#Hibernate
doc http://docs.jboss.org/hibernate/orm/3.6/reference/zh-CN/html/
https://docs.jboss.org/hibernate/entitymanager/3.5/reference/en/html/transactions.html
example http://www.journaldev.com/3793/hibernate-tutorial-with-example-projects
oneToMany unidirectional http://blog.moove-it.com/jpa-onetomany-i-need-fk-child-table/
getCurrentSession & transaction http://myjourneyonjava.blogspot.com/2013/12/difference-between-opensession-and.html
http://javahonk.com/hibernateexception-no-session-found-for-current-thread/
https://technicalrecyclebin.wordpress.com/2014/10/12/org-hibernate-hibernateexception-no-session-found-for-current-thread/
Transaction propagation http://docs.spring.io/spring/docs/3.0.x/reference/transaction.html#tx-propagation