2011-06-01 55 views
1

Hallo全部: 我读过关于这一点的spring参考。Spring @PersistenceContext如何在我的GenericDao中手动注入实体管理器

我会选择在我的DAO中使用@PersistenceContext来注入一个共享的事务性实体管理器,但由于我在两个指向2个不同持久性单元的entityManagerFactories上使用GenericDaoJpaImpl模式,因此我无法使用它。

所以,现在在我的应用我有这样的配置:

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> 

然后我的每一个的DAO的是GenericDaoImpl的一个实例:我构建

@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); 

    } 

我通过这种方式弹簧:

<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> 

现在我想修改GenericDaoJpaImpl,如在spring文档中所描述的那样,不要关联到entityManagerFactory,我不得不每次创建entityManager而直接关联到entityManager。

我想以一种方式在上下文中定义它,我可以将它注入正确的抽象道,以便从每道道扩展。

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

我该如何做到这一点?

亲切的问候 马西莫

回答

4

您可以使用SharedEntityManagerBeanEntityManagerFactory构建事务EntityManager

<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> 
0

您可以在XML配置文件提供持久性单元名称,使用SharedEntityManagerBean,如下所示:

<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> 
当然

,你可以有SharedEntityManagerBean作为一个单独的bean

在这里,我米注射entityManagerBaseDAO为你使用做@PersistenceContext(unitName="...")

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