATAModel> getMutableLiveData(String username, String password) {
// add below line
progressbarObservable.value = true
APIRequest apiRequest = RetrofitRequest.getRetrofit().create(APIRequest.class);
JsonLogin jsonLogin = new JsonLogin(Constants.DEVICE_TYPE, Functions.getDeviceId(application.getApplicationContext()), Constants.APP_VERSION, Constants.API_VERSION, Functions.getTimeStamp(), Functions.getDeviceModel(), Build.VERSION.RELEASE, username, password);
Call<APIResponseLogin> call = apiRequest.getUsersDetails(jsonLogin);
call.enqueue(new Callback<APIResponseLogin>() {
#Override
public void onResponse(Call<APIResponseLogin> call, Response<APIResponseLogin> response) {
// add below line
progressbarObservable.value = false
APIResponseLogin apiResponse = response.body();
if (apiResponse != null && apiResponse.getStatuscode() == 0) {
if (apiResponse.getDataModel() != null) {
dataModel = apiResponse.getDataModel();
mutableLiveData.setValue(dataModel);
}
} else if (apiResponse != null && apiResponse.getStatuscode() == 1) {
Log.v("AAAAAAAAA", apiResponse.getStatusmessage());
}
}
#Override
public void onFailure(Call<APIResponseLogin> call, Throwable t) {
// add below line
progressbarObservable.value = false
Log.v("ErrorResponse", t.getMessage() + " : " + call.request().toString());
}
});
return mutableLiveData;
}
}
Now, observe above variable in activity or fragment and based on that value hide or show your progress bar
public class LoginActivity extends AppCompatActivity {
...
#Override
protected void onCreate(Bundle savedInstanceState) {
...
observeLogin();
}
#Override
public void onClick(View view)
{
switch (view.getId()) {
case R.id.button_login:
// Do something
loginCall();
}
}
private void observeLogin() {
loginViewModel.progressbarObservable().observe(this, new Observer<Boolean>() {
#Override
public void onChanged(final Boolean progressObserve) {
if(progressObserve){
show your progress
}
else {
hide your progress
}
}
});
}
void loginCall() {
loginViewModel.getUserDetails(editTextUsername.getText().toString().trim(), editTextPassword.getText().toString().trim()).observe(this, new Observer<DATAModel>() {
#Override
public void onChanged(#Nullable DATAModel dataModel) {
if (dataModel != null) {
Userdetails userdetails = dataModel.getUserdetails();
List<ContactTypes> contactTypes = dataModel.getContactTypes();
if (userdetails != null) {
MySharedPreferences.setCustomPreference(LoginActivity.this, Constants.SHAREDPREFERENCE_USERDETAILS, userdetails);
MySharedPreferences.setStringPreference(LoginActivity.this, Constants.SHAREDPREFERENCE_USER_ID, userdetails.getUserId());
}
if (contactTypes != null) {
MySharedPreferences.setCustomArrayList(LoginActivity.this, Constants.SHAREDPREFERENCE_CONTACTTYPES, contactTypes);
}
Intent i = new Intent(LoginActivity.this, MainActivity.class);
startActivity(i);
finish();
}
}
});
}
}

I find it easier to write my own callback interface in this situation. Just not that this will be done synchronously so all will wait until your api call responds. But in such a case, a progress dialog would be havin the similar effect.
1.Create inteface:
public interface ProgressCallback{
void onDone(String message);
void onFail(String message);
}
Now in your method where you call the API
loginUser(String name, String password, ProgressCallback
progressCallback){
call.enqueue(new Callback<LoginData>() {
#RequiresApi(api = Build.VERSION_CODES.O)
#Override
public void onResponse(Call<LoginData> call, Response<LoginData> response) {
progressCallBack.onSuccess(response.message());
}
#Override
public void onFailure(Call<LoginData> call, Throwable t) {
progressCallBack.onFail(t.getMessage());
}
});
Now when you call the method
loginUser("John#doe.com", "applesgravity", new ProgressCallBack() {
#Override
public void onSuccess(String message) {
progressBar.setVisibility(View.INVISIBLE);
}
#Override
public void onFail(String message) {
progressBar.setVisibility(View.INVISIBLE);
}
});

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.

scroll pagination with Laravel API

I am using Laravel API with paginated data in Android...
I want to get auto paginated data.
e.g. data on first page load first and when I scroll down, next pages load continously!

