Dmitry Roo

public List<Receipt> buildTitle(List<ComServiceResponse> comServiceResponses) {
return comServiceResponses.stream()
 .map(ComServiceResponse::getComment)
 .map(Comment::getComs)
 .filter(Objects::nonNull)
 .flatMap(List::stream) // Collection::stream ?
 .map(comService -> {   // todo:: extract to mapping method
                var date = calendarService.formatDate(comService.getPeriod()); // todo :: check for null here and below

                var paymentStatus = isPayed(comService.getComment().getComs()); 
                var totalAmount = calculateComServiceTotalAmount(comService.getComment().getComs());

                var receipt = new Receipt();  // todo:: beter use fluent accessors or builder

                receipt.setPeriod(date);
                receipt.setPayed(paymentStatus);
                receipt.setTotalAmount(totalAmount);
                receipt.setAccount(comService.getAccount());
                receipt.setServiceIcon(properties.getMyVillageIcon());
                receipt.setName(comService.getComment().getComs().get(0).getOwner());
                receipt.setAddress(comService.getComment().getComs().get(0).getAddress());
                
                return receipt;
 })
 .toList();
}

var dateString = "202208";
        var inFormat = new SimpleDateFormat("yyyyMM");
        var date = inFormat.parse(dateString);
        System.out.println(date);  // Mon Aug 01 00:00:00 MSK 2022

        var outFormat = new SimpleDateFormat("yyyy MMMM");
        var dateFormatSymbols = new DateFormatSymbols();
        dateFormatSymbols.setMonths(new String[]{"Папа", "у", "Вити", "силен", "в", "джаве.", "Работает", "Август", "папа", "за", "Витю", "весь", "год"});
        outFormat.setDateFormatSymbols(dateFormatSymbols);
        System.out.println(outFormat.format(date)); // 2022 Август