如何异步过滤 Flux

Question

我需要检查该店铺的名称或该店铺的库存中是否包含子字符串。

 @Override
    public Flux<Shop> searchShopsBySearchingTextInShopsAndStocks(String searchText) {

// I received Flxux<List<Shop>> 
 return shopRepo.findAll().
   // next I check if substring in title of shop
   filter(shop -> {
         if (shop.getTitle().contains(searchText) || shop.getDescription().contains(searchText)) {
                                            
                       // if contains then return TRUE if not check in stocks
                        return true;
                    } else {
                                 // reeived all stock Flux<List<Stock>> of this shop and check
                          return stockService.findStocksByShopId(shop.getId()).
                                flatMap(stock -> {
                                    if (stock.getDescription().contains(searchText) || stock.getTitle().contains(searchText)) {

           // and in this place I need help

                                        return  // true
                                    }

                                    return //false 
                                });

          });
}

在检查stocks中的子字符串内容时，出现一次就足够了。

Answer 1

正在查看 Flux#filter 运营商签名：

Flux<T> filter(Predicate<? super T> p)

我们看到它接受一个简单的 Java 谓词作为参数。您不能在其中执行异步操作。

您可以改用 filterWhen 运算符：

shopRepo.findAll()  
    .filterWhen(shop ->
        (shop condition) ? Mono.just(true) :
                stockService.findStocksByShopId(shop.getId())
                        .map(stock -> (stock condition)))

如何异步过滤 Flux

How to filter Flux asynchronously

java

spring-webflux

project-reactor