reactor-core VS initializr

I was exploring reactive streams with project reactor and I encountered a use case where I needed to skip to the next event if an error occurred during the processing of the current event (e.g. deserialization issue).

Kotlin also has a construct for asynchronous collections/streams. Kotlin's version of AsyncSequence is called a Flow. Just as Swift's AsyncSequence builds upon prior experience with RxSwift and Combine, Kotlin's Flow APIs build upon earlier stream/collection APIs in the JVM ecosystem: Java's RxJava, Java8 Streams, Project Reactor, and Scala's Akka.

Java's projectreactor.io ? It is widely used in Java world, see Spring WebFlux.

I guess more a closer comparison would be with the Project Reactor https://projectreactor.io/ which is also a low level framework for data processing.

Spring Framework is one of the most popular choices for web applications. It comes with a great ecosystem, tooling, and support. Spring applications are mainly written in Java. While they can serve quite well in many different domains and use cases, they may not be a good fit for modern-day applications which require low-latency and high-throughput. This is where the reactive programming paradigm could help because the paradigm is designed to address these issues by its non-blocking nature. Spring already supports reactive programming via Project Reactor.

The reactive streams API provides the specification for non-blocking async streams processing with back pressure mechanism, and Project Reactor is an implementation written in java.

https://projectreactor.io/ https://docs.oracle.com/javase/8/docs/api/java/util/stream/Stream.html https://rxjs.dev/ https://developer.android.com/kotlin/coroutines https://developer.apple.com/documentation/combine

With respect to Loom, it could be much easier for synchronous and reactive code to interoperate using schedulers that take advantage of Loom. The impact of Loom on Project Reactor was discussed in #3084, you might find it interesting.

The best way, for generating a ready-to-run application in Java you can use the Spring Boot Initializr tool.

curl --location 'https://start.spring.io/starter.zip?type=maven-project&language=java&bootVersion=3.2.2&baseDir=ms-xcoffee&groupId=com.xcoffee&artifactId=ms-xcoffee&name=ms-xcoffee&description=Demo%20project%20for%20Spring%20Boot&packageName=com.xcoffee.ms-xcoffee&packaging=jar&javaVersion=21&dependencies=webflux%2Clombok%2Cvalidation' | tar -xzvf -

In this segment we will create a basic Spring boot app from Spring Initializer. Add the below dependencies:

Add the following MongoDB dependencies in your pom.xml or use spring initializer and select the Spring Data MongoDB dependency:

I created all of these applications using start.spring.io's REST API and HTTPie.

An easy way to create the skeleton project is to visit Spring Initializr, I set the Project to Gradle - Groovy, Language to Java, and add Spring Web dependency. Then it's just to generate the project and unpack it.

Create a new Spring Boot application using the Spring Initializr. You can use the web version or the curl command below. Use the default for most of the options. For the dependencies, select web, and okta. For the build tool, select Gradle.

I will start with a simple example of a cloud function, which is the same as a rest endpoint in the classical spring boot web application. You can create a project from your favorite IDE or from Spring Initliazr.