Book Image

Learning RxJava

By : Thomas Nield
Book Image

Learning RxJava

By: Thomas Nield

Overview of this book

RxJava is a library for composing asynchronous and event-based programs using Observable sequences for the JVM, allowing developers to build robust applications in less time. Learning RxJava addresses all the fundamentals of reactive programming to help readers write reactive code, as well as teach them an effective approach to designing and implementing reactive libraries and applications. Starting with a brief introduction to reactive programming concepts, there is an overview of Observables and Observers, the core components of RxJava, and how to combine different streams of data and events together. You will also learn simpler ways to achieve concurrency and remain highly performant, with no need for synchronization. Later on, we will leverage backpressure and other strategies to cope with rapidly-producing sources to prevent bottlenecks in your application. After covering custom operators, testing, and debugging, the book dives into hands-on examples using RxJava on Android as well as Kotlin.
Table of Contents (21 chapters)
Title Page
About the Author
About the Reviewers
Customer Feedback

Using onBackpressureXXX() operators

If you are provided a Flowable that has no backpressure implementation (including ones derived from Observable), you can apply BackpressureStrategy using onBackpressureXXX() operators. These also provide a few additional configuration options. This can be helpful if, for example, you have a Flowable.interval() that emits faster than consumers can keep up. Flowable.interval() cannot be slowed down at the source because it is time-driven, but we can use an onBackpressureXXX() operator to proxy between it and the downstream. We will use Flowable.interval() for these examples, but this can apply to any Flowable that does not have backpressure implemented.


Sometimes, Flowable may simply be configured with BackpressureStrategy.MISSING so these onBackpressureXXX() operators can specify the strategy later.



The onBackPressureBuffer()will take an existing Flowable that is assumed to not have backpressure implemented and then essentially apply...