What we will learn in this book?

 As stated earlier, RxJava is the ReactiveX port for Java. In this book, we will focus primarily on RxJava 2.0, but I will call out significant differences in RxJava 1.0. We will place priority on learning to think reactively and leverage the practical features of RxJava. Starting with a high-level understanding, we will gradually move deeper into how RxJava works. Along the way, we will learn about reactive patterns and tricks to solve common problems programmers encounter.
 
 In Chapter 2, The Observable and Subscribers, Chapter 3, Basic Operators, and Chapter 4, Combining Observables, we will cover core Rx concepts with Observable, Observer, and Operator. These are the three core entities that make up RxJava applications. You will start writing reactive programs immediately and have a solid knowledge foundation to build on for the rest of the book.
 
Chapter 5, Multicasting, Replaying, and Caching, and Chapter 6, Concurrency and Parallelization, will explore more of the nuances of RxJava and how to effectively leverage concurrency.

In Chapter 7, Switching, Throttling, Windowing, and Buffering and Chapter 8, Flowables and Backpressure, we will learn about the different ways to cope with reactive streams that produce data/events faster than they can be consumed.

Finally, Chapter 9, Transformers and Custom Operators, Chapter 10, Testing and Debugging, Chapter 11, RxJava on Android, and Chapter 12, Using RxJava with Kotlin New, will touch on several miscellaneous (but essential) topics including custom operators as well as how to use RxJava with testing frameworks, Android, and the Kotlin language.