CODEWITHSUNDEEP
springentitymanager
Massimo Ugues
Massimo Ugues

Reputation: 4463

Spring @PersistenceContext how to inject manually the entity manager in my GenericDao

Hallo all: I read the spring reference about this point.

I would choose to use the @PersistenceContext in my DAO to inject a shared transactional entity manager, but since I use the GenericDaoJpaImpl pattern over two entityManagerFactories that point to 2 different persistence units I cannot use it.

So right now in my application I have this configuration:

entityManagerFactoryies:

<bean id="entityManagerFactoryIban0" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceXmlLocation" value="classpath:META-INF/contratto-persistence-iban0.xml" />
    </bean>

    <bean id="entityManagerFactoryCont0" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceXmlLocation" value="classpath:META-INF/contratto-persistence-cont0.xml" />
    </bean>

    <bean abstract="true" id="abstractDaoJpaImplIban0" lazy-init="false">
        <property name="entityManagerFactory" ref="entityManagerFactoryIban0" />
    </bean>

    <bean abstract="true" id="abstractDaoJpaImplCont0" lazy-init="false">
        <property name="entityManagerFactory" ref="entityManagerFactoryCont0" />
    </bean>

Then each of my DAOs is an instance of the GenericDaoImpl:

@Repository
public class GenericDaoJpaImpl<T, ID extends Serializable> implements GenericDao<T, ID> {
    private Class<T> entityClass;

    private EntityManagerFactory entityManagerFactory;

    public void setEntityManagerFactory(EntityManagerFactory entityManagerFactory) {
        this.entityManagerFactory = entityManagerFactory;
    }

    public GenericDaoJpaImpl() {
        super();
    }

    public GenericDaoJpaImpl(Class<T> entityClass) {
        super();
        this.entityClass = entityClass;
    }

    /**
     * @see it.alten.intesasanpaolo.contratto.dao.common.GenericDao#getItemByID(java.io.Serializable)
     */
    @Override
    public T getItemByID(ID id) {
        EntityManager em = entityManagerFactory.createEntityManager();
        return em.find(entityClass, id);

    }

I construct my dao via spring in this way:

<bean id="eventMessageDao" parent="abstractDaoJpaImplCont0" class="it.alten.intesasanpaolo.contratto.dao.common.GenericDaoJpaImpl">
        <constructor-arg>
            <value>it.alten.intesasanpaolo.contratto.domain.event.OnlineEventMessage</value>
        </constructor-arg>
    </bean>

Now I would like to modify the GenericDaoJpaImpl as described in the spring documentation not to be associated to the entityManagerFactory from which I have to create every time the entityManager but directly to the entityManager.

I would like to define it in the context in a way I can inject it to the correct abstract dao to be extended from every dao.

<bean abstract="true" id="abstractDaoJpaImplIban0" lazy-init="false">
        <property name="entityManagerFactory" ref="entityManagerFactoryIban0" />
    </bean>

How can I achieve this?

kind regards Massimo

Upvotes: 1

Views: 6850

Answers (2)

manikanta
manikanta

Reputation: 8500

You can provide the persistence unit name in the xml configuration, using the SharedEntityManagerBean, like below:

<bean id="testDao" class="com.test.persistence.dao.BaseDAO">
    <property name="entityManager">
        <bean class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
            <property name="persistenceUnitName" value="persistence-test-unit" />
        </bean>
    </property>
</bean>

of course, you can have the SharedEntityManagerBean as a separate bean

Here, I m injecting entityManager into BaseDAO as you're doing using @PersistenceContext(unitName="...")

Upvotes: 0

axtavt
axtavt

Reputation: 242686

You can use SharedEntityManagerBean to construct a transactional EntityManager from the EntityManagerFactory:

<bean id="entityManagerFactoryIban0" 
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">            
    ... 
</bean> 

<bean id="entityManagerIban0"  
    class="org.springframework.orm.jpa.support.SharedEntityManagerBean">            
    <property name="entityManagerFactory" ref="entityManagerFactoryIban0" />
</bean> 

<bean abstract="true" id="abstractDaoJpaImplIban0" lazy-init="false">
    <property name="entityManager" ref="entityManagerIban0" />
</bean>

Upvotes: 5

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