RxJava: upstream never completes when error is swallowed

Question

I\'m using RxJava to iterate over a list of files, making a network call to upload each file, then collect the files that were successfully uploaded in a list and persist th

Answer 1

Your problem is that Single can only result in two values, a successful result or a failure. Turning the failure in an 'ignored' state can be done by first converting it to a Maybe and then using essentially the same code to handle failure and success.

Maybe.onErrorResumeNext with a return value of Maybe.empty() would result in 0 or 1 results while Maybe.map only executes if it has a value, accurately handling the problem as you've described it.

Adapted code:

        .flatMapMaybe { file ->
            uploadFile(file).toMaybe()
                    .onErrorResumeNext { error: Throwable ->
                        log(error)
                        Maybe.empty()
                    }
                    .map { response ->
                        file.id = response.id
                        file
                    }
        }