如何用mono映射通量?

我有两个请求:

Flux<ProductID> getProductIds() {
    return this.webClient.get()
            .uri(PRODUCT_ID_URI)
            .accept(MediaType.APPLICATION_STREAM_JSON)
            .retrieve()
            .bodyToFlux(ProductID.class);
}

Mono<Product> getProduct(String id) {
    return this.itemServiceWebClient.get()
            .uri(uriBuilder -> uriBuilder.path(PRODUCT_URI + "/{id}")
                    .build(id))
            .accept(MediaType.APPLICATION_STREAM_JSON)
            .exchange()
            .flatMap(clientResponse -> clientResponse.bodyToMono(Product.class));
}

Flux<Product> getProducts() {
    return Flux.create(sink -> this.gateway.getProductIds()
            .doOnComplete(() -> {
                log.info("PRODUCTS COMPLETE");

                sink.complete();
            })
            .flatMap(productId -> this.getProduct(productId.getID()))
            .subscribe(product -> {
                log.info("NEW PRODUCT: " + product);

                sink.next(product);
            }));
}

当我调用此函数时,会得到以下输出:

PRODUCTS COMPLETE
NEW PRODUCT: ...
NEW PRODUCT: ...
....

当然,流在结果出现之前就关闭了,因为异步mono映射。如何保持这种非阻塞状态,同时确保在调用on complete之前得到结果?