Call paginated REST request in spring boot

Question

I'm building a spring boot application that needs to make REST call which has pagination implemented, like:

where p is page number & ps is page size.

The result of this api apart from output list also displays paging info like:

"paging": {
        "pageIndex": 1,
        "pageSize": 100,
        "total": 372
    }

Currently, in my first hit I'm retrieving the output list and also reading this paging info and then calculating how many further hits are required. In above case, 372 / 100 = 3, then 3 - 1, because one hit is already done.

But this is very naive approach. Is there something that spring / java provides, that I can use?

Please suggest.

Thanks

It has nothing naive. It just use simple (but incorrect) arithmetics. If there are 372 elements, and the page size is 100, you need to make a total of 4 requests, not 3: one for elements 1 to 100, one for elements 101 to 200, one for elements 201 to 300, and one for elements 301 to 372. — JB Nizet, Jan 24 '20 at 08:29
@JBNizet, yes I meant that only, just am more focused on if there is other cleaner solution. — reiley, Jan 24 '20 at 08:32
Graphql alternative :https://graphql.org/learn/pagination/ it will gives your more felxibility what do you want to load — Rebai Ahmed, Jan 24 '20 at 10:01
There are several alternative approaches here https://stackoverflow.com/questions/34647303/spring-resttemplate-with-paginated-api — Shafiul, Jan 24 '20 at 10:25

score 0 · Answer 1 · answered Jan 24 '20 at 12:54

@reiley Implement Paging using Pageable interface.

It gives other detail also so it become helpful to perform other action.

Front end page size start from 1 and backend it start from 0.

Controller :

@GetMapping("/")
  private ResponseEntity<Page<User>> getUsers(@RequestParam(value = "page_no", defaultValue = "1") Integer pageNo,
                                              @RequestParam(value = "limit", defaultValue = "10") Integer limit,
                                              @RequestParam(value = "order_by", defaultValue = "userId") String sortBy,
                                              @RequestParam(value = "order_type", defaultValue = "asc") String orderBy) {
    Page<UserDTO> users = userService.getUsers(pageNo, limit, sortBy, orderBy);
    return customResponse(true, Constants.DATA_FETCH, ENTITY_NAME.concat("s"), users);
  }

ServiceImpl

@Override
  public Page<UserDTO> getUsers(Integer pageNo, Integer limit, String sortBy, String orderBy) {

    Sort sortingInOrder = Util.sortingOrder(orderBy, sortBy);
    Pageable pageable = PageRequest.of(pageNo - 1, limit, sortingInOrder);
    Page<UserDTO> result = userRepository.findAll(pageable).map(user -> userMapper.toDTO(user));
    if (result.getContent().size() > 0) {
      return result;
    }
    return Page.empty();
  }

Util

public static Sort sortingOrder(String orderBy, String sortBy) {
    Sort sortingInOrder;
    switch (orderBy) {
      case "asc":
        sortingInOrder = Sort.by(sortBy).ascending();
        break;
      case  "desc" :
        sortingInOrder = Sort.by(sortBy).descending();
        break;
      default:
        throw new CustomException("Invalid Input in order by!!!");
    }
    return sortingInOrder;
  }

Call paginated REST request in spring boot

1 Answers1

Controller :

ServiceImpl

Util