Java 9: Reactive programming with Flow API

In a previous post about Reactive programming with Java 8, we looked into reactive programming support by Reactor. Java 9 introduced reactive programming in Java with the Flow API. In this post, we will look at how the various components in the Flow API work with a few examples.

Reactor: Reactive Programming Java 8

One of the more interesting features in the upcoming release of Java 9 is the support for Reactive Programming in Java. At a high-level Reactive programming deals with asynchronous data streams. Reactive streams provides a standard for asynchronous stream processing. Java 9 supports Reactive programming implementing the Reactive Streams specification through the Flow API. But before the release of Java 9, there are ways to implement Reactive programming in Java 8. Reactor and RxJava are a couple of APIs to implement Reactive streams in Java 8. Reactor is used internally by the Spring Framework to it's own Reactive support in version 5. In this post, we will look into Reactor library.