You can use laravel default pagination method instate of get rows.
For example i want show users list:
//instate of :
$users = User::get();
//Use :
$users = User::paginate();
more info at : laravel site
https://laravel.com/docs/5.5/pagination

You can do so easily using the LengthAwarePaginator
protected function paginate(Collection $collection)
{
$rules = [
'per_page' => 'integer|min:2|max:50',
];
Validator::validate(request()->all(), $rules);
$page = LengthAwarePaginator::resolveCurrentPage();
$perPage = 15;
if (request()->has('per_page')) {
$perPage = (int) request()->per_page;
}
$results = $collection->slice(($page - 1) * $perPage, $perPage)->values();
$paginated = new LengthAwarePaginator($results, $collection->count(), $perPage, $page, [
'path' => LengthAwarePaginator::resolveCurrentPath(),
]);
$paginated->appends(request()->all());
return $paginated;
}
Make sure you import all the namespaces needed,
You can go ahead and paginate the collection thus
$collection = $this->paginate($collection);
Hope this helps

On Laravel Side
// Get Collection
$query = SomeModel::where('some_thing', "5")
->paginate(10);
return Response::json(array(
'some_result' => $query,
));
On Android Side (Retrofit Call)
#FormUrlEncoded
#POST
Call<JsonObject> getActions(
#Url String url);
On Android Side (Activity/Fragment)
public class NewTemplateActivity
extends AppCompatActivity {
// Recycler View
private SomeActionListAdapter someActionsAdapter;
private List<SomesomeActionListModel> listSomeActionModel;
private RecyclerView rv;
private Boolean isScrolling = false;
private int currentItems, totalItems, scrollOutItems;
private int pageNumber = 1;
private Boolean firstLoad = true;
private Boolean firstSearch = false;
private LinearLayoutManager manager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
// Init Recycler View
rv = findViewById(R.id.f_list_rv_list);
rv.setHasFixedSize(true);
listSomeActionModel = new ArrayList<>();
someActionsAdapter = new SomeActionListAdapter(
mContext,
listSomeActionModel);
manager = new LinearLayoutManager(mContext);
rv.setLayoutManager(manager);
rv.setAdapter(someActionsAdapter);
}
private void getSomeAction(
String url) {
if (firstLoad || firstSearch) {
listSomeActionModel.clear();
}
// Retrofit Call
Call<JsonObject> call = RetrofitClientLaravel.getInstance(mContext)
.discussGetApi()
.getSomeAction(url);
call.enqueue(new Callback<JsonObject>() {
#Override
public void onResponse(
Call<JsonObject> call,
Response<JsonObject> response) {
JSONObject jsonObject;
try {
jsonObject = new JSONObject(new Gson().toJson(response.body()));
// Get The Relevant Array
JSONObject jsonObject2 = jsonObject.getJSONObject("some_result");
JSONArray returnArray = jsonObject2.getJSONArray("data");
onScrolled();
if (!returnArray.isNull(0)) {
for (int l = 0; l < returnArray.length(); l++) {
if (returnArray.length() > 0) {
// Get The Json Object
JSONObject returnJSONObject = returnArray.getJSONObject(l);
// Get Details
String id = returnJSONObject.optString("SomesomeAction_id");
// Populate The Array List
listSomeActionModel.add(new SomesomeActionListModel(id));
}
}
}
if (firstLoad || firstSearch) {
someActionsAdapter = new SomeActionListAdapter(
mContext,
listSomeActionModel);
rv.setAdapter(someActionsAdapter);
}
someActionsAdapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void onFailure(
Call<JsonObject> call,
Throwable t) {
}
});
}
public void onScrolled() {
rv.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(
RecyclerView recyclerView,
int newState) {
super.onScrollStateChanged(
recyclerView,
newState);
if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {
isScrolling = true;
}
}
#Override
public void onScrolled(
RecyclerView recyclerView,
int dx,
int dy) {
super.onScrolled(
recyclerView,
dx,
dy);
currentItems = manager.getChildCount();
totalItems = manager.getItemCount();
scrollOutItems = manager.findFirstVisibleItemPosition();
if (isScrolling && (currentItems + scrollOutItems == totalItems)) {
isScrolling = false;
firstLoad = false;
firstSearch = false;
Toast.makeText(
mContext,
"Loading More...",
Toast.LENGTH_SHORT)
.show();
pageNumber++;
getSomeAction(Env.LARAVEL_MAIN_URL +
"/api/get_SomesomeActions" +
"?page=" +
pageNumber);
}
}
});
}
}

