Using Spring as a JPA Container
- by sdoca
Hi,
I found this article which talks about using Spring as a JPA container:
http://java.sys-con.com/node/366275
I have never used Spring before this and am trying to make this work and hope someone can help me.
In the article it states that you need to annotate a Spring bean with @Transactional and methods/fields with @PersistenceContext in order to provide transaction support and to inject an entity manager.
Is there something the defines a bean as a "Spring Bean"? I have a bean class which implements CRUD operations on entities using generics:
@Transactional
public class GenericCrudServiceBean implements GenericCrudService
{
@PersistenceContext(unitName="MyData")
private EntityManager em;
@Override
@PersistenceContext
public <T> T create(T t)
{
em.persist(t);
return t;
}
@Override
@PersistenceContext
public <T> void delete(T t)
{
t = em.merge(t);
em.remove(t);
}
...
...
...
@Override
@PersistenceContext
public List<?> findWithNamedQuery(String queryName)
{
return em.createNamedQuery(queryName).getResultList();
}
}
Originally I only had this peristence context annotation:
@PersistenceContext(unitName="MyData")
private EntityManager em;
but had a null em when findWithNamedQuery was invoked. Then I annotated the methods as well, but em is still null (no injection?).
I was wondering if this had something to do with my bean not being recognized as "Spring".
I have done configuration as best I could following the directions in the article including setting the following in my context.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:tx="http://www.springframework.org/schema/tx"
tx:schemaLocation="http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="MyData" />
<property name="dataSource" ref="dataSource" />
<property name="loadTimeWeaver"
class="org.springframework.classloading.ReflectiveLoadTimeWeaver" />
<property name="jpaVendorAdapter" ref="jpaAdapter" />
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
<property name="url" value="jdbc:oracle:thin:@localhost:1521:MySID" />
<property name="username" value="user" />
<property name="password" value="password" />
<property name="initialSize" value="3" />
<property name="maxActive" value="10" />
</bean>
<bean id="jpaAdapter"
class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">
<property name="databasePlatform"
value="org.eclipse.persistence.platform.database.OraclePlatform" />
<property name="showSql" value="true" />
</bean>
<bean
class="org.springframework.ormmjpa.support.PersistenceAnnotationBeanPostProcessor" />
<tx:annotation-driven />
</beans>
I guessed that these belonged in the context.xml file because the article never specifically said which file is the "application context" file. If this is wrong, please let me know.
