Book Image

Hands-On Reactive Programming with Reactor

By : Rahul Sharma
Book Image

Hands-On Reactive Programming with Reactor

By: Rahul Sharma

Overview of this book

Reactor is an implementation of the Java 9 Reactive Streams specification, an API for asynchronous data processing. This specification is based on a reactive programming paradigm, enabling developers to build enterprise-grade, robust applications with reduced complexity and in less time. Hands-On Reactive Programming with Reactor shows you how Reactor works, as well as how to use it to develop reactive applications in Java. The book begins with the fundamentals of Reactor and the role it plays in building effective applications. You will learn how to build fully non-blocking applications and will later be guided by the Publisher and Subscriber APIs. You will gain an understanding how to use two reactive composable APIs, Flux and Mono, which are used extensively to implement Reactive Extensions. All of these components are combined using various operations to build a complete solution. In addition to this, you will get to grips with the Flow API and understand backpressure in order to control overruns. You will also study the use of Spring WebFlux, an extension of the Reactor framework for building microservices. By the end of the book, you will have gained enough confidence to build reactive and scalable microservices.
Table of Contents (13 chapters)

Broadcasting

In networking, broadcasting is defined as simultaneous event publishing to multiple receivers. In terms of Reactive Streams, this means simultaneous event publishing to multiple subscribers. Until now, we have subscribed to cold publishers, where each subscription generates a new series of events. We have even subscribed to hot publishers, where the publisher keeps pushing events without waiting for a subscriber. Each subscriber gets the same event as soon as it is generated. A hot publisher may look like a broadcasting event, but there is a key difference with regard to the start of the event generation stream. Reactor allows us to create a ConnecatableFlux, capable of waiting for n subscribers before starting event generation. It then keeps publishing each event to all of its subscribers.

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