Store all the information at once using Realm in Background thread Android

I am developing an android app, where I am using Relam as local Database. I have rest api one for all the user information and other is for news information. I have two buttons. one for showing the user information and other is for showing the news information. Now, with my code what is done, after login, I need to click the button at first for user information and news information accordingly and then I can see those images and news. but if I connection off, just after login, the data is not showing in the view. I am explaining my code in detail.Also I am having problem in image loading. How can I Make the funtionality so that user can get all the information just after login.I am reallly sorry for such a long code. It would be really helpful for me if someone tell me how can I modify my code to store all data in background thread, so that user get all information just after login.
The part of the login page where I want to start
private void loginUser(final String mEmail, final String mPassword) {
final GlobalClass globalClass = new GlobalClass();
globalClass.setEmail_info( mEmail );
setFilePath();
RequestQueue queue = Volley.newRequestQueue( LoginPage.this );
StringRequest strReq = new StringRequest( Request.Method.POST,
LOGIN_URL, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d( TAG, "Register Response: " + response.toString() );
//parse your response here
if (response.contains( "overview" )) {
showProgress( true );
globalClass.setImage_urlpath( Constants.HTTP.PHOTO_URL + mEmail);
String str = globalClass.readDatafromStorage();
Log.d("----After Login---",str);
if ( !str.contains("ACTIVATE") ) {
Log.d( "----After Login---", "After Login" );
}
SharedPreferences.Editor editor = sharedpreferences.edit();
editor.putString(KEY_EMAIL, mEmail);
editor.putString(KEY_PASSWORD, mPassword);
editor.commit();
showProgress(false);
Intent loginIntent = new Intent(LoginPage.this, MainOptionPage.class);
loginIntent.putExtra(KEY_EMAIL, mEmail);
startActivity(loginIntent);
} else {
userEmail.setError(getString(R.string.error_incorrect_login));
userEmail.requestFocus();
}
}
}, new Response.ErrorListener() {
#Override
....
Here is my code for User Page
public class MyColleaguesPage extends AppCompatActivity implements ColleagueController.UserCallbackListener {
private List<MyColleagueModel> myColleagueList = new ArrayList<>();
private Realm colleagueRealm;
private RealmResults<MyColleagueModel> colleagueResult;
private List<MyColleagueModel> filteredModelList;
private RealmChangeListener realmListener;
private static final String DIALOG_TAG = "EmployeeDialog";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mycolleagues_layout);
configViews();
}
private void configViews() {
recyclerView = this.findViewById(R.id.colleagues_recycler);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(MyColleaguesPage.this));
recyclerView.setRecycledViewPool(new RecyclerView.RecycledViewPool());
colleagueRealm = Realm.getDefaultInstance();
RealmResults<MyColleagueModel> results = colleagueRealm.where(MyColleagueModel.class).findAll();
for (int i = 0; i < results.size(); i++) {
myColleagueList.add(results.get(i));
}
adapter = new MyColleaguesAdapter(myColleagueList,getApplicationContext());
//adapter = new MyColleaguesAdapter(myColleagueList,getApplicationContext());
Log.d( "adapter value is"+"", String.valueOf( adapter ) );
recyclerView.setAdapter(adapter);
}
//successful
#Override
public void onFetchStart() {
}
#Override
public void onFetchProgress(ColleagueModel colleague) {
//adapter.addColleague(colleague);
}
#Override
public void onFetchProgress(List<ColleagueModel> colleagueList) {
}
#Override
public void onFetchComplete() {
}
#Override
public void onFetchFailed() {
}
}
Here is my controller class for my colleague page
public class ColleagueController {
private static final String TAG = ColleagueController.class.getSimpleName();
private UserCallbackListener mListener;
private ColleagueResApiManager mApiManager;
Realm myColleague_realm;
public ColleagueController() {
mApiManager = new ColleagueResApiManager();
}
public void startFetching(){
myColleague_realm = Realm.getDefaultInstance();
mApiManager.getColleagueApi().getColleague(new Callback<String>() {
#Override
public void success(String s, Response response) {
Log.d(TAG, "JSON :: " + s);
try {
JSONArray array = new JSONArray(s);
for(int i = 0; i < array.length(); i++) {
JSONObject object = array.getJSONObject(i);
Log.d("-----Start Fetching---", object.optString( "name" ));
myColleague_realm.beginTransaction();
MyColleagueModel mycolleague = myColleague_realm.createObject( MyColleagueModel.class );
mycolleague.setName( object.optString( "name" ) );
.... data ) );
myColleague_realm.commitTransaction();
}
} catch (JSONException e) {
mListener.onFetchFailed();
}
// mListener.onFetchComplete();
}
#Override
public void failure(RetrofitError error) {
Log.d(TAG, "Error :: " + error.getMessage());
if (mListener != null) {
mListener.onFetchComplete();
}
}
});
}
public interface UserCallbackListener{
void onFetchComplete();
void onFetchFailed();
}
}
In the same way I have other page news option page where I am shoing the news data. Here is my news page.
public class NewsPage extends AppCompatActivity{
private RecyclerView recyclerView;
private NewsAdapter adapter;
private Realm newsRealm;
private List<NewsRealmModel> mNewsList;
private List<NewsRealmModel> filteredModelList;
private NewsController mController;
Constant constant;
SharedPreferences app_preferences;
int appTheme;
int themeColor;
int appColor;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView( R.layout.news_page_layout);
configViews();
}
private void configViews() {
recyclerView = this.findViewById(R.id.news_recycler);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(NewsPage.this));
recyclerView.setRecycledViewPool(new RecyclerView.RecycledViewPool());
Realm newsRealm = Realm.getDefaultInstance();
RealmResults<NewsRealmModel> temp = newsRealm.where(NewsRealmModel.class).findAll();
mNewsList = new ArrayList<>();
for (int i = 0; i < temp.size(); i++) {
mNewsList.add(temp.get(i));
}
adapter = new NewsAdapter(mNewsList,getApplicationContext());
Log.d( "adapter value is"+"", String.valueOf( adapter ) );
recyclerView.setAdapter(adapter);
}
}
And the new Controller Class
public class NewsController {
private static final String TAG = NewsController.class.getSimpleName();
private UserCallbackListener mListener;
private NewsRestApiManager mApiManager;
private AppImage appImages;
Realm myNews_realm;
ArrayList<String> title_list = new ArrayList<>();
GlobalClass globalClass = new GlobalClass();
public NewsController(UserCallbackListener listener) {
mListener = listener;
mApiManager = new NewsRestApiManager();
}
public void startFetching() {
myNews_realm = Realm.getDefaultInstance();
mApiManager.getNewsApi().getNews(new Callback<String>() {
#Override
public void success(String s, Response response) {
Log.d(TAG, "JSON :: " + s);
try {
JSONArray array = new JSONArray(s);
for (int i = 0; i < array.length(); i++) {
JSONObject jsonObject = array.getJSONObject(i);
Log.d("-----Start Fetching---", jsonObject.optString("title"));
if (!myNews_realm.isInTransaction()) {
myNews_realm.beginTransaction();
NewsRealmModel news = new NewsRealmModel();
....... data
}
myNews_realm.copyToRealm(news);
myNews_realm.commitTransaction();
mListener.onFetchProgressNews(news);
} else {
myNews_realm.commitTransaction();
}
}
} catch (JSONException e) {
mListener.onFetchFailed();
}
mListener.onFetchComplete();
}
#Override
public void failure(RetrofitError error) {
Log.d(TAG, "Error :: " + error.getMessage());
mListener.onFetchComplete();
}
});
}
public interface UserCallbackListener {
void onFetchProgressNews(NewsRealmModel news);
void onFetchComplete();
void onFetchFailed();
}
}

