How to get list of documents from a collection in Firestore Android

Question

My structure of Firestore database:

|
|=>root_collection
                  |
                  |=>doc1
                         |                  
            


        

Answer 1

To have a list that contains all the name of your documents within the root_collection, please use the following code:

firestore.collection("root_collection").get().addOnCompleteListener(new OnCompleteListener() {
    @Override
    public void onComplete(@NonNull Task task) {
        if (task.isSuccessful()) {
            List list = new ArrayList<>();
            for (QueryDocumentSnapshot document : task.getResult()) {
                list.add(document.getId());
            }
            Log.d(TAG, list.toString());
        } else {
            Log.d(TAG, "Error getting documents: ", task.getException());
        }
    }
});

The result in your logcat will be:

[doc1, doc2, doc3]

Remember, this code will work, only if you'll have some properties within those documents, otherwise you'll end ut with an empty list.