two open sessions异常
异常：
org.springframework.orm.hibernate3.HibernateSystemException: Illegal attempt to associate a collection with two open sessions; nested exception is org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessionsCaused by: org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessionsat org.hibernate.collection.AbstractPersistentCollection.setCurrentSession(AbstractPersistentCollection.java:410)at org.hibernate.event.def.OnUpdateVisitor.processCollection(OnUpdateVisitor.java:43)at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:101)at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:61)at org.hibernate.event.def.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:55)at org.hibernate.event.def.AbstractVisitor.process(AbstractVisitor.java:123)
?原因：
系统中同一业务处理过程中，一个Session中对象可能被另一个Session访问，且业务处理过程中同时开了两个session
解决办法：
关闭上一个Sessoin后再接着处理下一个Session的业务，或将 业务处理合并到同一个Session中
