How to access array data from Firebase Firestore?

Question

I have a Firebase Firestore database that looks like this:

And I want to store that data in my ArrayList<>

If You are not understanding anything you can check my previous question Question Link StackOverFlow

So you want to get the content of the `favFoods` array right? Then please show a more detailed database schema and what have you tried so far. — Alex Mamo, Aug 25 '21 at 08:13
@AlexMamo did you check my previous question because I am asking related to that [question link](https://stackoverflow.com/q/68916796/16525859) — Tony Stark, Aug 25 '21 at 08:16
Is this `db.collection("data").document("one")` your structure? — Alex Mamo, Aug 25 '21 at 08:17
Yes!. it looks like this `db.collection("fav").document("randomId")` — Tony Stark, Aug 25 '21 at 08:21
Do you have that `randomId` stored in a variable? Then show us what have you tried so far. — Alex Mamo, Aug 25 '21 at 08:23
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/236384/discussion-between-tony-stark-and-alex-mamo). — Tony Stark, Aug 25 '21 at 08:25
And how would you access that document if you [don't have its ID](https://stackoverflow.com/questions/68916648/is-there-a-way-to-access-the-auto-generate-document-id-from-firestore/68918829#68918829)? — Alex Mamo, Aug 25 '21 at 08:43
No! I have the Id that looks like this `xQjHVBm0GtUE4VhP3A6m` randomly — Tony Stark, Aug 25 '21 at 09:07

score 2 · Accepted Answer · answered Aug 25 '21 at 09:23

To display the of your favFoods array, please use the following lines of code:

db.collection("fav").document("xQjHVBm0GtUE4VhP3A6m").get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
        if (task.isSuccessful()) {
            DocumentSnapshot document = task.getResult();
            if (document.exists()) {
                List<String> favFoods = (List<String>) document.get("favFoods");
                for (String favFood : favFoods) {
                    Log.d(TAG, favFood);
                }
            } else {
                Log.d(TAG, "No such document");
            }
        } else {
            Log.d(TAG, "get failed with ", task.getException());
        }
    }
});

So as you can see, you should call get() and cast the object to List. The result in the logcat will be:

Chicken
Humburger
vegetables

How to access array data from Firebase Firestore?

1 Answers1