Upgrading from JavaEE to JakartaEE using OpenRewrite

Posted by Joep Weijers on April 26, 2023

In our software, we have transitive dependencies on code from Java’s Enterprise Edition (JavaEE). The code is typically in javax.* packages. The owner of Java, Oracle, opensourced the JavaEE specification and has donated it to the Eclipse foundation. This however came with one very impacting condition: that the trademarked Java name is no longer used in the specifications. The specification rename to JakartaEE was pretty easy. Renaming all the packages to jakarta.* was not. This means that all code depending on JakartaEE has to be updated to use the new packages. Although some libraries manage to handle both javax.* and jakarta.* packages at the same time, you really only want to have only one of them. That also means that all libraries that you use have to be updated to use jakarta.* packages before you can successfully update your own code. Here is how we did it:

Solving the “artifact has been relocated” warnings in Maven 3.8.3

Posted by Joep Weijers on January 21, 2022

After updating to Maven 3.8.3, we have several warnings regarding the relocation of artifacts in our Maven builds. See for example the output of using Maven’s dependency plugin to analyze the dependency usage of an empty Maven project:

$ mvn dependency:analyze
[INFO] --- maven-dependency-plugin:2.8:analyze (default-cli) @ relocation-messages ---
[WARNING] The artifact xml-apis:xml-apis:jar:2.0.2 has been relocated to xml-apis:xml-apis:jar:1.0.b2
[INFO] No dependency problems found

End-of-life, the most important lifecycle of software

Posted by Joep Weijers on March 5, 2021

The most important phase in the lifecycle of software, is the final one: the end-of-life. My apekooi project the Online Watercoolerchat will reach end-of-life on the 16th of March 2021. Read on about the project and why you want to eventually get rid of your code.

Extracting a Heap Dump from a running OpenJ9 Java process in Kubernetes

Posted by Joep Weijers on November 26, 2020

At TOPdesk we run many Java services in our Service Architecture. We use the AdoptopenJDK OpenJ9 JRE as base image for our services running in Kubernetes. In this post we will find out how to get a Java Heap Dump from a Java application running on OpenJ9 JRE.

A Java Heap Dump is a snapshot of all the objects that are in memory in the JVM at a certain moment. Typically, a heap dump is created at the moment a Java application crashes because it runs out of memory. The heap dump can then show you what the application was doing in its dying moments, providing insight into potential memory leaks.

The technical aspect of public speaking: microphones

Posted by Joep Weijers on February 14, 2020

You may have a loud voice, but if you are addressing a group with more than twenty people, you will want some form of amplification. In this third and final installment of the technical aspects of public speaking, we will discuss how your audience can hear you properly using microphones.

The technical aspect of public speaking: coming on stage

Posted by Joep Weijers on February 7, 2020

Your presentation starts in a few minutes. It is your time to shine. You plug in your laptop and nothing happens. No slides on the big screen behind you. An already stressful moment becomes even more stressed. You’re starting to lose your audience.

Nobody wants to be in this situation. Here are some tips to make getting on stage a smooth process, even if unexpected events occur.

The technical aspect of public speaking: preparing slides

Posted by Joep Weijers on January 29, 2020

Public speaking can be pretty stressful. All eyes will be on you and the last thing you wish to happen is a problem with your slides or microphone. A flawless presentation requires proper preparation. We have gathered some best practices, drawn from practical experience, to help you prepare your presentation. With these tips and tricks you will confidently walk on-stage, knowing that slides and sound will not hamper your presentation.

Preparing (and cheating on) an ignite talk

Posted by Joep Weijers on February 5, 2019

In an ignite talk, a speaker has 20 slides to present a topic to you. The slides automatically advance every 15 seconds, so they have exactly 5 minutes to get their point across. Topics typically include quick pitches of software tools, methodologies, but fun topics are also game: I’ve seen a speed course Dutch, and a talk about coffee.
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6 ways to make your alerting less boring (and more effective!)

Posted by Joep Weijers on November 8, 2018

Imagine you are a developer and you have just pushed a change that breaks the build. The Continuous Integration system, Jenkins in our case, sends you an email to notify you about this failure. BORING! Here are six examples that you can use to spice up your alerting and motivate your Development and Operations teams to react to alerts faster.
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Pipelines: breaking the wall between Dev and Ops

Posted by Joep Weijers on October 11, 2017

At TOPdesk our Development department is working closely together with our Operations department. This collaboration started off a bit rough, but through several initiatives this was smoothed out. In this post I’d like to show how we used Deployment Pipelines to break down the wall between Development and Operations.

Put EVERYTHING in version control!

Posted by Joep Weijers on March 15, 2017

Screenshot of Revision History The whole software world is backed by Version Control Systems, providing history and traceability to code changes. But you don’t have to restrict its usage to code. Read on to learn how TOPdesk enjoys the benefits of a VCS by employing it in 5 alternative ways.

1. Documentation:

You want your documentation to live as close as possible to the code it describes. Putting your documentation right next to the code in a VCS allows you to keep both up to date. People who work with a certain revision are automatically presented with the relevant documentation for that version.
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