The Apache Maven team is pleased to announce the release of the Apache Maven JLink Plugin, version 3.1.0.
This plugin is used to create a JLink distribution using Maven. It is as easy as creating a jar file, but will instead create a zip file containing a reduced Java Runtime along with a launcher script, as well as the actual application of course. A JLink zip file is therefore platform dependent.
Whenever you pull in SnakeYAML (either directly or via Jackson), you will break your modulear builds. The reason: SnakeYAML is a named automatic module. But then, automatic modules cannot be used in jlink images.
But this can be healed. You can rescue your builds using the moditect-maven-plugin. It is a little hard to use, as the documentation is very technical. It also has few examples, and the documentation does not explain when to use which goal, and how to proceed. So, if you want to see a simple example, read on! 🙂
If you want to integration-test your Maven project, you might already use GitHub Actions.
Testing with a Maven toolchain is a little more complex to set up. This tutorial will show how I did this for the maven-jlink-plugin.
I recently created a new OpenPGP key for my Apache (ASF) account. Of course I wanted to sign it with my existing GnuPG key I have since 2007. To my surprise, it failed with these error messages:
gpg: Note: third-party key signatures using the SHA1 algorithm are rejected gpg: signing failed: Invalid digest algorithm gpg: signing failed: Invalid digest algorithm
It took me a few hours to figure out what’s wrong. Obviously something with SHA1, but GnuPG doesn’t tell you WHAT is wrong and HOW to fix it.
Have you ever wondered how your program will connect to other hosts?
Well, I can tell you the answer for Java (any version) and compare it to Python. It is a 90’s implementation, and there is not even a good way to fix it.
Here is a list of my top 10 OpenLiberty hidden features. They are not the “best” features by any means of »hidden knowledge«, but they are the most handy features I use regularly not everyone knows about. YMMV. 😉
Glowroot is a lightweighted but feature-rich java VM agent, which will allow you to collect and evaluate metrics from almost any VM. For larger setups, you might want to install a central collection instance. This guide covers how to set up Glowroot Central on OpenLiberty, a lightweigt and extremely fast Java Application Server (aka Servlet Container).
The java application server OpenLiberty will receive support for Certificates issued by Let’s Encrypt. The setup will be ridiculously easy as always. You can just paste the following lines into your server.xml ein:
Json-B (not JSONB!), short for Json Binding, is a modern MicroProfile Java standard to convert json documents (json messages) to a java class and vice versa.
This standard is supported by most modern java application containers. But because of a definition gap in the Jax-RS standard, it is not as easy as initially thought to get proper and helpful error messages if an invalid JSON document is encountered in the POST request body of an endpoint. The ExceptionMapper will only work after applying a few tricks.
I just finished a new project: A social bot for Twitter. It’s name is @BotZodiac, it’s purpose to twitter the current zodiac sign status. Of…
