persistence.xml - spring JPA

Question

我已经读了几十篇文章，但我想不出错误在哪里……它应该非常简单。我正在尝试使用Spring和JPA在appengine上编写应用程序。

我正在使用JEE5项目(不知道这是否重要)

<tx:annotation-driven transaction-manager="transactionManager"/>

<bean id="persistenceUnitManager" class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
    <property name="persistenceXmlLocation">
        <value>classpath*:/META-INF/persistence.xml</value>
    </property>
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
    <property name="persistenceUnitName" value="transactions-optional" />
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor" />
<bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />

persistence.xml文件位于META-INF目录(根目录/META-INF/persistence.xml)中

<?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>

我仍然得到这个异常(我试图在src目录中移动meta-inf目录，但没有成功，异常是相同的)

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'genericJpaDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: protected javax.persistence.EntityManagerFactory cz.cvut.fel.pupilbook.dao.support.jpa.GenericJpaDAO.entityManagerfactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in ServletContext resource [/WEB-INF/context/applicationContext.xml]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: No Persistence provider for EntityManager named transactions-optional
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:844)

谢谢你的帮助。

Answer 1

anwer由两部分组成。

1. denisk关于persistence.xml的位置是正确的，它应该在src下。
2. 我遗漏了一些对datanucleus的依赖(我以为它们是提供的)。在添加它们之后，我得到了很多相关的异常。在解决了这些问题之后，一切都正常了。

所以-这是两个问题的巧合，每个问题都掩盖了另一个问题的一部分。