Introduction to Reactive Programming in Java with Project Reactor we will go through below: 1. Introduction to Reactive Programming What is reactive programming? Key principles of reactive systems: Responsive : Systems should respond in a timely manner. Resilient : Systems should be fault-tolerant. Elastic : Systems should scale as needed. Message-driven : Systems should use asynchronous messaging. Comparison between imperative programming and reactive programming. 2. Understanding Reactive Streams Publisher , Subscriber , Subscription , and Processor interfaces. The four key signals: onNext() , onComplete() , onError() , and onSubscribe() . Backpressure handling in reactive systems. 3. Introduction to Project Reactor What is Project Reactor? Key classes: Mono and Flux . Mono : Represents 0 or 1 item. Flux : Represents 0 to N items. Non-blocking nature and how it helps in building scalable systems. 4. Building a Reactive Application with Project Reactor Demonstrating how to use Mono
Stream flatMap() in Java with examples Stream flatMap(Function mapper) returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Stream flatMap(Function mapper) is an intermediate operation . These operations are always lazy. Intermediate operations are invoked on a Stream instance and after they finish their processing, they give a Stream instance as output. Note : Each mapped stream is closed after its contents have been placed into this stream. If a mapped stream is null, an empty stream is used, instead. flatMap() V/s map() : 1) map() takes a Stream and transform it to another Stream. It applies a function on each element of Stream and store return value into new Stream. It does not flatten the stream. But flatMap() is the combination of a map and a flat operation i.e, it applies a function to elements as well as flatten them. 2) map() is used for