Spring Webflux - How to aggregate three Flux objects into 1 using Tuple3

I am trying to aggregate 3 Flux objects into 1 using Tuple3
However, I am still stuck. I searched online and saw that you can use Mono.zip() but that doesn't apply to Flux.

public class OrderService {

	private final AppWebClient appWebClient;

	public Mono<OrderDetailsAggregate> getAggregatedOrderDetails(List<String> orderNoList1,
			List<String> orderNoList2, List<String> orderNoList3) {
		Flux<Map<String, List<String>>> fluxOne = this.appWebClient.getFluxOne(orderNoList1);
		Flux<Map<String, String>> fluxTwo = this.appWebClient.getFluxTwo(orderNoList2);
		Flux<Map<String, List<String>>> fluxThree = this.appWebClient.getFluxThree(orderNoList3);

		return Mono.zip(fluxOne, fluxTwo, fluxThree).map(this::combine); //error here
	}

	private OrderDetailsAggregate combine(
			Tuple3< Flux<Map<String, List<String>>>, Flux<Map<String, String>>, Flux<Map<String, List<String>>> > tuple) {
		return OrderDetailsAggregate.create(tuple.getT1(), tuple.getT2(), tuple.getT3()); 
	}

}

fluxOne, fluxTwo, fluxThree have different data types.

OrderDetailsAggregate class

@Data
@ToString
@AllArgsConstructor(staticName = "create")
public class OrderDetailsAggregate {

	private Flux<Map<String, List<String>>>  fluxOne;
	private Flux<Map<String, String>> fluxTwo;
	private Flux<Map<String, List<String>>> fluxThree;
}

How do I combine them?

Thank you.

If you need to return Mono<OrderDetailsAggregate> from getAggregatedOrderDetails method, then why not just create Mono object without zip:

public Mono<OrderDetailsAggregate> getAggregatedOrderDetails(List<String> orderNoList1,
                                                                 List<String> orderNoList2, List<String> orderNoList3) {
        Flux<Map<String, List<String>>> fluxOne = this.appWebClient.getFluxOne(orderNoList1);
        Flux<Map<String, String>> fluxTwo = this.appWebClient.getFluxTwo(orderNoList2);
        Flux<Map<String, List<String>>> fluxThree = this.appWebClient.getFluxThree(orderNoList3);
        OrderDetailsAggregate aggregate = OrderDetailsAggregate.create(fluxOne, fluxTwo, fluxThree);
        return Mono.just(aggregate);
    }

To me it looks like you are treating the Flux'es your appWebClient is returning as if they were Mono's.

I assume, you want to have all values of the fluxes in your OrderDetailsAggregate. Should that be the case, I would suggest to collect the Flux into a Mono, do a Mono.zip to get a tuple and map that to your OrderDetailsAggregate:

public Mono<OrderDetailsAggregate> getAggregatedOrderDetails(List<String> orderNoList1,
            List<String> orderNoList2, List<String> orderNoList3) {
        Mono<Map<String, List<String>>> monoOne = this.appWebClient.getFluxOne(orderNoList1).collect(HashMap::new, Map::putAll);
        Mono<Map<String, String>> monoTwo = this.appWebClient.getFluxTwo(orderNoList2).collect(HashMap::new, Map::putAll);
        Mono<Map<String, List<String>>> monoThree = this.appWebClient.getFluxThree(orderNoList3).collect(HashMap::new, Map::putAll);

        return Mono.zip(monoOne, monoTwo, monoThree).map(tuple -> OrderDetailsAggregate.create(tuple.getT1(), tuple.getT2(), tuple.getT3()));
}

Should you just care about one value from the flux, then you can replace the collect() with next().

Edit: I see you are passing Flux to your create() method. So this answer only applies if you would change that as well. If your OrderDetailsAggregate is a Dto and not a service, then it would perhaps be a good idea to not have that flux logic in there but rather do it in the getAggregatedOrderDetails method.