Improvement with list stream HashMap

Question

Is there a way of improving this method using list stream.

@Override
public HashMap<Long, Long> countSearchBetweenDates(OffsetDateTime startPeriod, OffsetDateTime endPeriod) {
    List<Tuple> results = this.repository.countBetweenDate(startPeriod, endPeriod);
    HashMap<Long,Long> companyCountMap = new HashMap<>();
    for(Tuple t : results){
        companyCountMap.put(t.get(0,Long.class), t.get(1, Long.class));
    }
    return companyCountMap;
}

I've tried it but I just can't get it to work because of the lambda operator.

 return results.stream().collect(Collectors.toMap(Tuple::get(0, Long.class), Tuple::get(1, Long.class));

The Tuple::get(0, Long.class), Tuple::get(1, Long.class) gets signaled as an error but IDE can't identify what is it.

Answer 1

The syntax you are using is not correct, the correct one should be :

return results.stream()
        .collect(Collectors.toMap(t -> t.get(0, Long.class), t -> t.get(1, Long.class));