Jonathan Lalou's Blog

Case

You have a couple of Hibernate DAOs, in which a huge amount of code is duplicated: begin transactions, try/catch, close transactions, etc.
You would like to factorize your code.

Fix

• Define a SessionFactory, let’s say hibernateSessionFactory, with your own settings.

  [xml]<bean id="hibernateSessionFactory"
  class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">(…)</bean>[/xml]

• Define a TransactionManager:

  [xml]<bean id="hibernateTransactionManager"
  class="org.springframework.orm.hibernate3.HibernateTransactionManager">
  <property name="sessionFactory">
  <ref local="hibernateSessionFactory" />
  </property>
  </bean>[/xml]

• Define transactions advices:

  [xml]<tx:advice id="hibTxManager" transaction-manager="hibernateTransactionManager">
  <tx:attributes>
  <tx:method name="*" propagation="NEVER" read-only="true" isolation="READ_COMMITTED" rollback-for="find*" no-rollback-for="dontFind*"/>
  </tx:attributes>
  </tx:advice>[/xml]

• name="*" –> the aspect will apply to all methods. You may filter on patterns such as find*, get*, save*, etc.
• propagation="NEVER" –> hints the propagation level. Available options are
• REQUIRED, SUPPORTS, MANDATORY,REQUIRES_NEW, NOT_SUPPORTED, NEVER, NESTED.
• isolation="READ_COMMITTED" –>
• rollback-for="find*" –> rollback all transactions following the given pattern
• no-rollback-for="dontFind*" –> exceptions for rollbacks
• Define the AOP configuration:

  [xml]<aop:config>
  <aop:pointcut id="hibOperation"
  expression="execution(* com.lalou.jonathan.dao.hibernate.Hibernate*.*(..))" />
  <aop:advisor pointcut-ref="hibOperation" advice-ref="hibTxManager" />
  </aop:config>[/xml]

Many thanks to Jean-Pierre ISOARD for his help on this subject.