If you are new to hibernate4-maven-plugin, in many cases, the {Configuration-Method-Precedence} may be the source of configuration errors. To solve this problem, you should run maven with the debugging output enabled. For example, by executing:

mvn -X compile hibernate4:export

(The compile might be necessary, because hibernate4-maven-plugin has to scan the compiled classes for annotations!)

Unlike the majority of the maven-plugins, hibernate4-maven-plugin was designed to give a good many hints, when debugging is enabled. Because, if you do not know, what went wrong, you can't fix it!

But be warned: hibernate4-maven-plugin tends to be very chatty ;)