How to implement realtime search using firestore

Question

If (searchView != null) {
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return true;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                Log.d(TAG, "search changed to: " + newText.toString());
                Query query;
                if (newText.toString().isEmpty()) {
                    query = db.collection("milk");
                } else {
                    String newText1 = newText.substring(0,1).toUpperCase();
                    newText=newText1+newText.substring(1);
                    Log.d("query",newText);

I am using if statements to pass on or check in other queries as well but these conditions aren't working as per log statements.

                    if (newText != "") {
                        query = db.collection("vegetables").whereEqualTo("productName", newText.toString());
                        FirestoreRecyclerOptions<horizontalProductModel> options = new FirestoreRecyclerOptions.Builder<horizontalProductModel>()
                                .setQuery(query, horizontalProductModel.class)
                                .build();
                        adapter.updateOptions(options);
                        Log.d("vg", String.valueOf(query.get()));
                        Log.d("vg", String.valueOf(options.getSnapshots().isEmpty()));

Log doesn't proceed as options is always not null but it returns a recyclier view so how can I check for other conditions.

                        if (options == null) {
                            query = db.collection("dailyNeeds").whereEqualTo("productName", newText.toString());

                            FirestoreRecyclerOptions<horizontalProductModel> options1 = new FirestoreRecyclerOptions.Builder<horizontalProductModel>()
                                    .setQuery(query, horizontalProductModel.class)
                                    .build();
                            adapter.updateOptions(options1);
                            Log.d("dN", String.valueOf(options));
                            if (options1 == null) {
                                query = db.collection("milk").whereEqualTo("productName", newText.toString());
                                FirestoreRecyclerOptions<horizontalProductModel> options2 = new FirestoreRecyclerOptions.Builder<horizontalProductModel>()
                                        .setQuery(query, horizontalProductModel.class)
                                        .build();
                                adapter.updateOptions(options2);
                                Log.d("mk", String.valueOf(options));
                            }
                        }
                    }
                }

                return false;
            }
        });

    }

}

is there any other way other than this or merge two or more query results and pass it to Firebase UI.