Mavenized merge of several plugins into a single jar file

Hi all,
with your help I have successfully implemented several ImageJ2 plugins, each is a single Maven project in a folder (e.g. ImageJPlugin1) with a corresponding pom file, src and target sub-folders. In Eclipse I can build each project and get the target jar files.
Additionally, I created a main pom file to build all plugins at once.



This pom creates each individual jar file in the appropriate target sub-folder.

However, now I would like to additionally create a single jar file that combines all these plugins, so that only one file is needed to be copied to the ImageJ or Fiji Plugins folder. Is this possible?

Any help is appreciated,