private class MyFilter extends Filter {

    @Override
    protected FilterResults performFiltering(CharSequence constraint) {
        final FilterResults results = new FilterResults();

        if (constraint == null || constraint.length() == 0) {
            final ArrayList<MyObject> list;
            synchronized (adapter) {
                list = new ArrayList<>(allObjects);
            }
            results.values = list;
            results.count = list.size();
        } else {
            final String prefixString = constraint.toString().toLowerCase();

            final ArrayList<MyObject> values;
            synchronized (adapter) {
                values = new ArrayList<>(allObjects);
            }

            final int count = values.size();
            final ArrayList<MyObject> newValues = new ArrayList<>();

            for (int i = 0; i < count; i++) {
                final MyObject value = values.get(i);
                final String valueText = value.firstName.toLowerCase() + " " + value.lastName.toLowerCase();
                Log.i("search", valueText);
                if (valueText.contains(prefixString)) {
                    newValues.add(value);
                    Log.i("search", "in");
                }
            }
            results.values = newValues;
            results.count = newValues.size();
        }
        return results;
    }

    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
        adapter.students = (List<MyObject>) results.values;
        if (results.count > 0) {
            adapter.notifyDataSetChanged();
        } else {
            adapter.notifyDataSetInvalidated();
        }
    }
}

@Override
public Filter getFilter(){
    return new MyFilter();
}

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
    @Override
    public boolean onQueryTextSubmit(String query) {
        adapter.getFilter().filter(query);
        return false;
    }

    @Override
    public boolean onQueryTextChange(String query) {
        adapter.getFilter().filter(query);
        return false;
    }
});