Spring Boot Spring Boot WebFlux and Reactive Programming

Question 1

Which Spring Boot starter is required to use Spring WebFlux?

Accepted Answer

spring-boot-starter-webflux

Answer

The `spring-boot-starter-webflux` dependency pulls in Project Reactor and Netty to enable reactive web support in Spring Boot.

Question 2

What is the reactive equivalent of Spring MVC's RestTemplate in Spring WebFlux?

Accepted Answer

WebClient

Answer

WebClient is the non-blocking, reactive HTTP client introduced in Spring 5 that replaces the deprecated RestTemplate for reactive applications.

Question 3

Which two types does Project Reactor provide for reactive streams in Spring WebFlux?

Accepted Answer

Flux and Mono

Answer

Project Reactor provides `Mono` (0 or 1 element) and `Flux` (0 to N elements) as the core reactive types used in Spring WebFlux.

Question 4

What default embedded server does Spring WebFlux use instead of Tomcat?

Accepted Answer

Netty

Answer

Spring WebFlux defaults to Netty as the embedded server because it is event-loop-based and designed for non-blocking I/O.

Question 5

Which annotation is used to define a functional-style route handler bean in Spring WebFlux?

Accepted Answer

@RouterFunction

Answer

`RouterFunction` is the functional interface used with `RouterFunctions.route()` to declare routes without annotation-based controllers in WebFlux.

Spring Boot Practice Test