春天 + GAE Spring容器初始化不正确

Question

我正在尝试编写一个使用 Spring + GAE 启用的 aoolication，但我遇到了一个非常奇怪的问题。

对于持久层，我使用带有以下 persistence.xml 文件的 JPA：

<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence 
                        http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" 
    version="1.0">

    <persistence-unit name="transactions-optional">
        <provider>org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider</provider>
        <properties>
            <property name="datanucleus.NontransactionalRead" value="true" />
            <property name="datanucleus.NontransactionalWrite" value="true" />
            <property name="datanucleus.ConnectionURL" value="appengine" />
        </properties>
    </persistence-unit>

</persistence>

另外，我还有带有以下声明的 spring 配置文件：

 <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

    <tx:annotation-driven />

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
        <property name="persistenceUnitName" value="transactions-optional" />
    </bean>

    <bean name="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

    <bean id="datastoreService" class="com.google.appengine.api.datastore.DatastoreServiceFactory" factory-method="getDatastoreService" />

    <bean id="memcacheServiceUser" class="com.google.appengine.api.memcache.MemcacheServiceFactory" factory-method="getMemcacheService">
        <constructor-arg value="UserCache"/>
    </bean> 

</beans>

最后，我有 DAO 组件，该组件被标记为 @Repository 并扩展了 JpaDaoSupport 这个配置为扫描的 bean

在尝试初始化该 DAO bean 后，我收到以下异常：

Caused by: java.lang.IllegalArgumentException: entityManagerFactory or jpaTemplate is required
at org.springframework.orm.jpa.support.JpaDaoSupport.checkDaoConfig(JpaDaoSupport.java:120)
at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$5.run(AbstractAutowireCapableBeanFactory.java:1467)
at java.security.AccessController.doPrivileged(Native Method)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1465)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
... 30 more

然后我查看了日志，可以看到entityManagerFactory 在 DAO init 之前成功创建，但就在 DAO 对象初始化实际开始之前，spring 只是销毁了所有单例，包括这个。有很多日志，但我确信entityManagerFactory也会创建，对我来说非常奇怪的一件事是为什么spring用以下日志消息销毁所有单例：

    INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1594a88: defining beans [org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,entityManagerFactory,transactionManager,datastoreService,memcacheServiceUser,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,userDaoJpa,employeeDS,messageSource]; root of factory hierarchy
Jan 14, 2011 11:12:12 AM org.springframework.beans.factory.support.DisposableBeanAdapter destroy
FINE: Invoking destroy() on bean with name 'entityManagerFactory'
Jan 14, 2011 11:12:12 AM org.springframework.orm.jpa.AbstractEntityManagerFactoryBean destroy
INFO: Closing JPA EntityManagerFactory for persistence unit 'transactions-optional'
Jan 14, 2011 11:12:12 AM org.springframework.web.context.ContextLoader initWebApplicationContext
SEVERE: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDaoJpa' defined in file 

Answer 1

JpaDaoSupport 类希望您在构造时设置 EntityManagerFactory 或 JpaTemplate 。像这样的事情应该这样做：

@Repository
public class YourDAOImpl extends JpaDaoSupport implements YourDAO
{
    @Autowired
    public YourDAOImpl(EntityManagerFactory entityManagerFactory)
    {
        setEntityManagerFactory(entityManagerFactory);
    }

    ...
}

Answer 2

您可以使用下面的方法自动注入实体管理器。

@PersistenceContext
private EntityManager entityManager;

Answer 3

@Autowired
public ClaseDaoImpl(EntityManagerFactory entityManagerFactory) {
    setEntityManagerFactory(entityManagerFactory);
}

各由道来实现。