I have implemented the following example:
Map<String, List<Event>> map = events.getItems().stream()
.collect(Collectors.groupingBy(Event::getStatus, Collectors.toList()));
How can I get an output of Map<String, List<EventDto>> map instead?
An EventDto can be obtained by executing an external method which converts an Event to an EventDto. For example - this::convertFromEventToEventDto.
You need a mapping Collector to map the Event elements to EventDto elements :
Map<String, List<EventDto>> map =
events.getItems()
.stream()
.collect(Collectors.groupingBy(Event::getStatus,
Collectors.mapping(this::convertFromEventToEventDto,
Collectors.toList())));