Convert Publisher to Maybe>

Question

I have the below method

public Maybe<HttpResponse<?>> post(Publisher<CompletedFileUpload> files) {
        MultipartBody.Builder requestBody = MultipartBody.builder();
        return Flowable.fromPublisher(files).flatMap(file -> {
            requestBody
                    .addPart("file", file.getFilename(), MediaType.TEXT_PLAIN_TYPE, file.getBytes())
                    .addPart("id", "asdasdsds");
            return this.iProductClient.post(requestBody.build());
        });
    }

The return type from this.iProductClient.post(requestBody.build()); is Maybe<HttpResponse<?>>

How can I convert the below code to return Maybe<HttpResponse<?>>, currently the below method has error

return Flowable.fromPublisher(files).flatMap(file -> {
            requestBody
                    .addPart("file", file.getFilename(), MediaType.TEXT_PLAIN_TYPE, file.getBytes())
                    .addPart("id", "asdasdsds");
            return this.iProductClient.post(requestBody.build());
        });

You have presumably multiple files and thus multiple `Maybe`s. How should they be turned into one `Maybe` from a logic stance? — akarnokd, Mar 08 '21 at 08:20
@akarnokd basically what I want is to loop all the files and add to the MultipartBody, and call this.iProductClient.post(requestBody.build()). However the return type of post method is Maybe>. Thus I need to return Maybe — San Jaisy, Mar 08 '21 at 08:26

score 1 · Accepted Answer · answered Mar 08 '21 at 09:12

1

You can use collect and then flatmap in the requrest sending:

return Flowable.fromPublisher(files)
    .collect(MultipartBody::builder, (requestBody, file) -> {
        requestBody
            .addPart("file", file.getFilename(), MediaType.TEXT_PLAIN_TYPE, file.getBytes())
            .addPart("id", "asdasdsds");
    })
    .flatMapMaybe(requestBody -> iProductClient.post(requestBody.build()))
    ;

answered Mar 08 '21 at 09:12

akarnokd

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Is there any way on flatMapMaybe(requestBody -> iProductClient.post(requestBody.build())) to check if addPart has been added or not to the requestBody ? – San Jaisy Mar 11 '21 at 08:53
What properties does `MultipartBody` have? – akarnokd Mar 11 '21 at 10:10
Didn't find such properties to check. It has build, addpart methods – San Jaisy Mar 11 '21 at 10:42
https://square.github.io/okhttp/4.x/okhttp/okhttp3/-multipart-body/size/ – akarnokd Mar 11 '21 at 11:06
well I tried flatMapMaybe(requestBody -> { if(requestBody.size)}), but size is not present – San Jaisy Mar 11 '21 at 13:43
In Java, it is a method: `size()`. – akarnokd Mar 11 '21 at 14:22

Convert Publisher to Maybe>

1 Answers1