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)

The Publisher and Subscriber APIs in a Reactor

The previous chapter provided you with a brief introduction to the evolution of the reactive paradigm. In that chapter, we discussed how Reactive Streams enable us to perform reactive modeling in imperative languages, such as Java. We also discussed the key components in reactive—the publisher and subscriber. In this chapter, we will cover these two components in detail. Since Reactive Streams is a specification, it does not provide any implementations of the two components. It only lists the responsibilities of the individual components. It is left to implementation libraries, such as Reactor, to provide concrete implementations for the interfaces. Reactor also provides different methods for instantiating publisher and subscriber objects.

We will cover the following topics in this chapter:

  • Comparing streams to existing Java...