Well, definitely, we cannot access a class being processed because at the same time it is being compiled.
And there is no way to run the annotation processor after the compilation round.
Then I searched in maven and spot the phase: process-classes
It is executed just after the compilation succeed, so it is perfect for my needs. During this phase I execute a java class that reads the xml file I have generated during the annotation processing. At this point I can access everything !
HIH