初始化Spring数据存储库时出现NullPointerException

时间：2014-03-25 14:48:48

标签： java spring hibernate jpa spring-data

我有使用Spring，Hibernate / JPA和Spring Data的webapp。我创建了扩展JpaRepository以获取某些权限的存储库，一切都很好用默认方法，如.save（T）或saveAndFlush，findAll，甚至使用findBy，如果某些字段名称简单为id（findById）或findByRole - 其中Role是枚举或findByActive，其中active是给定实体中的布尔字段。 但是当我尝试对复杂对象的字段做同样的事情时，我遇到了麻烦。我有一个名为Person的enetity。人有场

  

私人用户经理;

getter / setters。当我尝试将它放在PersonRepository中时：

public interface PersonRepository extends JpaRepository<Person, Long> {

    List<Person> findByManager(User manager);
}

我在应用部署期间遇到异常：

Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'PersonRepository': Invocation of init method failed; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1512)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:296)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:293)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:610)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:389)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:294)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:112)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4973)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1740)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:618)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:565)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1420)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
    at sun.rmi.transport.Transport$1.run(Transport.java:177)
    at sun.rmi.transport.Transport$1.run(Transport.java:174)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
    at org.springframework.data.jpa.repository.query.QueryUtils.getOrCreateJoin(QueryUtils.java:522)
    at org.springframework.data.jpa.repository.query.QueryUtils.toExpressionRecursively(QueryUtils.java:459)
    at org.springframework.data.jpa.repository.query.JpaQueryCreator$PredicateBuilder.build(JpaQueryCreator.java:199)
    at org.springframework.data.jpa.repository.query.JpaQueryCreator.toPredicate(JpaQueryCreator.java:146)
    at org.springframework.data.jpa.repository.query.JpaQueryCreator.create(JpaQueryCreator.java:86)
    at org.springframework.data.jpa.repository.query.JpaQueryCreator.create(JpaQueryCreator.java:44)
    at org.springframework.data.repository.query.parser.AbstractQueryCreator.createCriteria(AbstractQueryCreator.java:109)
    at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:88)
    at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:73)
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$QueryPreparer.<init>(PartTreeJpaQuery.java:98)
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery$CountQueryPreparer.<init>(PartTreeJpaQuery.java:186)
    at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:60)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:91)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:162)
    at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:69)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:304)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:161)
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:224)
    at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:210)
    at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:84)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1571)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1509)
    ... 55 more

我甚至尝试过类似：findByManagerId(Lond id);和其他一些组合，都是一样的。有任何想法吗？

从我的pom.xml导入部件：

 <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>3.5.1-Final</version>
        </dependency>
   <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.5.1.RELEASE</version>
        </dependency>

2 个答案:

答案 0 :(得分：2)

这解决了我的问题（在app init期间不知道NullPointerException是什么东西），但无论如何，这有助于（在我的PersonRepository中）：

@Query("SELECT person from Person person where person.manager=:manager")
public List<Person> findByManager(@Param("manager")User manager);

并节省了我的一天......我仍然认为这应该没有查询，NPE看起来像一个bug。谢谢你们！

答案 1 :(得分：0)

这并没有直接回答您获取空指针的原因，但您可以尝试为该查询创建自定义实现。阅读this documentation的1.3，了解如何做到这一点。

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