Hibernate3 Duplicate class/entity Mapping (Exception)

Hibernate3 Duplicate class/entity Mapping (Exception) code:
Configuration config = new configuration (). addclass (User.class). Buildsessionfactory ();

Workaround:
Remove the red code.
Reason: Sessionfactory = Config.configure (). Buildsessionfactory (), has read the configuration once,

(It will conflict with Hibernate.cfg.xml <mapping resource= "Cn/hbm/collections/user.hbm.xml"/>)

In Config.addclass (Medicine.class), the configuration is read again at execution time. So there is a org.hibernate.DuplicateMappingException exception. or hibernate.cfg.xml <mapping resource= "cn/hbm/collections/ User.hbm.xml "/>

Hibernate3 Duplicate class/entity Mapping (Exception)