Spring Hibernate Transaction Management

Question

I just started creating a project using spring and sleep. The DAO class class extends HibernateDaoSupport. We do not use annotations. We used to use struts, so we used the getTransaction, commit, rollback .. methods provided by the Session class. My requirement is very simple, for all DAO classes, if there is an exception, it rolls back otherwise. Please suggest the easiest way to introduce spring transaction management.

Answer 1

A few things are not clear from your question. My explanation is based on the following assumptions:

• You use spring to create a data source and a factory session
• You are using Java 5 or higher and can use annotations.

Here is what your spring configuration looks like.

<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="org.hsqldb.jdbcDriver" /> <property name="url" value="jdbc:hsqldb:hsql://localhost:9001" /> <property name="username" value="sa" /> <property name="password" value="" /> </bean> <bean id="mySessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <property name="dataSource" ref="myDataSource" /> <property name="mappingResources"> <list> <value>product.hbm.xml</value> </list> </property> <property name="hibernateProperties"> <value> hibernate.dialect=org.hibernate.dialect.HSQLDialect </value> </property> </bean> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="mySessionFactory" /> </bean> <tx:annotation-driven transaction-manager="transactionManager" /> 

Once this is set up, you can use spring transactional annotations for your DAO methods, as shown below. spring will take care of starting transactions, committing transactions, or discarding transactions when exceptions are thrown. If you have business services, ideally you would use transactional annotations for your services instead of DAOs.

 @Transactional(propagation=Propagation.REQUIRED) public class MyTestDao extends HibernateDaoSupport { public void saveEntity(Entity entity){ getHibernateTemplate().save(entity); } @Transactional(readOnly=true) public Entity getEntity(Integer id){ return getHibernateTemplate().get(Entity.class, id); } } 

The code below shows how transactions can be managed using spring support for AOP, not annotations.

  <!-- Define your 'myDatasource' bean and 'mySessionFactory' bean as shown in previous code snippet --> <!-- Then follow the steps shown below --> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="mySessionFactory" /> <!-- this is the dao object that we want to make transactional --> <bean id="testDao" class="com.xyz.daos.MyTestDao" /> <!-- the transactional advice --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <!-- all methods starting with 'get' are read-only --> <tx:method name="get*" read-only="true" /> <!-- other methods use the default transaction settings (see below) --> <tx:method name="*" propagation="REQUIRED" /> </tx:attributes> </tx:advice> <!-- ensure that the above transactional advice runs for any execution of a method in 'daos' package--> <aop:config> <aop:pointcut id="allDaoMethods" expression="execution(* com.xyz.daos.*(..))" /> <aop:advisor advice-ref="txAdvice" pointcut-ref="allDaoMethods" /> </aop:config> 

For more information, please, Spring Declarative Transactions