Java Spring WebFlux Vs RxJava

Both Spring WebFlux and RxJava are libraries that provide responsive design in Java applications, but they have different purposes and use cases. In this article, we will learn what is Spring WebFlux and RxJava with proper examples. But RxJava is general purpose and can be used in a variety of contexts, while Spring WebFlux is specifically designed to build responsive web applications within the Spring ecosystem.

Java Spring WebFlux

Spring WebFlux is a part of the Spring framework that provides responsive scheduling support for building asynchronous blocking event-driven applications. Mostly this Spring WebFlux is used to develop Web Applications that require high concurrency and scalability. and built on top of the WebFlux Project Reactor. This can provide responsive policy support.

Example:

Here, we have created one API endpoint by using @GetMapping that is testing. After running this program open the browser then open this URL through that browser. First, we print the Mono.just method statement then mapped with s lambda expression.

Java

import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import reactor.core.publisher.Mono;

@RestController
public class ExampleController {
    
    // Endpoint for testing
    @GetMapping(value = "/testing", produces = MediaType.TEXT_PLAIN_VALUE)
    public Mono<String> hello() {
        return Mono.just("Welcome To GeeksForGeeks")
                   .map(s -> s + " - processed");
    }
}

Output:

RxJava

RxJava is one of the libraries for composing asynchronous and event-based programs using observable sequence. And It provides APIs for working with reactive streams of data. RxJava is widely used in Android development and general Java applications for handling asynchronous operations like network requests, database operations and UI events.

Example:

In this example, we called Observable.just() method. In this method, we passed one String message, then we have called subscription method for returning the publisher. Then mapped with one lambda expression that is s. Finally, it prints the result by using subscribe() method.

Java

import io.reactivex.Observable;
import io.reactivex.schedulers.Schedulers;

public class RxJavaExample {
    public static void main(String[] args) {
        // Create an observable emitting a single item
        Observable.just("Hello, world!")
                // Subscribe on IO scheduler for the source emission
                .subscribeOn(Schedulers.io())
                // Observe on a single-threaded scheduler for downstream processing
                .observeOn(Schedulers.single())
                // Transform the emitted item
                .map(s -> s + " - processed")
                // Subscribe and print the result
                .subscribe(System.out::println);
    }
}

Output:

Hello, world! - processed

Difference between Java Spring WebFlux and RxJava

Below we provide differences between Spring WebFlux and RxJava in the form of table. Here we can get a clarity on Java Spring WebFlux and RxJava.

Feature	Java Spring WebFlux	RxJava
Purpose	Reactive Web framework used for building non-blocking applications.	It has General purpose library for composing synchronous programs.
Concurrency Model	It is built on Project Reactor and Integrates with Spring.	It uses Its own concurrency model and schedulers.
Integration	Seamless integration with other Spring Components.	It can be integrated with various libraries and frameworks.
Backpressure Support	Built in support for Backpressure.	Backpressure support via specific operators.
Use Cases	It is Specifically designed for building reactive web applications.	It is widely used in Android development and general java applications.
Error Handling	It provides mechanisms for handling errors in reactive flows.	It offers operators for handling errors and exceptions.
Community Support	It has Strong community support within the Spring ecosystem.	It has well established community particularly in android development.
Deployment	Mostly used in Spring Boot Applications.	Mostly used in various java applications and Android Applications.