ArrayAdapter with custom view using anonymous class

CustomArrayAdapter.java

periodsAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, new String[]{"loading..."}) {
            View render(View convertView, int position) {
                if (convertView == null) {
                    convertView = getLayoutInflater().inflate(R.layout.single_month, null);
                }

                // TODO set some data to views
                return convertView;
            }

            @Override
            public View getDropDownView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
                return render(convertView, position);
            }

            @NonNull
            @Override
            public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
                return render(convertView, position);
            }

            @Nullable
            @Override
            public String getItem(int position) {
                return dataSource.get(position);
            }
        };

Assuming that the data is being loaded from as server.

All you need here is to override getDropDownView and getView.

you can even got as far as showing different views