NetworkBoundResource 未按预期工作

Question

我有一些有线问题。当我第一次订阅时，它会进行网络调用，并将数据保存到数据库中，但永远不会执行，并且没有引发任何错误。loadFromDb()

为什么会发生这种情况？

    Flowable<Resource<List<List<DataSource>>>> getBoundResource(List<String> parentId) {

    return new RxNetworkBoundResource<List<List<DataSource>>,

            ContainerResponse>() {

        @Override

        void saveCallResult(@NonNull List<ContainerResponse> data) {

            for (ContainerResponse item : data) {

                // Saves data to database

                List<DataSource> items = item.items;

                containerDao.insert(items);

            }

        }

        @Override

        protected Flowable<List<List<DataSource>>> loadFromDb() {

            return Flowable.just(parentId).flatMapIterable(d -> d)

                    .flatMap(s -> containerDao.loadContainerByParentIdRx(s))

                    .distinct()

                    .doOnNext(data -> {

                        // I am able to get data here

                    })

                    .toList() // I'm not able to get data after toList()

                    .toFlowable()

                    .doOnNext(data -> {

                        // Nothing here

                    });

        }

Answer 1

请注意，仅在其上游完成后才会发出。医生.toList()此处的问题很可能是由于此代码返回了 未完成的 ：FlowablecontainerDao.loadContainerByParentIdRx(s)如果这永远不会完成，那么结果也不会完成，也不会发出任何东西。FlowableflatMaptoList()如果只查找数据库一次，则一个选项是将返回类型更改为 或 。例如，如果切换到 ，则可以执行以下操作：SingleMaybeMaybe&nbsp; &nbsp; @Override&nbsp; &nbsp; protected Flowable<List<List<DataSource>>> loadFromDb() {&nbsp; &nbsp; &nbsp; &nbsp; return Flowable.just(parentId).flatMapIterable(d -> d)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .flatMapMaybe(s -> containerDao.loadContainerByParentIdRx(s))&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .distinct()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .doOnNext(data -> {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // I am able to get data here&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; })&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .toList() // You should now get this as well.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .toFlowable()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .doOnNext(data -> {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Nothing here&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; });&nbsp; &nbsp; }