Question 1

How to convert a List to a Flowable in RxJava?

Accepted Answer

Use Flowable.fromIterable(yourList) to create a stream from any Iterable. For arrays, use Flowable.fromArray(). This allows you to apply operators like map or filter directly to the collection elements in a reactive way.

Question 2

What's the difference between Observable and Flowable?

Accepted Answer

Observable is for unbounded streams without backpressure, ideal for UI events or short sequences. Flowable supports backpressure via the Reactive Streams spec, making it better for high-volume data like network responses where flow control is needed to prevent overload.

Question 3

RxJava vs Project Reactor: which should I use?

Accepted Answer

RxJava is a mature, standalone library with cross-language consistency via ReactiveX, great for general JVM projects. Project Reactor is often preferred in Spring Boot ecosystems due to tight integration, but both offer similar reactive capabilities—choice depends on framework alignment and team preference.

Question 4

How to handle errors in RxJava streams effectively?

Accepted Answer

Use operators like onErrorReturn to provide default values, onErrorResumeNext to switch to a fallback stream, or doOnError for side-effects. Place these strategically in the chain to ensure errors are caught and managed without breaking the entire pipeline.

Question 5

Best practices for testing RxJava code?

Accepted Answer

Leverage TestScheduler for time-based operations and TestSubscriber to assert emissions and completions. RxJava provides testing utilities in the io.reactivex package to mock streams and verify behavior without relying on real concurrency, simplifying unit tests.

Question 6

Can RxJava be used with Android without issues?

Accepted Answer

Yes, but compatibility depends on your Android API level and desugaring capabilities, as noted in the README. Use RxAndroid for main thread scheduling, and ensure you're on a supported RxJava version (4.x has better modern Java support but may require careful configuration).

Question 7

How to implement retry logic with exponential backoff?

Accepted Answer

Combine the retryWhen operator with a function that uses interval or timer to delay resubscriptions. For example, use Flowable.interval to increase delays between retries, ensuring failed streams are retried with growing pauses to handle transient errors gracefully.

GitHub Issues

What is GitHub Issues?

Overview

Use Cases

Best For

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions