Return ldap entries on paginated form in springboot

Question

I have a ldap method that returns all users that are in it (almost 1300 users) and I want to return them by page, similar to what PagingAndSortingRepository does in Springboot:

If I have this endpoint ( users/?page=0&size=1 )and I wnat to return on page 0 just 1 entry.

Is there any way to do that?

Currently I have this but it doesn´t work:

SearchRequest searchRequest = new SearchRequest(ldapConfig.getBaseDn(), SearchScope.SUB,
                Filter.createEqualityFilter("objectClass", "person"));
        ASN1OctetString resumeCookie = null;
        while (true) {
            searchRequest.setControls(new SimplePagedResultsControl(pageable.getPageSize(), resumeCookie));
            SearchResult searchResult = ldapConnection.search(searchRequest);
            numSearches++;
            totalEntriesReturned += searchResult.getEntryCount();
            for (SearchResultEntry e : searchResult.getSearchEntries()) {

                 String[] completeDN = UaaUtils.searchCnInDn(e.getDN());
                 String[] username = completeDN[0].split("=");
                 UserEntity u = new UserEntity(username[1]);
                 list.add(u);

                System.out.println("TESTE");
            }

            SimplePagedResultsControl responseControl = SimplePagedResultsControl.get(searchResult);
            if (responseControl.moreResultsToReturn()) {
                // The resume cookie can be included in the simple paged results
                // control included in the next search to get the next page of results.
                System.out.println("Antes "+resumeCookie);
                resumeCookie = responseControl.getCookie();
                System.out.println("Depois "+resumeCookie);
            } else {
                break;
            }

            Page<UserEntity> newPage = new PageImpl<>(list, pageable, totalEntriesReturned);

            System.out.println("content " + newPage.getContent());
            System.out.println("total elements " + newPage.getTotalElements());

            System.out.println(totalEntriesReturned);
        }

score 1 · Answer 1 · answered Mar 29 '19 at 14:54

I'm unsure if this is the proper way, but here's how I went about it:

public PaginatedLookup getAll(String page, String perPage) {
  PagedResultsCookie cookie = null;
  List<LdapUser> results;

  try {
      if ( page != null ) {
          cookie = new PagedResultsCookie(Hex.decode(page));
      } // end if

      Integer pageSize = perPage != null ? Integer.parseInt(perPage) : PROCESSOR_PAGE_SIZE;

      PagedResultsDirContextProcessor processor = new PagedResultsDirContextProcessor(pageSize, cookie);
      LdapName base = LdapUtils.emptyLdapName();

      SearchControls sc = new SearchControls();
      sc.setSearchScope(SearchControls.SUBTREE_SCOPE);
      sc.setTimeLimit(THREE_SECONDS);
      sc.setCountLimit(pageSize);
      sc.setReturningAttributes(new String[]{"cn", "title"});

      results = ldapTemplate.search(base, filter.encode(), sc, new PersonAttributesMapper(), processor);

      cookie = processor.getCookie();
  } catch ( Exception e ) {
      log.error(e.getMessage());
      return null;
  } // end try-catch

  String nextPage = null;

  if ( cookie != null && cookie.getCookie() != null ) {
      nextPage = new String(Hex.encode(cookie.getCookie()));
  } // end if
  return new PaginatedLookup(nextPage, results);
}

The main issue I kept on hitting was trying to get the cookie as something that could be sent to the client, which is where my Hex.decode and Hex.encode came in handy. PersonAttributesMapper is a private mapper that I have to make the fields more human readable, and PaginatedLookup is a custom class I use for API responses.

This is a decent solution. Some notes: be sure to provide a filter implementation, the code above lacks that, and the remote ldap server needs to have the feature enabled and supported. You could get an ldap error 53, unwilling to perform operation, or a similar error if the ldap target doesn't support this. Note too, that paginated search result sets increases storage requirements for the directory server. — J E Carter II, Feb 03 '21 at 20:32

Return ldap entries on paginated form in springboot

1 Answers1