Updated with the latest Maven coordinates, Java programming features, and API changes, this book is your guide to solving problems in writing asynchronous and event-based programs Key Features Explore a variety of tools and techniques used to solve problems in implementing concurrency and parallelization Learn about core operators in RxJava that enable you to express your code logic productively Apply RxJava with Kotlin to create responsive Android apps with better user experience Book Description RxJava is not just a popular library for building asynchronous and event-based applications; it also enables you to create a cleaner and more readable code base. In this book, you'll cover the core fundamentals of reactive programming and learn how to design and implement reactive libraries and applications. Learning RxJava will help you understand how reactive programming works and guide you in writing your first example in reactive code. You'll get to grips with the workings of Observable and Subscriber, and see how they are used in different contexts using real-world use cases. The book will also take you through multicasting and caching to help prevent redundant work with multiple Observers. You'll then learn how to create your own RxJava operators by reusing reactive logic. As you advance, you'll explore effective tools and libraries to test and debug RxJava code. Finally, you'll delve into RxAndroid extensions and use Kotlin features to streamline your Android apps. By the end of this book, you'll become proficient in writing reactive code in Java and Kotlin to build concurrent applications, including Android applications. What you will learn Discover different ways to create Observables, Observers, and Subscribers Multicast in order to push data to multiple destinations and cache and replay them Express RxJava idiomatically with the help of Kotlin features such as extension functions and data classes Become familiar with various operators available in RxJava to perform common transformations and tasks Explore RxJava's reactive types, including Flowable, Single, Maybe, and Completable Demystify Observables and how they express data and events as sequences Who this book is for This book is for Java developers who want to leverage reactive programming to develop more resilient and concurrent applications. If you're an RxJava user looking to get to grips with the latest features and updates in RxJava 3, this book is for you. Fundamental knowledge of core Java features and object-oriented programming will assist you in understanding the key concepts covered in this book.