In Maven, I would turn this into three projects: common, domain, web. The first two would each build a jar and place it into the local repository, and the last would build a war and use those jars. In addition, I would use the standard Maven directory structure for each project.
But you can change the default directory locations for things:
Note that other plugins might also need or assume these locations so there might be other things you have to change also. That is why I stick to the default locations. [ July 24, 2008: Message edited by: Peter Johnson ]