Webflux 错误 - 不存在类型变量 R 的实例，因此 Flux<UUID> 符合 Mono<>

Question

我使用 Spring Boot 和 Webflux。

在我的代码中，我尝试返回 Flux，但我从 intellij 收到以下错误并且代码标记为红色：

no instance(s) of type variable(s) R exists so that Flux<UUID> conforms to Mono<>

我的代码：

public Flux<UUID> deleteCCProtections(Mono<ProtectionSetRequest> protectionSetRequest) {
        return protectionSetRequest.flatMap(
            request ->
                protectionSetRepository
                    .findByProtectionSetIdIn(request.getProtectionSetIds())
                    .collectList()
                    .flatMap(
                        protectionSet ->  //this line is marked red in Intellij
                            deleteCCProtectionset(protectionSet, request.getDeleteBackups()))); //this line is marked red in Intellij
    }
    
    private Flux<UUID> deleteCCProtectionset(
        List<ProtectionSet> protectionSets, boolean deleteRecoveryPoints) {
        return Flux.fromIterable(protectionSets)
            .flatMap(
                protectionSet ->
                    protectorRepository
                        .findByProtectionId(protectionSet.getProtectionId())
                        .flatMap(
                            protector ->
                                Mono.zip(
                                    protectBatchService.delete(protector),
                                    protectionSetRepository.delete(protectionSet))
                                    .flatMap(
                                        tuple ->
                                            protectionService.sendUnprotectCommand(
                                                tuple.getT1()))
                                    .doOnNext(subscriptionResourceService::cancelSubscriptionResources)
                                    //
                                    // .doOnNext(agentDataServiceApi::setProtectedResources) //void
                                    .doOnNext(schedulerService::deleteProtection))); //void
    }

我做错了什么？

更新

当我从参数 deleteCCProtections(Mono protectionSetRequest 中删除 Mono 时，我的代码会编译 - 为什么？？？我将 Mono 从控制器获取到服务...

工作代码但没有 Mono

public Flux<UUID> deleteCCProtections(ProtectionSetRequest protectionSetRequest) {
        return protectionSetRepository
                 .findByProtectionSetIdIn(protectionSetRequest.getProtectionSetIds())
                    .collectList()
                    .flatMapMany(
                        protectionSet ->  //this line is marked red in Intellij
                            deleteCCProtectionset(protectionSet, request.getDeleteBackups()))); //this line is marked red in Intellij
    }
    
    private Flux<UUID> deleteCCProtectionset(
        List<ProtectionSet> protectionSets, boolean deleteRecoveryPoints) {
        return Flux.fromIterable(protectionSets)
            .flatMap(
                protectionSet ->
                    protectorRepository
                        .findByProtectionId(protectionSet.getProtectionId())
                        .flatMap(
                            protector ->
                                Mono.zip(
                                    protectBatchService.delete(protector),
                                    protectionSetRepository.delete(protectionSet))
                                    .flatMap(
                                        tuple ->
                                            protectionService.sendUnprotectCommand(
                                                tuple.getT1()))
                                    .doOnNext(subscriptionResourceService::cancelSubscriptionResources)
                                    //
                                    // .doOnNext(agentDataServiceApi::setProtectedResources) //void
                                    .doOnNext(schedulerService::deleteProtection))); //void
    }

Answer 1

由于deleteCCProtectionset 返回Flux<UUID>，您应该在deleteCCProtections 方法中使用flatMapMany 而不是flatMap。

public Flux<UUID> deleteCCProtections(Mono<ProtectionSetRequest> protectionSetRequest) {
    return protectionSetRequest.flatMapMany(request -> protectionSetRepository
            .findByProtectionSetIdIn(request.getProtectionSetIds())
            .collectList()
            .flatMapMany(protectionSet -> deleteCCProtectionset(protectionSet, request.getDeleteBackups())));
}