The document discusses reactive programming, an asynchronous programming paradigm focused on data streams and change propagation. It introduces reactive streams as a standard for asynchronous stream processing with non-blocking back pressure and outlines various programming interfaces such as subscription, processor, subscriber, and publisher. Additionally, it mentions the use of Project Reactor for building reactive systems and encourages feedback on the presentation.

1. https://github.com/orlandovald/reactive-tweets
Reactive Tweets
Orlando Valdez / @orlandovald_
Charlotte JUG / @cltjug / cltjug.org

2. Reactive programming is an asynchronous programming
paradigm concerned with data streams and the
propagation of change.
https://en.wikipedia.org/wiki/Reactive_programming
Reactive Programming

3. https://www.reactive-streams.org/
Reactive Streams
Reactive Streams is an initiative to provide a
standard for asynchronous stream processing
with non-blocking back pressure

4. What is it trying to solve?
Application
GET /api/tweets
ServletContainer
BlockingI/O
GET /api/tweets
GET /api/tweets

5. Non-blocking event loop
GET /api/tweets
Response

6. https://github.com/reactive-streams/reactive-streams-jvm/blob/v1.0.3/README.md#specification
Reactive Streams - Spec
public interface Subscription {
public void request(long n);
public void cancel();
}
public interface Processor<T, R> extends
Subscriber<T>, Publisher<R> { }
public interface Subscriber<T> {
public void onSubscribe(Subscription s);
public void onNext(T t);
public void onError(Throwable t);
public void onComplete();
}
public interface Publisher<T> {
public void subscribe(Subscriber<? super T> s);
}

7. Reactive Streams - Implementations

8. https://projectreactor.io/
Project Reactor
• Reactor is a fully non-blocking foundation with
efficient demand management
• Spring 5 dependency
• 2 Reactive Composable types
‣ Mono<T> for 0..1 elements
‣ Flux<T> for 0..N elements

9. Let’s build a reactive system
stream.twitter.com
Server Sent
Events (SSE)
Spring WebfluxSpring Data

10. Orlando Valdez / @orlandovald_
https://github.com/orlandovald/reactive-tweets
Reactive Tweets
Charlotte JUG / @cltjug / cltjug.org
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