Flowable 执行任务并返回 String Rx Java ReactiveX 列表

问题描述

执行任务并最终使用 Flowable rxjva3 返回值。我有以下代码

public Maybe<List<String>> uploadobject(Publisher<CompletedFileUpload> images) {
        Storage storage = StorageOptions.getDefaultInstance().getService();
        var returnValue = Flowable.frompublisher(images)
                .collect((List<String> returnImages,CompletedFileUpload image) -> {
                    BlobId blobId = BlobId.of(googleUploadobjectConfiguration.bucketName(),image.getName());
                    BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();
                    Blob updatedImage = storage.create(blobInfo,image.getBytes());
                    returnImages.add(updatedImage.getName());
                })
                .flatMapMaybe(returnImages -> Maybe.just(returnImages));
    }

基本上，它会迭代并将图像上传到谷歌存储。那么返回的媒体 URL 应该返回到 String 的列表中。然而，尝试了下面的代码，返回类型是 Maybe<U>。执行此操作的正确方法是什么？

更新 1

Flowable.frompublisher(images).collect(ArrayList::new,(returnImages,image) -> {
            BlobId blobId = BlobId.of(googleUploadobjectConfiguration.bucketName(),image.getName());
            BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();
            Blob updatedImage = storage.create(blobInfo,image.getBytes());
            returnImages.add(updatedImage.getName());
            LOG.info(
                    String.format("File %s uploaded to bucket %s as %s",image.getName(),googleUploadobjectConfiguration.bucketName(),image.getName())
            );
        }).flatMapMaybe((returnImages)-> List.of(returnImages));

这也不对，返回类型应该是Maybe<List<String>>

解决方法

从注释中，使用两个参数 collect，然后使用 toMaybe。您可能需要加强集合类型，如下所示：

Flowable.fromPublisher(images)
.<List<String>>collect(ArrayList::new,(returnImages,image) -> {
    BlobId blobId = BlobId.of(googleUploadObjectConfiguration.bucketName(),image.getName());
    BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();
    Blob updatedImage = storage.create(blobInfo,image.getBytes());
    returnImages.add(updatedImage.getName());
    LOG.info(
        String.format("File %s uploaded to bucket %s as %s",image.getName(),googleUploadObjectConfiguration.bucketName(),image.getName())
            );
}).toMaybe();