List<Object>를 List<Long>로 변환

List<Object> currentChargerList;

List<Object> prevChargerList;

List<Long> currChargerUserSeqs = currentChargerList.stream().map(e -> e.getComUserMngt().getUserMngtSeq()).collect(Collectors.toCollection(ArrayList::new));

List<Long> prevChargerUserSeqs = prevChargerList.stream().map(e -> e.getComUserMngt().getUserMngtSeq()).collect(Collectors.toCollection(ArrayList::new));