At the moment, technology plays a major role in the success of businesses and in reaching out to more users as early as possible. This demand will increase day by day. Along with the increase in the demand, the user expectations also have increased. Now, the users are demanding a quick, more responsive, and reliable response. Reactive programming is a programming model that helps in tackling the essential complexity that comes with writing such applications. We, as Java developers, are very much familiar with the imperative style of programming; however, now to tackle the essential complexity, reactive programming uses declarative and functional paradigms to build the programs. This book aims at making the paradigm shift easily by discussing the concepts about functional programming in depth.
This book begins with explaining what reactive programming and the Reactive Manifesto is, and about the Reactive Streams specification. It uses Java 9 to introduce the declarative and functional paradigm, which is very necessary to write programs in reactive style. It explains Java 9's Flow API, an adoption of the Reactive Streams specification. From this point on, it focuses on RxJava 2.0, covering topics like such as creating, transforming, filtering, combining, and testing Observables. It will then talk about how to use Java's popular framework, Spring, to build event-driven, reactive apps and its deployment on the server. By the end of the book, readers you will be fully equipped with the tools and techniques to implement robust event-driven reactive applications.