在Spring Webflux中返回多个单声道

Question

我正在尝试使用SpringBoot2.0和新的reactive webFlux库。我想知道如何将通过无阻塞WebClient进行的两个调用的结果返回给我的Springboot API的调用者。我的代码是：

@RequestMapping("/search")
public CombinedResults perfomSearch(@RequestParam final String searchTerm) {
    Mono<SearchResponse> fasMono = searchService.getSearchResults(searchTerm, "fh");
    Mono<SearchResponse> esMono = searchService.getSearchResults(searchTerm, "es");
    CombinedResults combinedResults = new CombinedResults(fasMono, esMono);
    return combinedResults;

}

public class CombinedResults {

private Mono<SearchResponse> fasSearchResponse;

private Mono<SearchResponse> esSearchResponse;

public CombinedResults(final Mono<SearchResponse> fasSearchResponse, final Mono<SearchResponse> esSearchResponse) {
    this.fasSearchResponse = fasSearchResponse;
    this.esSearchResponse = esSearchResponse;
}

public Mono<SearchResponse> getFasSearchResponse() {
    return fasSearchResponse;
}

public void setFasSearchResponse(final Mono<SearchResponse> fasSearchResponse) {
    this.fasSearchResponse = fasSearchResponse;
}

public Mono<SearchResponse> getEsSearchResponse() {
    return esSearchResponse;
}

public void setEsSearchResponse(final Mono<SearchResponse> esSearchResponse) {
    this.esSearchResponse = esSearchResponse;
}

然而，如果我这样称呼它，我得到的回应是

{
  "fasSearchResponse": {
    "scanAvailable": true
  },
  "esSearchResponse": {
    "scanAvailable": true
  }
}

而不是SearchResponse对象的内容。我觉得我可能错过了一个基本的点，这是如何工作的！我的想法是，因为WebClient没有阻塞，所以我可以向web服务发出两个调用，然后将它们组合起来，而不需要完全的未来等等？

Answer 1

我认为您应该返回一个对象的Mono，该对象表示由该操作响应的模型。假设combinedresults是您的模型。这个类应该类似于：

public class CombinedResults {

    private SearchResponse fasSearchResponse;

    private SearchResponse esSearchResponse;

    public CombinedResults(final SearchResponse fasSearchResponse, final SearchResponse esSearchResponse) {
        this.fasSearchResponse = fasSearchResponse;
        this.esSearchResponse = esSearchResponse;
    }

    //... getters AND/OR setters
}

在控制器上执行如下操作：

@RequestMapping("/search")
public Mono<CombinedResults> perfomSearch(@RequestParam final String searchTerm) {
    Mono<SearchResponse> fasMono = searchService.getSearchResults(searchTerm, "fh");
    Mono<SearchResponse> esMono = searchService.getSearchResults(searchTerm, "es");
    Mono<CombinedResults> combinedResults = 
        fasMono
          .flatMap(fh -> esMono.map(es -> new CombinedResults(fh, es)));
    return combinedResults;
}

这样，您就返回了一个Mono对象，其中包含您想要的内容作为响应。操作链fasmono.flatmap与esmono.map在两个Mono发出项时生成combinedresults。当尝试将两个单声道合并为一个时，这种组合是相当常见的。我认为您也可以使用zip操作符来加入单声道。所有这些都与WebClient无关。如果getSearchResults只执行异步非阻塞操作，那么所有操作都是异步非阻塞的。