org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with t

org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session:

Hibernate经常用到的一个错误。解决的方法：

　1.将session清空一下，因为已经有一个ID一样的对象存在于内存中了。