spring delete objest from database that are not in your object list

1Optional<Order> orderFromDb = orderRepo.findById(id);
2
3    if(CollectionUtils.isNotEmpty(orderRequest.getItems()))
4
5    {
6        // if there are less items in update request than database
7        if (orderRequest.getItems().size() < orderFromDb.getItems().size()) {
8            Set<Long> itemIds = orderRequest.getItems().stream().map(id -> id.getId()).collect(Collectors.toSet());
9            for (ItemRequest itemRequest : orderRequest.getItems()) {
10                Iterator<Item> item = orderFromDb.getItems().iterator();
11                Item i;
12                while (item.hasNext()) {
13                    i = item.next();
14                    if (!itemIds.contains(i.getId())) {
15                        item.remove();
16                        continue;
17                    }
18                    if (i.getId() == itemRequest.getId()) {
19                        i.setName(itemRequest.getName());
20                    }
21                }
22            }
23        } else {
24            // if there are more or same items in update request and database
25            for (ItemRequest itemRequest : orderRequest.getItems()) {
26                // assuming for newly added items id will not be there(db should generate)
27                if (itemRequest.getId() == null) {
28                    Item item = new Item();
29                    item.setName(itemRequest.getName());
30                    item.setOrder(orderFromDb);
31                    orderFromDb.getItems().add(item);
32                    continue;
33                }
34                for (Item item : orderFromDb.getItems()) {
35                    if (item.getId() == itemRequest.getId()) {
36                        item.setName(request.getName());
37                    }
38                }
39            }
40        }
41    }
42