Collect result from flatMap using Spring WebFlux - reactive-programming

Question

I have a interface Event which internally calls the checkEvent() of each implementation and gives EventResponse as object. So the final output using all implementation gives me List
As these are not synchronized, try to execute in async way to get the output fast.
I am trying to achieve the same thing using Spring Web Flux.
However not able to acheive the final result i.e.List
My event interface is like:
public interface IEventProvider {
EventResponse check(EventRequest request);
}
I have 3 implementation of this which are as below:
MumbaiEventProvider
import org.springframework.stereotype.Component;
#Component
public class MumbaiEventProvider implements IEventProvider {
#Override
public EventResponse check(EventRequest request) {
return EventResponse.builder().location("Mumbai").build();
}
}
DelhiEventProvider
import org.springframework.stereotype.Component;
#Component
public class DelhiEventProvider implements IEventProvider {
#Override
public EventResponse check(EventRequest request) {
return EventResponse.builder().location("Delhi").build();
}
}
ChennaiEventProvider
import org.springframework.stereotype.Component;
#Component
public class ChennaiEventProvider implements IEventProvider {
#Override
public EventResponse check(EventRequest request) {
return EventResponse.builder().location("Chennai").build();
}
}
I have tried using below code but not helping as final output is not as expected:
#Service
public class EventProviderHandler {
private final List<IEventProvider> providers;
#Autowired
public EligibilityHandler(List<IEventProvider> providers) {
this.providers = providers;
}
public Mono<ServerResponse> getEligibilities(ServerRequest request) {
List<EventResponse> eventList = new ArrayList<>();
Mono<EventRequest> eventRequestMono = request.bodyToMono(EventRequest.class);
List<EventResponse> events = Flux.fromIterable(providers).parallel().flatMap(eventProvider -> {
eventList.add(eventProvider.check(eventRequestMono));
return eventList;
}).collectList();
}
}
What is expected is to return:
List<EligibilityResponse> eligibilities = Flux.fromIterable(providers).parallel().flatMap(eligibilityProvider -> {
eligibilities.add(eligibilityProvider.check(eligibilityRequestMono));
return eligibilities;
})