%%%% Error Creating SessionFactory %%%%
org.hibernate.MappingException: duplicate property mapping: customer
at org.hibernate.mapping.PersistentClass.checkPropertyDuplication(PersistentClass.java:414)
at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:404)
at org.hibernate.mapping.RootClass.validate(RootClass.java:192)
at org.hibernate.cfg.Configuration.validate(Configuration.java:984)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1169)
at com.sily.hib.HibernateSessionFactory.<clinit>(HibernateSessionFactory.java:31)
at com.sily.hib.dao.BaseHibernateDAO.getSession(BaseHibernateDAO.java:15)
at com.sily.hib.dao.OrdersDAO.saveCustomerAndOrder(OrdersDAO.java:144)
at com.sily.hib.dao.OrdersDAO.main(OrdersDAO.java:173)
%%%% Error Creating SessionFactory %%%%
org.hibernate.MappingException: Could not read mappings from resource: com/sily/hib/po/Usr.hbm.xml
at org.hibernate.cfg.Configuration.addResource(Configuration.java:485)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1465)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1433)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1414)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1390)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1310)
at com.sily.hib.HibernateSessionFactory.rebuildSessionFactory(HibernateSessionFactory.java:69)
at com.sily.hib.HibernateSessionFactory.getSession(HibernateSessionFactory.java:53)
at com.sily.hib.dao.BaseHibernateDAO.getSession(BaseHibernateDAO.java:15)
at com.sily.hib.dao.OrdersDAO.saveCustomerAndOrder(OrdersDAO.java:144)
at com.sily.hib.dao.OrdersDAO.main(OrdersDAO.java:173)
Caused by: org.hibernate.DuplicateMappingException: Duplicate class/entity mapping com.sily.hib.po.Usr
at org.hibernate.cfg.Mappings.addClass(Mappings.java:118)
at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:154)
at org.hibernate.cfg.Configuration.add(Configuration.java:386)
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:427)
at org.hibernate.cfg.Configuration.addResource(Configuration.java:482)
… 10 more
java.lang.NullPointerException
at com.sily.hib.dao.OrdersDAO.saveCustomerAndOrder(OrdersDAO.java:146)
at com.sily.hib.dao.OrdersDAO.main(OrdersDAO.java:173)
end.

重复的属性映射关系.报的错是customer,其实不是customer.hbm.xml的配置重复,而是与cumstomer有映射关系的另一个orders.hbm.xml配置中出现了重复,把重复去掉就行了.

我的问题出现的原因:软件自动生成了映射关系， 而自己还去配置了一个， 所以出错了.出错的时候,是在做一对多的关系,所以说,当时是做的一个customer对应多个orders,在orders.hbm.xml中出现的重复是
<many-to-one name=“customer” not-null=“true”
cascade=“all”>
<column name=“customer_id”></column>
</many-to-one>
这个语句写了俩次.去掉一个就行了.我想报的错应该就是红色的标记这个地方.