Introduction to the Reactive Backend

Reactive web server

In this chapter, you’ll learn how to develop the reactive web server. We’ll use Spring WebFlux, available since Spring 5 and included from the Spring Boot 2.3 version. We’ll connect to a Mongo database using its reactive driver with Spring Data, also via Spring Boot.

Two approaches

We’ll include two different web approaches within the same backend application:

1. A reactive style, using WebFlux and a MongoDB ReactiveCrudRepository.
2. The classical Spring Web MVC stack, using a blocking REST controller and a blocking MongoDB query.