You just need to insert CVS tags somewhere in your comments. A good place is at the start of each class, e.g.:
/**
* This is my superb class that does everything including making my laundry ...
*
* @version $Revision: $ ($Date: $)
* @author $Author: $
*/
The CVS tags "$...$" will automatically be extended/updated when you check in the file. For all CVS keywords, see http://ximbiot.com/cvs/wiki/index.php?title=CVS--Concurrent_Versions_System_v1.12.12.1:_Keyword_substitution