GraalVM Spring Native Image AOT

Kicking Spring Native's tires

I’ve been playing with GraalVM AOT compilation capability since I became aware of it. As a long-time Spring aficionado, I carefully monitored the efforts that the engineers at Tanzu have put into making Spring AOT-compatible. Recently, they announced the beta version of the integration. In this post, I want to check how easy it is to produce a (working!) Docker image from an existing Spring Boot application. Introduction GraalVM provides many different features. Among them, the componen

Reactive Rx Coroutines Backpressure

Backpressure in Reactive Systems

Mid-January, I held a talk at Kotlin.amsterdam based on my post Migrating from Imperative to Reactive (a Spring Boot application). Because it was a Kotlin meetup, I demoed Kotlin code, and I added a step by migrating the codebase to coroutines. During Q&A, somebody asked whether coroutines implemented backpressure. I admit I was not sure of the answer, so I did a bit of research. This post provides information on backpressure in general and how RxJava (v3), Project Reactor and Kotlin’

Kubernetes minikube kind

Goodbye minikube

I’ve been using minikube as my local cluster since I started to learn Kubernetes. But I’ve decided to let it go in favor of kind. Here’s the story. A couple of weeks ago, I gave my talk on Zero Downtime on Kubernetes. A demo is included in the talk, as with most of my presentations. While rehearsing in the morning, the demo worked, albeit slowly. Two days before that, I had another demo that also uses Kubernetes and it was already slow. But I didn’t take the hint. Duri

monitoring DevOps Spring Boot Quarkus Micronaut MicroProfile

Monitoring across frameworks

Gone are the times when developers' jobs ended with the release of the application. Nowadays, developers care more and more about the operational side of IT: perhaps they operate applications themselves, but more probably, their organization fosters increased collaboration between Dev and Ops. I started to become interested in the Ops side of software when I was still a consultant. When Spring Boot released the Actuator, I became excited. Via its convention-other-configuration nature, it was po

Functional Programming API Optional Stream

Optional.stream()

This week, I learned about a nifty 'new' feature of Optional that I want to share in this post. It’s available since Java 9, so its novelty is relative. Let’s start with the following sequence to compute the total price of an order: public BigDecimal getOrderPrice(Long orderId) { List<OrderLine> lines = orderRepository.findByOrderId(orderId); BigDecimal price = BigDecimal.ZERO; (1) for (OrderLine line : lines) { price = price.add(line.getPrice());

GUI SWT Kotlin

The state of JVM desktop frameworks: SWT

This is the 3rd post in the The state of JVM desktop frameworks focus series. This series is dedicated to the state of JVM desktop frameworks. After having had a look at Swing the previous week, this post focuses on the Standard Widget Toolkit. SWT originates from the Eclipse project, an IDE. For Eclipse, the developers built a dedicated framework to build their graphic components upon. Swing implements the drawing of widgets in Java from scratch. On the opposite, SWT is a thin wrapper API that r