Update RecyclerView Adapter after data is loaded from the server

So, I am trying to load some data from my local server to my Listview. My Fragment's onCreateView has:

myAdapter = new myRecyclerViewAdapter(Products.ITEMS, mListener);

In my Products Class, I have:

static {
   loadItems(0);
}

public static void addItem(Product item) {
    ITEMS.add(item);
    ITEM_MAP.put(item.id, item);
}

public static void loadItems(int start){
    Log.d(TAG, String.valueOf(ITEMS.size()));
    ProductsService.fetchAll(start, new ServiceListCallback() {
        @Override
        public void onDone(ArrayList baseModelList) {
            Log.d(TAG,"Done");
            Iterator<Product> iterator = baseModelList.iterator();
            while (iterator.hasNext()) {
                addItem(iterator.next());
            }
        }
    });



}

ProductService has:

 public static ArrayList<Product> fetchAll(int start, final ServiceListCallback serviceListCallback){
    productList = new ArrayList<Product>();

    HttpAgent.get("http://192.168.0.100/products")
            .goJsonArray(new JsonArrayCallback() {
                @Override
                protected void onDone(boolean success, JSONArray jsonArray) {
                    //Log.d(TAG, String.valueOf(success));

                    if(success){
                        for(int i = 0; i < jsonArray.length() ; i++){
                           JSONObject jsonObject = jsonArray.optJSONObject(i);
                            Product singleProduct = new Product(
                                    jsonObject.optString("id"),
                                    jsonObject.optString("title"),
                                    jsonObject.optString("details"),
                                    jsonObject.optString("description"),
                                    jsonObject.optDouble("price"),
                                    jsonObject.optString("thumbnail")

                            );
                            productList.add(singleProduct);

                        }
                        Log.d(TAG, String.valueOf(productList.size()));



                    }

                    serviceListCallback.onDone(productList);
                }
            });


    return productList;
}

The flow works perfectly but the listview is not updated. I know that I am supposed to call myAdapter.notifyItemInserted(Products.ITEMS.size()); But I cant get the myAdapter instance from the callback. Whats the work around? I am still new to java and android, so code improvements are highly appreciated.