Controllers are the integration point between Model and Resources in an AI. They act like the glue that binds together everything while taking care of business logic execution and response. The following Maven starter dependency needs to be added to enable Spring WebFlux:

<dependencies>
   ...
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-webflux</artifactId>
   </dependency>
</dependencies>

The preceding dependency will import Reactive Stream, Spring, and Netty dependencies to enable successful writing of Reactive-based web applications using Spring.