使Spring使用DataNucleus (Spring )(Spring)

Question

有几个提示表明Spring数据与一起工作，如：

• http://tommysiu.blogspot.com/2014/01/spring-data-on-gae-part-1.html
• http://blog.eisele.net/2009/07/spring-300m3-on-google-appengine-with.html

很多例子都不是"Spring“，所以我一直试图用它来改造一些东西。然而，我已经被这个错误困扰了好几天了：

[INFO] Caused by: java.lang.NullPointerException
[INFO]  at org.datanucleus.api.jpa.metamodel.SingularAttributeImpl.isVersion(SingularAttributeImpl.java:79)
[INFO]  at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.findVersionAttribute(JpaMetamodelEntityInformation.java:102)
[INFO]  at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.<init>(JpaMetamodelEntityInformation.java:79)
[INFO]  at org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getMetadata(JpaEntityInformationSupport.java:65)
[INFO]  at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation(JpaRepositoryFactory.java:149)
[INFO]  at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:88)
[INFO]  at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:68)
[INFO]  at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:158)
[INFO]  at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:224)
[INFO]  at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:210)
[INFO]  at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:92)
[INFO]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$6.run(AbstractAutowireCapableBeanFactory.java:1602)
[INFO]  at java.security.AccessController.doPrivileged(Native Method)
[INFO]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1599)
[INFO]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1549)
[INFO]  ... 40 more

在这里，我试图在DataNucleus/AppEngine中使用Spring：

@Configuration
@ComponentScan
@EnableJpaRepositories
@EnableTransactionManagement
class JpaApplicationConfig {
    private static final Logger logger = Logger
            .getLogger(JpaApplicationConfig.class.getName());
    @Bean
    public EntityManagerFactory entityManagerFactory() {
        logger.info("Loading Entity Manager...");
        return Persistence
                .createEntityManagerFactory("transactions-optional");
    }

    @Bean
    public PlatformTransactionManager transactionManager() {
        logger.info("Loading Transaction Manager...");
        final JpaTransactionManager txManager = new JpaTransactionManager();
        txManager.setEntityManagerFactory(entityManagerFactory());
        return txManager;
    }
}

我已经测试了Persistence.createEntityManagerFactory("transactions-optional");，看看这个应用程序是否可以使用这个EMF，嗯，它确实存在，所以我确信这个EMF工作得很好。问题是与Spring数据JPA“连接”，有人能帮忙吗？

Answer 1

您的意思是这个问题http://www.datanucleus.org/servlet/jira/browse/NUCJPA-250，因为这似乎是很久以前就已经解决了。显然，您必须得到一个GAE版本，它将与您的JPA提供程序的那个版本一起工作。

Answer 2

另一个解决方法是切换回SpringData1.3.0。

如果您不想浪费一天时间配置Spring上下文和依赖项，我建议您这样做。