Maarten on IT

last update:

This site started as a list of personal notes, interesting findings or whatsoever. Over time, I’m adding content that more looks like a regular blog. Either way, I hope you’ll find it useful. If so, drop me a line, I’d love to hear it! Feel free to get in touch; for options, see the right pane.

Build your own OpenJDK on macOS

— Maarten Mulders

Following the recent kerfuffle around the security manager deprecation, I was curious to see if a codebase I’m working on would also suffer. But how could I find out? There are no early access builds of Java 17 yet with the latest changes for this JEP. Maybe… I should set out and try to build it myself? But that’s sure going to be a lot of work… Or is it?

Introduction to Maven Toolchains

— Maarten Mulders

Java evolves at a much faster pace than it used to do. But not all of the projects we work on keep up with that pace. I have projects on Java 8, 11 and 15 - and sometimes I want to play with early access builds of newer versions as well. How to make sure I can build them without having to constantly switch Java runtimes?

Use git bisect to pinpoint a bug

— Maarten Mulders

During my work on Maven today, I found a very specific bug. The error message wasn’t that clear, and I couldn’t make a guess what might’ve caused it. I read about git bisect a few times and figured that today, I would use that tool to find the bug.

What's New in Maven 4

— Maarten Mulders & Martin Kanters

Recently, the Maven community decided to push forward and start working towards a 4.0.0 release. The first question after this announcement is of course: what can we expect Maven 4 to bring us? A lot - and in this post, we want to highlight some of the features that we are particularly excited about.

Block misbehaving IP addresses using Fail2Ban and AbuseIPDB

— Maarten Mulders

When you operate servers, whether physical or virtual, at some point in time you may find yourself victim to bots or botnets trying to access your server over SSH. Even if you configure your server to not expose SSH on port 22 (the default), chances are you will be a target at some point. This is especially true if your server is hosted in a public cloud, since these typically reserve ranges or blocks of IP addresses. Apart from making it as hard as possible to scan your server, you can also serve the community and report those attacks.