A Java geek

Java Stream’s Collectors methods fit most use-cases. They allow returning either a Collection or a scalar. For the former, you use one of the toXXX() method, for the latter, one of the reducing() one. Let’s imagine an e-commerce platform that implements a shopping cart. The cart is modeled as the following: This diagram might translate into the following (abridged) code: Product.

This week’s post is pretty short. I’ve already written about overengineering, but this adds a personal touch. I had to rewrite my Jet Train demo to use another data provider, switching from a Swiss one to a Bay Area one. One of the main components of the demo is a streaming pipeline. The pipeline: Reads data from a web endpointTransforms data through several stepsWrites the final data into an in-memory data grid Most of the transform steps in #2 enrich the data.

Kotlin offers many exciting features. In general, developers tend to cite null safety as their favorite. For me, it’s function extensions. But delegation comes a close second. The delegation pattern The delegation pattern is described in the GoF book: Delegation is a way to make composition as powerful for reuse as inheritance [Lie86, JZ91]. In delegation, two objects are involved in handling a request: a receiving object delegates operations to its delegate.

Frameworks promise to speed up one’s development pace provided one follows the mainstream path. The path may be more or less narrow. I’m a big fan of the Spring ecosystem because its design is extensible and customizable at different abstraction levels: thus, the path is as large as you need it to be. Functional Programming is becoming more and more popular. Spring provides a couple of DSLs for the Kotlin language.

A couple of years ago, I attended a talk of my former colleague (but still friend) Volker Simonis. It gave me the idea to dig a bit into the subject of how to secure the JVM. From the material, I created a series of blog posts as well as a talk. From that point on, I submitted the talk at meetups and conferences, where it was well-received. Because I like to explore different areas, I stopped to submit other proposals. Still, the talk is in my portfolio, and it was requested again in 2021.

Posts that have been written about Hibernate’s LazyInitializationException could probably fill whole books. Yet, I believe each of them focuses on a particular aspect of it: some on a specific solution, some on how to solve it with Spring Boot, etc. I’d like this post to be the definitive guide on the subject, even though I’m pretty sure it won’t. At least, I’ll be able to point others to it.