How to upload array to Firestore Data in Android Studio Java

Question

I want to upload data like this:

Edited Questions

//I have ArrayList<FoodModel> arr;
ArrayList<FoodModel> arr = new ArrayList<>();
arr.add(new FoodModel("Hamburger"));
arr.add(new FoodModel("Pizza"));
arr.add(new FoodModel("Chicken"));
//and so on...

I want to upload that ArrayList to firestore it is Possible?

Answer 1

You just need add a list field in the hashmap:

Map<String, Object> docData = new HashMap<>();
docData.put("favFoods", Arrays.asList("Hamburger", "Vegetables"));

db.collection("data").document("one")
        .set(docData)
        .addOnSuccessListener(new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void aVoid) {
                Log.d(TAG, "DocumentSnapshot successfully written!");
            }
        })
        .addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                Log.w(TAG, "Error writing document", e);
            }
        });

Alternatively, you can also use arrayUnion to add new items to an array.

DocumentReference docRef = db.collection("col").document("docId");
docRef.update("favFoods", FieldValue.arrayUnion("Pizza"));

---

You can add array of objects (and even nested maps) in Firestore. However, you should add the array as a list.

References:

• Cloud Firestore Data Types

• Update elements in an array