JPATransactionManager and annotation driven transactions - jpa

Question

I've a small spring3/Hibernate JPA application running and I've come a cropper when trying to use Transactional annotations. Basically they are being ignored by the TransactionManager.
I have a save method that I've amended to highlight that the Transactional attribute readOnly is being ignored. Basically I would have figured that the persist call would have resulted in an exception being thrown because the readOnly attribute is set to true however this is not the case and the entity persists happily to an in-memory HSQLDB.
#Transactional(readOnly=true)
public Product save(Product product) throws HibernateException {
getEntityManager().persist(product);
return product;
}
The JPATransaction manager is wired as follows...
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="org.hsqldb.jdbcDriver" />
<property name="url" value="jdbc:hsqldb:mem:testdb;shutdown=false" />
<property name="username" value="sa" />
<property name="password" value="" />
</bean>
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" id="jpaProperties">
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<property name="searchSystemEnvironment" value="true" />
<property name="location" value="classpath:landingPage-hibernate.properties"/>
</bean>
<util:properties id="jpaHibernateProperties">
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.cache.provider_class">net.sf.ehcache.hibernate.EhCacheProvider</prop>
<prop key="hibernate.cache.use_query_cache">true</prop>
<prop key="hibernate.cache.use_second_level_cache">true</prop>
</util:properties>
<bean id="hibernateVendor" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="databasePlatform" value="${hibernate.dialect}"/>
<property name="showSql" value="${hibernate.show_sql}" />
<property name="generateDdl" value="${generateDdl}"/>
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="landingPagePersistence"/>
<property name="dataSource" ref="dataSource"/>
<property name="jpaVendorAdapter" ref="hibernateVendor"/>
<property name="jpaPropertyMap" ref="jpaHibernateProperties"/>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
Would anyone have an example of JPATransactionManager working with Transactional attributes or am I misunderstanding the usage of JPA entirely? I can see in the EntityManager constructor that the PersistenceContext is always EXTENDED as opposed to TRANSACTION which appears to have some bearing on whether or not the annotations are taken into consideration. Any help would be greatly appreciated.
Thanks,
Mark.

Answer 1

It's not a bug. It's a documented, expected behavior:
This just serves as a hint for the actual transaction subsystem; it will not necessarily cause failure of write access attempts. A transaction manager which cannot interpret the read-only hint will not throw an exception when asked for a read-only transaction.