Spring integration: transactional method, read only flag not working

[martin.ahrer]

I'm trying to utilize Spring managed transactions using Springs @Transactional annotation. Methods that are supposed to read data only also carry the read only flag.
In order to test that this is working I created a method that tries to break this.

It executes a entitymanager.merge() operation. Surprisingly the data is written to the database even though the method is marked read only. Just right after the merge() operation it seems that the hibernate session/persistence context is flushed. As far as I know Spring is setting the flush mode MANUAL for read only marked methods.
Also I have marked the Seam methods with flush mode MANUAL!

I'm not sure if I'm doing something fundamentally wrong. I would appreciate any hints on that!

Here is the hibernate config (from persistence.xml)

<property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver" />
<property name="hibernate.connection.username" value="sa" />
<property name="hibernate.connection.autocommit" value="false" />
<property name="hibernate.connection.url" value="jdbc:hsqldb:mem:pac" />
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" />
<property name="hibernate.transaction.manager_lookup_class"
     value="org.hibernate.transaction.JBossTransactionManagerLookup" />
<property name="hibernate.hbm2ddl.auto" value="update" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.use_sql_comments" value="true" />
<property name="hibernate.format_sql" value="true" />
<property name="hibernate.connection.default_schema" value="DBO" />
<property name="hibernate.transaction.flush_before_completion" value="false"/>

Seam is configured in components.xml

<core:init debug="true"  transaction-management-enabled="false" />
<spring:context-loader config-locations="classpath:/beans/seamContext.xml" />
<persistence:managed-persistence-context name="entityManager" auto-create="true"
     entity-manager-factory="#{entityManagerFactorySpring}" />
<transaction:no-transaction />

So as you see Seam is not responsible for handling transactions at all!

The spring stuff is configured

<context:annotation-config />
<tx:annotation-driven proxy-target-class="true"/>

<seam:configure-scopes />

<!-- The entity manager factory that will be used to hand off entity managers to Spring based components-->
<bean id="entityManagerFactory"
     class="org.jboss.seam.ioc.spring.SeamManagedEntityManagerFactoryBean">
     <property name="persistenceContextName" value="entityManager" />
</bean>

<!-- The entity manager factory provided to Seam for creating a seam managed entity manager factory -->
<bean id="entityManagerFactorySpring"
     class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
     p:persistenceUnitName="pac" p:persistenceProviderClass="org.hibernate.ejb.HibernatePersistence">
     <property name="persistenceUnitManager">
          <bean
               class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
               <property name="persistenceXmlLocations"
                    value="classpath*:META-INF/persistence.xml" />
          </bean>
     </property>
</bean>

<!-- The transaction manager -->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
     <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

     
     
The seam component that invokes the transactional method looks as     

@Create
@Begin(flushMode = FlushModeType.MANUAL, join = false)
public void create() {
     return;
}

@Conversational
public String createPersonWithReadOnlyTransaction() {
     ...
     comp.saveWithReadOnlyTransaction(person);
     ...
     return "SUCCESS";
}     

     
And the transactional method

@Transactional(readOnly=true)
public Person saveWithReadOnlyTransaction(Person person) {
     return getJpaTemplate().merge(person);
}