Running room DB inside AsyncTask gives an error











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Hi I am running some operation that copies data drom Firebase DB to local room DB.
Here is doInBackground part from my AsyncTask.



    @Override
protected Void doInBackground(Void... voids) {

contactList = getContactListFromPhone();

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("users");
databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


for (DataSnapshot userSnapshot : dataSnapshot.getChildren())
{
User user = userSnapshot.getValue(User.class);

if (contactList.containsKey(user.getPhone()))
{

UserDB userDB = new UserDB();
userDB.setName(user.getName());
userDB.setPhone(user.getPhone());
userDB.setToken(user.getToken());


//adding to database
DatabaseClient.getInstance(context.getApplicationContext()).getAppDatabase().userDao().insert(userDB);
}
}
}

@Override
public void onCancelled(@NonNull DatabaseError databaseError) {

}
});



return null;
}


But on line "DatabaseClient.getInstance...." I receiving an error:



Cannot access database on the main thread since it may potentially lock the UI for a long period of time


But I am already in AsyncTask, why is that?










share|improve this question






















  • It's not about AsyncTask but about Firebase. Firebase's onDataChange will be callen in MainThread and hence you DatabaseClient.getInstance is running in MainThread.
    – musooff
    Nov 16 at 1:16















up vote
0
down vote

favorite












Hi I am running some operation that copies data drom Firebase DB to local room DB.
Here is doInBackground part from my AsyncTask.



    @Override
protected Void doInBackground(Void... voids) {

contactList = getContactListFromPhone();

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("users");
databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


for (DataSnapshot userSnapshot : dataSnapshot.getChildren())
{
User user = userSnapshot.getValue(User.class);

if (contactList.containsKey(user.getPhone()))
{

UserDB userDB = new UserDB();
userDB.setName(user.getName());
userDB.setPhone(user.getPhone());
userDB.setToken(user.getToken());


//adding to database
DatabaseClient.getInstance(context.getApplicationContext()).getAppDatabase().userDao().insert(userDB);
}
}
}

@Override
public void onCancelled(@NonNull DatabaseError databaseError) {

}
});



return null;
}


But on line "DatabaseClient.getInstance...." I receiving an error:



Cannot access database on the main thread since it may potentially lock the UI for a long period of time


But I am already in AsyncTask, why is that?










share|improve this question






















  • It's not about AsyncTask but about Firebase. Firebase's onDataChange will be callen in MainThread and hence you DatabaseClient.getInstance is running in MainThread.
    – musooff
    Nov 16 at 1:16













up vote
0
down vote

favorite









up vote
0
down vote

favorite











Hi I am running some operation that copies data drom Firebase DB to local room DB.
Here is doInBackground part from my AsyncTask.



    @Override
protected Void doInBackground(Void... voids) {

contactList = getContactListFromPhone();

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("users");
databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


for (DataSnapshot userSnapshot : dataSnapshot.getChildren())
{
User user = userSnapshot.getValue(User.class);

if (contactList.containsKey(user.getPhone()))
{

UserDB userDB = new UserDB();
userDB.setName(user.getName());
userDB.setPhone(user.getPhone());
userDB.setToken(user.getToken());


//adding to database
DatabaseClient.getInstance(context.getApplicationContext()).getAppDatabase().userDao().insert(userDB);
}
}
}

@Override
public void onCancelled(@NonNull DatabaseError databaseError) {

}
});



return null;
}


But on line "DatabaseClient.getInstance...." I receiving an error:



Cannot access database on the main thread since it may potentially lock the UI for a long period of time


But I am already in AsyncTask, why is that?










share|improve this question













Hi I am running some operation that copies data drom Firebase DB to local room DB.
Here is doInBackground part from my AsyncTask.