To do your database processing on a background thread using Volley, you need to extend Request<T> and do the Realm write in parseNetworkResponse method.
public class RealmGsonObjectRequest<T, M extends RealmModel> extends Response<Void> {
...
#Override
protected Response<Void> parseNetworkResponse(
NetworkResponse response) {
try {
String json = new String(response.data,
HttpHeaderParser.parseCharset(response.headers));
T data = gson.fromJson(json, clazz);
// write the downloaded data into the Realm on bg thread
try(Realm r = Realm.getDefaultInstance()) {
M model = mapper.toModel(data);
r.executeTransaction((realm) -> {
realm.insertOrUpdate(model);
});
}
return Response.success(null,
HttpHeaderParser.parseCacheHeaders(response)
);
} // handle errors
}
You might need a RealmGsonListRequest as well.
public class RealmGsonListRequest<T, M extends RealmModel> extends Response<Void> {
...
#Override
protected Response<Void> parseNetworkResponse(
NetworkResponse response) {
try {
String json = new String(response.data,
HttpHeaderParser.parseCharset(response.headers));
List<T> data = gson.fromJson(json, new TypeToken<ArrayList<T>>() {}.getType());
// write the downloaded data into the Realm on bg thread
try(Realm r = Realm.getDefaultInstance()) {
M model = mapper.toModel(data);
r.executeTransaction((realm) -> {
realm.insertOrUpdate(model);
});
}
return Response.success(null,
HttpHeaderParser.parseCacheHeaders(response)
);
} // handle errors
}
For more information, refer to the official Volley tutorial on how to create a custom Volley request type.