In today’s app-driven era, when programs are asynchronous and responsiveness is so vital, reactive programming can help you write code that’s more reliable, easier to scale, and better-performing. With this practical book, Java developers will first learn how to view problems in the reactive way, and then build programs that leverage the best features of this exciting new programming paradigm.Authors Tomasz Nurkiewicz and Ben Christensen include concrete examples that use the RxJava library to solve real-world performance issues on Android devices as well as the server. You’ll learn how RxJava leverages parallelism and concurrency to help you solve today’s problems. This book also provides a preview of the upcoming 2.0 release.Write programs that react to multiple asynchronous sources of input without descending into "callback hell"Get to that aha! moment when you understand how to solve problems in the reactive wayCope with Observables that produce data too quickly to be consumedExplore strategies to debug and to test programs written in the reactive styleEfficiently exploit parallelism and concurrency in your programsLearn about the transition to RxJava version 2