What is Spring WebFlux and how is it different from Spring MVC?

Spring WebFlux is a reactive web framework introduced in Spring 5 that supports asynchronous and non-blocking programming. It is designed to handle a large number of concurrent requests efficiently by using reactive streams and Project Reactor.

Key Points: • Spring WebFlux follows a non-blocking and asynchronous programming model. • It uses Reactor types such as Mono and Flux to handle reactive data streams. • Spring MVC follows a synchronous and blocking request-processing model. • WebFlux can handle high concurrency with fewer threads and system resources. • Spring MVC is generally preferred for traditional CRUD applications, while WebFlux is suitable for real-time and highly scalable systems.

Example: Applications such as chat systems, live notifications, streaming services, and IoT platforms often benefit from WebFlux because they handle many concurrent connections efficiently.

Code Example:

@GetMapping("/user")
public Mono<String> getUser() {
    return Mono.just("Amol");
}

Interview Tip: A concise interview answer is:

"Spring WebFlux is a reactive, non-blocking web framework introduced in Spring 5. Unlike Spring MVC, which uses a synchronous and blocking model, WebFlux uses an asynchronous and non-blocking approach, making it more suitable for high-concurrency and event-driven applications."

Quick Comparison:

Spring MVC: • Synchronous and blocking • One thread per request • Suitable for traditional web applications

Spring WebFlux: • Asynchronous and non-blocking • Efficient thread utilization • Suitable for reactive and high-concurrency applications