How can i save data retrieved from firebase into arraylist

Asked Mar 30 '21 at 15:14

Active Mar 30 '21 at 15:56

Viewed 27 times

this is the code i am using but the data cannot be accessed out the datasnapshot and the data is been successfully retrieved which i can view in my logcat ,but it just does not get added in Arraylist ##```try {

        mbase = FirebaseDatabase.getInstance().getReference("/information/" + y2+"/"+c2+"/"+s2+"/");
        mbase.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                for (DataSnapshot ds : snapshot.getChildren()) {
                    String key = ds.getKey();
                    mySubject.add(key);
                    //Log.i("SubjectNo", key);
                }
            }
            @Override
            public void onCancelled(@NonNull DatabaseError error) {
            }
        });
    }catch (Exception e){
        e.printStackTrace();```

edited Mar 30 '21 at 15:21

asked Mar 30 '21 at 15:14

PRATIK DHARGALKAR

Why do you say it is not added to the "mySubject" ArrayList? How do you check that? – Alex Mamo Mar 30 '21 at 15:31
i logged that String key and its retrieving the data, but when i access the arraylist out side datasnap shot for (int i = 0; i – PRATIK DHARGALKAR Mar 30 '21 at 15:49
You cannot simply use the `mySubject` ArrayList outside the callback. Firebase API is asynchronous. So please check the duplicate to see how can you solve this using a custom callback. – Alex Mamo Mar 30 '21 at 15:57
you mean the duplicate questions like this ones? – PRATIK DHARGALKAR Mar 30 '21 at 16:01
1

thanks @AlexMamo what i will do is put all the code that needs to access those values inside the data snapshot then i think i should be fine – PRATIK DHARGALKAR Mar 30 '21 at 16:17

How can i save data retrieved from firebase into arraylist

this is the code i am using but the data cannot be accessed out the datasnapshot and the data is been successfully retrieved which i can view in my logcat ,but it just does not get added in Arraylist ##```try {

0 Answers0