I created a quite handy tool generating a Java class with all the constants stuff from the “/OH-INF” folder ("/ESH-INF" in older versions), because I hated to write those classes on my own. It’s time consuming and unsafe (typos, out of sync, …).
The plugin can be found here: https://github.com/kokuwaio/esh-constants-maven-plugin.
And of cause in the Maven central repository. Have fun and feel encouraged to give feedback.