What plugin are you using to run the Java class? The Exec plugin? Could you post your plugin description from the pom.xml?
Also, you could try running with the -X option. The plugin should give you more information about what it is doing. And -X also caused Maven to dump the build plan, make sure your plugin's execution appears in the build plan.
Finally, if you want you class to run before unit tests, you have to set the plugin to run during the test-compile phase; that's the phase immediately before the test phase which is when the unit tests run.