tinmegali
5/21/2018 - 6:54 AM

Java - Mapping 2 layers/levels Collections to Collection

Mapping a 2 layers collection level Set<Set<T>> to a 1 level collection Set<T>

Set<T> entity = list.stream()
\!h  .flatMap(ent -> ent.getItens().stream())
  .collect(Collectors.toSet());

Take into consideration that:

  • ent.getItens() returns a Set<T>