ListPushVO pushVOList1 = pushListstream collectCollectorsgroupingByPushgetModule entrySet stream mapentry - PushVObuilder

List pushVOList1 = pushList.stream() .collect(Collectors.groupingBy(Push::getModule)) .entrySet() .stream() .map(entry -> new PushVO(entry.getKey(), PushConverter.INSTANCE.toPushDTO(entry.getValue()))) .collect(Collectors.toList());