Overview of the Java Reactive Streams API

This video provides an overview of Java reactive streams, focusing on the key abstractions essential for understanding reactive streams, namely publishers, subscribers, and subscriptions, and explaining their roles and interactions. I also introduce the Java Flow API, available since Java 9, which supports stream-oriented publisher-subscriber patterns and flow control. Key design patterns, such as the Iterator and Observer patterns from the Gang of Four book, are discussed to show how they are applied to implement reactive streams. I also emphasize the subscriber-driven nature of data flow in reactive streams, where data transmission is lazy and initiated by the subscriber's demand, highlighting the importance of the onSubscribe(), onNext(), onComplete(), and onError() methods in managing this flow.