org.hibernate.MappingException: Association references unmapped class: com.lj.zh

Caused by: org.hibernate.MappingException: Association references unmapped class: com.lj.zhang.Order
at org.hibernate.cfg.HbmBinder.bindCollectionSecondPass(HbmBinder.java:2521)
at org.hibernate.cfg.HbmBinder$CollectionSecondPass.secondPass(HbmBinder.java:2807)
at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:69)
at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1611)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1369)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1756)
at util.HibernateUtil.buildSessionFactory(HibernateUtil.java:19)
at util.HibernateUtil.<clinit>(HibernateUtil.java:13)
... 1 more



这个错误出现在

/**
	 * Called for all collections
	 */
	public static void bindCollectionSecondPass(Element node, Collection collection,
			java.util.Map persistentClasses, Mappings mappings, java.util.Map inheritedMetas)
			throws MappingException {

		if ( collection.isOneToMany() ) {
			OneToMany oneToMany = (OneToMany) collection.getElement();
			String assocClass = oneToMany.getReferencedEntityName();
			PersistentClass persistentClass = (PersistentClass) persistentClasses.get( assocClass );
			if ( persistentClass == null ) {
				throw new MappingException( "Association references unmapped class: " + assocClass );
			}
			oneToMany.setAssociatedClass( persistentClass );
			collection.setCollectionTable( persistentClass.getTable() );

			if ( LOG.isDebugEnabled() ) {
				LOG.debugf( "Mapping collection: %s -> %s", collection.getRole(), collection.getCollectionTable().getName() );
			}
		}

原因是我在User.hbm.xml中配置了One-to-many  ， class是Order.

可是Order这个对象的hbm.xml我并没有在hibernate.cfg.xml中配置。
也就是缺少了<mapping resource="Order.hbm.xml"/>
导致出错。


看来Hibernate会在启动时对这些进行很仔细的检查，
怪不得启动这么慢。