DATACASS-56 - Cassandra paging support.

[mp911de]

We now support forward-only paging with Cassandra through the Template API and repositories. Results in Cassandra are paged by navigating forward-only through pages described by a binary paging state encapsulated by CassandraPageRequest and accessible via the returned Slice. Spring Data Page's do not fit to Cassandra's paging concept because Cassandra paging is not based on limit/offset.

Page requests are applicable to a Query and as a parameter of query methods.

Query query = Query.empty().pageRequest(CassandraPageRequest.first(10));
Slice<User> slice = template.slice(query, User.class);

do {

// consume slice

if (slice.hasNext()) {
slice = template.select(query, slice.nextPageable(), User.class);
} else {
break;
}
} while (!slice.getContent().isEmpty());

assertThat(ids).hasSize(100);
assertThat(iterations).isEqualTo(10);

interface UserRepository implements Repository<User, String> {

Slice<User> findAllByName(String name, Pageable pageRequest);
}

---

Related ticket: DATACASS-56.

[jxblum]

Reviewed, polished and merged to master for Spring Data Kay GA.

[lukasz-gosiewski]

@mp911de
Hello,
Could you please explain why above code checks if slice content is not empty in every loop?
I'm now implementing something similar and when I'm fetching results from DB with pageSize set to a total amount of results in DB I'm getting two pages instead of one, and one of them is empty. Is this proper behavior?

[mp911de]

Stores can return empty results but it's possible that the paging is not finished yet.

In general, please file a ticket or ask questions on StackOverflow as closed pull requests are not a good place for discussions.

[mustafin]

@mp911de How to make it work with reactive repo? Not working with Flux<T>, return all results.
Mono<Slice<T>> yields IncorrectResultSizeDataAccessException

[mp911de]

Please upgrade to at least 2.1RC1, see DATACASS-529.

[mgezkaya]

Hi all I have written a code block to use pagination with user action here is my code I hope it helps you well.
https://gist.github.com/mgezkaya/f90e19e8e86e35cabcf22bd97325cf3a