I have a maven (multi-module) project that contains something like an IAction. In this project I have implemented about 50 implementation of different actions. Each Action consists of a MyAction.java and a MyAction.properties file.
I use Java's SPI (java.util.spi) to load all the implementations at runtime. This all works great, but now I want to package each Action into a single jar, so that I end up with 50 jars.
What would be a good way to accomplish this? I don't really want to create a sub-module for each action, as that takes a lot of maintenance.
You can use the Maven assembly plugin in order to create additional artifacts for building a module. However, note that you need to add these artifacts to your deployment queue once you created them, in case that you do not only want to build these artifacts. This can be achieved by for example using the build-helper-maven-plugin.
However, as for the iteration over 50 elements, you might want to consider writing your own specialized plugin. There are additional plugins that allow the iteration over another plugin, but this will blow up your POM. If a build is therefore very specific, you might therefore consider writing an individual plugin which is specialized on this task. You can do this in pure Java instead of XML and it is not as hard as it sounds. There is documentation and there are default APIs to Maven. And you can check the source code of the named plugins on how to achieve your requirements.