%%%% 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.(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 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.