    @Override
protected Void doInBackground(Void... voids) {

contactList = getContactListFromPhone();

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("users");
databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


for (DataSnapshot userSnapshot : dataSnapshot.getChildren())
{
User user = userSnapshot.getValue(User.class);

if (contactList.containsKey(user.getPhone()))
{

UserDB userDB = new UserDB();
userDB.setName(user.getName());
userDB.setPhone(user.getPhone());
userDB.setToken(user.getToken());


//adding to database
DatabaseClient.getInstance(context.getApplicationContext()).getAppDatabase().userDao().insert(userDB);
}
}
}

@Override
public void onCancelled(@NonNull DatabaseError databaseError) {

}
});



return null;
}


But on line "DatabaseClient.getInstance...." I receiving an error:



Cannot access database on the main thread since it may potentially lock the UI for a long period of time


But I am already in AsyncTask, why is that?







android multithreading android-room






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share|improve this question










asked Nov 15 at 16:05









Dim

1,06465494




1,06465494












  • It's not about AsyncTask but about Firebase. Firebase's onDataChange will be callen in MainThread and hence you DatabaseClient.getInstance is running in MainThread.
    – musooff
    Nov 16 at 1:16


















  • It's not about AsyncTask but about Firebase. Firebase's onDataChange will be callen in MainThread and hence you DatabaseClient.getInstance is running in MainThread.
    – musooff
    Nov 16 at 1:16
















It's not about AsyncTask but about Firebase. Firebase's onDataChange will be callen in MainThread and hence you DatabaseClient.getInstance is running in MainThread.
– musooff
Nov 16 at 1:16




It's not about AsyncTask but about Firebase. Firebase's onDataChange will be callen in MainThread and hence you DatabaseClient.getInstance is running in MainThread.
– musooff
Nov 16 at 1:16












1 Answer
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down vote



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It's not about AsyncTask but about Firebase. Firebase's onDataChange will be called in the MainThread and hence you DatabaseClient.getInstance is running in the MainThread.



You don't have to perform your Firebase calls in separate thread as Firebase client deals with it. But when you get a response from Firebase, it's onDataChange will be performed in the MainThread.



I suggest you to call Firebase in the MainThread and then after getting the data in onDataChanged, call your AsyncTask that has calls DatabaseClient.getInstance.






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    1 Answer
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    active

    oldest

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    1 Answer
    1






    active

    oldest

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    oldest

    votes






    active

    oldest

    votes








    up vote
    1
    down vote



    accepted










    It's not about AsyncTask but about Firebase. Firebase's onDataChange will be called in the MainThread and hence you DatabaseClient.getInstance is running in the MainThread.



    You don't have to perform your Firebase calls in separate thread as Firebase client deals with it. But when you get a response from Firebase, it's onDataChange will be performed in the MainThread.



    I suggest you to call Firebase in the MainThread and then after getting the data in onDataChanged, call your AsyncTask that has calls DatabaseClient.getInstance.






    share|improve this answer

























      up vote
      1
      down vote



      accepted










      It's not about AsyncTask but about Firebase. Firebase's onDataChange will be called in the MainThread and hence you DatabaseClient.getInstance is running in the MainThread.



      You don't have to perform your Firebase calls in separate thread as Firebase client deals with it. But when you get a response from Firebase, it's onDataChange will be performed in the MainThread.



      I suggest you to call Firebase in the MainThread and then after getting the data in onDataChanged, call your AsyncTask that has calls DatabaseClient.getInstance.






      share|improve this answer























        up vote
        1
        down vote



        accepted







        up vote
        1
        down vote



        accepted






        It's not about AsyncTask but about Firebase. Firebase's onDataChange will be called in the MainThread and hence you DatabaseClient.getInstance is running in the MainThread.



        You don't have to perform your Firebase calls in separate thread as Firebase client deals with it. But when you get a response from Firebase, it's onDataChange will be performed in the MainThread.



        I suggest you to call Firebase in the MainThread and then after getting the data in onDataChanged, call your AsyncTask that has calls DatabaseClient.getInstance.






        share|improve this answer












        It's not about AsyncTask but about Firebase. Firebase's onDataChange will be called in the MainThread and hence you DatabaseClient.getInstance is running in the MainThread.



        You don't have to perform your Firebase calls in separate thread as Firebase client deals with it. But when you get a response from Firebase, it's onDataChange will be performed in the MainThread.



        I suggest you to call Firebase in the MainThread and then after getting the data in onDataChanged, call your AsyncTask that has calls DatabaseClient.getInstance.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 16 at 1:19









        musooff

        15611




        15611






























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