Spring Data Cassandra Pagination - spring-boot

Question

Can anybody know how to achieve the pagination in Spring Data Cassandra ?
I have tried all the possible alternatives to implement pagination for my table.
One of the stackoverflow answers says it is not provided directly.
Paging SELECT query results from Cassandra in Spring Boot application
As per documentation (https://docs.spring.io/spring-data/cassandra/docs/current-SNAPSHOT/reference/html/#cassandra.repositories.queries) says CrudRepository provides method with Pageable.
org.springframework.data.repository.CrudRepository does not provide.
I am using Cassandra 3.11.3 and Spring Boot 1.5.1.RELEASE.
Can one provide me simple pagination demo with Spring Data Cassandra ?

Answer 1

The pagination in Spring Data Cassandra work in 'forward only' basis like the way iterable interface works.
#Autowired
PersonRepository personrepo;
#GetMapping("/all/{page}")
public List<Person> getPaginated(#PathVariable Integer page) {
int currpage = 0, size = 2;
Slice<Person> slice = personrepo.findAll(CassandraPageRequest.first(size));
while(slice.hasNext() && currpage < page) {
slice = personrepo.findAll(slice.nextPageable());
currpage++;
}
return slice.getContent();
}
Where your repository contains:
public interface PersonRepo extends CrudRepository<Person, Integer> {
Slice<Person> findAll(Pageable pr);
}
Hence, you keep querying the result until the desired location of the data is reached.

Answer 2

This is the simplest way to do pagination in reactive Cassandra or regular Cassandra with spring data
In your repository class create custom methods with Query annotation (key point here is for second method there should be a offset that needs to sent as a parameter) Assuming date created is a clustering key
user table primary key(user_id, date_created)
Ex:-
#Query("select * from user order by date_created asc Limit :count)
Flux<UserEntity> findFirstSetOfUsers(#Param(count) int noOfRecords);
Next set of records
#Query("select * from user where date_created > :dateCreated order by date_created asc Limit :count)
Flux<UserEntity> findNextSetOfUsers(#Param(count) int noOfRecords, #Param(dateCreated) Date dateCreated);