rxjava: Can I use retry() but with delay?

Question

I am using rxjava in my Android app to handle network requests asynchronously. Now I would like to retry a failed network request only after a certain time has passed.

Answer 1

For Kotlin & RxJava1 version

class RetryWithDelay(private val MAX_RETRIES: Int, private val DELAY_DURATION_IN_SECONDS: Long)
    : Function1<Observable<out Throwable>, Observable<*>> {

    private val START_RETRY: Int = 1

    override fun invoke(observable: Observable<out Throwable>): Observable<*> {
        return observable.delay(DELAY_DURATION_IN_SECONDS, TimeUnit.SECONDS)
            .zipWith(Observable.range(START_RETRY, MAX_RETRIES),
                object : Function2<Throwable, Int, Int> {
                    override fun invoke(throwable: Throwable, attempt: Int): Int {
                        return attempt
                    }
                })
    }
}

Answer 2

Simply do it like this:

                  Observable.just("")
                            .delay(2, TimeUnit.SECONDS) //delay
                            .flatMap(new Func1<String, Observable<File>>() {
                                @Override
                                public Observable<File> call(String s) {
                                    L.from(TAG).d("postAvatar=");

                                    File file = PhotoPickUtil.getTempFile();
                                    if (file.length() <= 0) {
                                        throw new NullPointerException();
                                    }
                                    return Observable.just(file);
                                }
                            })
                            .retry(6)
                            .subscribe(new Action1<File>() {
                                @Override
                                public void call(File file) {
                                    postAvatar(file);
                                }
                            }, new Action1<Throwable>() {
                                @Override
                                public void call(Throwable throwable) {

                                }
                            });