Build Reactive REST APIs with Spring WebFlux and Spring Boot

Explore event driven streams in reactive programming, where publishers emit on_next events to subscribers, with asynchronous, non blocking data flow and on_complete and on_error signals.

Explore the reactive streams specification and its four interfaces—publisher, subscriber, subscription, and processor—and understand data flow, backpressure, and signals like on_next, on_complete, and on_error.

Learn how to enable logs for a Flux publisher using the meter log, observe on next, on complete, and on subscribe events, and verify data flow in the reactive streams.

Convert an Optional to a Mono in a reactive Spring WebFlux context, showing value emission from non-empty optionals and completion for empty or null ones. Subscribe and log to verify.

Convert a stream into a flux, then subscribe to the flux and print each value, observing on next and on complete events for a list of strings.

Convert arrays and lists into Flux using Flux.fromIterable, subscribe to observe onNext and onComplete events, and explore empty and null cases with sample values like John, Raj, and Peter.

Apply a filter on flux using predicates to select names with more than three characters, demonstrating on next and on complete events.

Explore mapping data in a flux with the map operation, transforming orders to IDs, and filtering by amount to produce long values.

Learn how flatMap on Flux enables one-to-many data transformation, converting a single input (order) into multiple items, with practical examples of retrieving and printing items per order.

Explore the request() method to control backpressure on a flux of integers, pulling five or two items at a time and handling on next, on complete, and on error.

Explore using a parallel scheduler to move downstream operations to new threads, revealing the main thread versus parallel threads and when to apply parallel scheduling in reactive streams.

Explore delaying the publication of flux elements using delay elements and duration, setting a one-second interval between values, and observing how parallel cellular threads handle each item.

Explore building a reactive get api with flux in Spring WebFlux, returning a flux of orders and streaming data in an event stream, with a delay illustrating streaming.

Create the first handler in a reactive spring boot app by defining an order handler component that returns a flux of orders and notes router setup for next.

Extend the router and handler to add multiple routes in a reactive rest api, using a functional style with get, post, and delete mappings returning order objects via mono.