包的层次结构应该是什么?
com.xyz.DAO
IDAO (interface)
IPersonDAO (interface)
IDepartmentDAO (interface)
com.xyx.DAO.impl
PersonDAO extends GenericDAO implements IPersonDAO
DepartmentDAO extends GenericDAO implements DepartmentDAO
GenericDAO implements IDAO (abstract class)
DAOFactory
这个包结构合适吗?