我对使用 spring 2.5 实现 jpa 的 openjpa 几乎没有问题。我的道法:
@Transactional
public User getUserByName(final String name) {
return (User) getEntityManager().createQuery("select u from User as u where u.name = :name").setParameter("name", name).getSingleResult();
}
返回 org.springframework.dao.InvalidDataAccessApiUsageException:
org.apache.openjpa.persistence.InvalidStateException: Detected reentrant flush. Make sure your flush-time instance callback methods or event listeners do not invoke any operations that require the in-progress flush to complete.
at org.apache.openjpa.kernel.BrokerImpl.flushSafe(BrokerImpl.java:1904)
at org.apache.openjpa.kernel.BrokerImpl.flush(BrokerImpl.java:1679)
at org.apache.openjpa.kernel.QueryImpl.isInMemory(QueryImpl.java:956)
at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:838)
at org.apache.openjpa.kernel.QueryImpl.execute(QueryImpl.java:779)
at org.apache.openjpa.kernel.DelegatingQuery.execute(DelegatingQuery.java:525)
at org.apache.openjpa.persistence.QueryImpl.execute(QueryImpl.java:254)
at org.apache.openjpa.persistence.QueryImpl.getSingleResult(QueryImpl.java:317)
at org.jpa.dao.UserDao.getUserByName(UserDao.java:71)
//编辑 EntityManager 设置:
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.OpenJpaVendorAdapter">
<property name="showSql" value="false"/>
</bean>
</property>
<property name="loadTimeWeaver">
<bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/>
</property>
<property name="jpaDialect">
<bean class="org.springframework.orm.jpa.vendor.OpenJpaDialect"/>
</property>
</bean>
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
如何获得 EntityManage?在 da 类中:
@PersistenceContext(type = PersistenceContextType.EXTENDED)
protected EntityManager entityManager;
怎么了?任何想法?