How to read data from Firebase ONCE using java/android?

Question

I\'m trying to use the Java API to read data from a Firebase database in an Android application in the onCreate() event. In other words, I\'m trying to do the simplest read

Answer 1

That is the right method, and you're on the right track. The naming is just a little confusing (sorry!). If you do the addListenerForSingleValueEvent, your overridden onDataChange method will be called exactly once, with a DataSnapshot, just as you wish (and just like "ref.once('value' ...)" would do).

So you should be able to do:

// Add all polls in ref as rows
polls.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot snapshot) {
        for (DataSnapshot child : snapshot.getChildren()) {
            ...
        }
    }
}