Renan Huanca

Hello friends.

The first time when i was training to use spring and hibernate i wanted to avoid to open and close transaction manually in every method that does some transaction.

   i.e. (pseudo code)
       void createSomeObject(par1, par2, par3) {
           open transaccion
           create object using the given parameters
           persist the object
           close transaction
       }

So i found that spring helps you to do that.

I will assume that you already created the Java Bean (POJO) and it’s hibernate mapping file. ( SomePOJO.java and SomePOJO.hbm.xml files).

1. Define AOP and Transaction  namespace in spring application context configuration file. (Find more about AOP and Transaction Management)

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
       ... ...
</beans>

2. Define data source to configure the database connection parameters.

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
    <property name="driverClassName" value="org.postgresql.Driver"/>
    <property name="url" value="jdbc:postgresql://localhost/somedb"/>
    <property name="username" value="someuser"/>
    <property name="password" value="somepassword"/>
</bean>

3. Define Hibernate SessionFactory.

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="mappingResources">
        <list>
            <value>/some/package/model/SomePOJO.hbm.xml</value>
        </list>
    </property>
    <property name="hibernateProperties">
        <value>
            hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
        </value>
    </property>
</bean>

4. Define Transaction aspect. (more info)

<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory"/>
</bean>

<tx:advice id="txAdvice" transaction-manager="txManager">
    <tx:attributes>
        <tx:method name="*"/>
    </tx:attributes>
</tx:advice>

5. Define point cuts in your service.

<aop:config>
    <aop:pointcut id="someServiceMethods" expression="execution(* some.package.service.SomeService.*(..))"/>
    <aop:advisor advice-ref="txAdvice" pointcut-ref="someServiceMethods"/>
</aop:config>

Spring will begin a transaction each time a method in SomeService is called. This behavior can be changed (see) , I just tried to do the example the most simple as possible.

I will try to prepare some package with source code. just let me know.
Regards

-Renan

Renan Huanca Spring AOP, Hibernate, Spring