Question

我的基于java的配置是

@Configuration
@ComponentScan(basePackages = { "com.doly.jproject" })
@EnableTransactionManagement 
@EnableJpaRepositories (basePackages = "com.doly.jproject.repository")
public class RootConfigurer extends WebMvcConfigurerAdapter {   

    private Properties jpaProperties;   

    @Bean
    public DriverManagerDataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost/dbga");
        dataSource.setUsername("root");
        dataSource.setPassword("");
        return dataSource;
    } 

    @Bean
    public EntityManagerFactory entityManagerFactory() throws SQLException {

        LocalContainerEntityManagerFactoryBean entityManagerFactory = 
                new LocalContainerEntityManagerFactoryBean();
        entityManagerFactory.setPackagesToScan("com.doly.jproject.entity");
        entityManagerFactory.setDataSource(dataSource());

        jpaProperties = new Properties();       
        jpaProperties.put("hibernate.show_sql", true);
        jpaProperties.put("hibernate.hbm2ddl.auto", "create");

        entityManagerFactory.setJpaProperties(jpaProperties);
        entityManagerFactory.setPersistenceProvider(new HibernatePersistenceProvider());

        return entityManagerFactory.getObject();
    }


    @Bean
    @Qualifier(value = "entityManager")
    public EntityManager entityManager(EntityManagerFactory entityManagerFactory) {
        return entityManagerFactory.createEntityManager();
    }

    @Bean
    public JpaTransactionManager transactionManager() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setDataSource(dataSource());
        return transactionManager;
    }
}

但当我想在@Service类中将org.hibernate.Session的{{1}}对象初始化为

时

javax.persistence.EntityManager

我得到错误+ stacktrace为

@Autowired
@Qualifier(value = "entityManager")
private EntityManager entityManager;    
private Session session = entityManager.unwrap(org.hibernate.Session.class);

和SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.service.VidService com.doly.jproject.controllers.HomeController.vidService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidService' defined in file [F:\Spring Workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\jobsnetwork\WEB-INF\classes\com\doly\jproject\service\VidService.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.doly.jproject.service.VidService]: Constructor threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1210) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480) at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:5014) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5528) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.service.VidService com.doly.jproject.controllers.HomeController.vidService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidService' defined in file [F:\Spring Workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\jobsnetwork\WEB-INF\classes\com\doly\jproject\service\VidService.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.doly.jproject.service.VidService]: Constructor threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:561) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ... 22 more Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.service.VidService com.doly.jproject.controllers.HomeController.vidService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidService' defined in file [F:\Spring Workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\jobsnetwork\WEB-INF\classes\com\doly\jproject\service\VidService.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.doly.jproject.service.VidService]: Constructor threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1101) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1120) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1044) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:942) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533) ... 24 more Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.doly.jproject.service.JobService]: Constructor threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1094) ... 35 more Caused by: java.lang.NullPointerException at com.doly.jproject.service.VidService.<init>(VidService.java:42) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147) ... 37 more是

和

com.doly.jproject.service.VidService.<init>(VidService.java:42)

更新当我改变

public void updateJobCategory(Video video) {
        Video video = (Video)session.get(Video.class, id);// Here it causes com.doly.jproject.service.VidService.<init>(VidService.java:42)
video.getCustomers().clear();//removes all the existing customers
Customer customer1 = new Customer();
customer1.getVideos().add(video)//adding video to the customer
video.getCustomers().add(customer1);
session.update(video)


    }

在更新方法中我写

@Autowired
    @Qualifier(value = "entityManager")
    private EntityManager entityManager;    
    private Session session;

我得到了

public void updateJobCategory(Video video) {
    session= entityManager.unwrap(org.hibernate.Session.class);
    Video video = (Video)session.get(Video.class, id);
    video.getCustomers().clear();//removes all the existing customers
    Customer customer1 = new Customer();
    customer1.getVideos().add(video)//adding video to the customer
    video.getCustomers().add(customer1);
    session.update(video)


        }

如何在@Service类中从SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.service.VidService com.doly.jproject.controllers.HomeController.vidService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.repository.VidRepository com.doly.jproject.VidService.vidRepository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidRepository': Cannot create inner bean '(inner bean)#681afbff' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#681afbff': Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1210) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480) at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:5014) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5528) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.service.VidService com.doly.jproject.controllers.HomeController.vidService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.repository.VidRepository com.doly.jproject.service.VidService.vidRepository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidRepository': Cannot create inner bean '(inner bean)#681afbff' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#681afbff': Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:561) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ... 22 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.rhcloud.jobsnetwork.repository.JobRepository com.doly.jproject.service.VidService.vidRepository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidRepository': Cannot create inner bean '(inner bean)#681afbff' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#681afbff': Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1210) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1120) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1044) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:942) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533) ... 24 more Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.doly.jproject.repository.VidRepository com.doly.jproject.service.VidService.vidRepository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidRepository': Cannot create inner bean '(inner bean)#681afbff' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#681afbff': Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:561) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ... 35 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vidRepository': Cannot create inner bean '(inner bean)#681afbff' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#681afbff': Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:313) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1477) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1222) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1120) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1044) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:942) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533) ... 37 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#681afbff': Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1119) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1014) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:299) ... 50 more Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.persistence.EntityManager]: Factory method 'createSharedEntityManager' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) ... 55 more Caused by: java.lang.NullPointerException at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.initProxyClassLoader(SharedEntityManagerCreator.java:198) at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.<init>(SharedEntityManagerCreator.java:190) at org.springframework.orm.jpa.SharedEntityManagerCreator.createSharedEntityManager(SharedEntityManagerCreator.java:162) at org.springframework.orm.jpa.SharedEntityManagerCreator.createSharedEntityManager(SharedEntityManagerCreator.java:119) at org.springframework.orm.jpa.SharedEntityManagerCreator.createSharedEntityManager(SharedEntityManagerCreator.java:91) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ... 56 more获取org.hibernate.Session的一部分？请帮忙！

Answer 1

这对我来说似乎有问题：

@Autowired
@Qualifier(value = "entityManager")
private EntityManager entityManager;    
private Session session = entityManager.unwrap(org.hibernate.Session.class);

在构造对象后发生自动装配。这意味着当您的服务被创建时，它将尝试在实体管理器设置之前调用entityManager.unwrap。

此外，保存会话通常不是一种好习惯。您应该为您执行的每个操作/事务创建一个新的EntityManager / Session。你配置的方式，在你的应用程序的生命周期中只有一个EntityManager bean，这将导致问题。你可能想要什么：

@Autowired
private EntityManagerFactory entityManagerFactory;

然后

public void doStuff() {
    EntityManager entityManager = entityManagerFactory.createEntityManager();
}

由于您已经在使用Spring，因此您可能还需要查看@Transactional注释。

无法实例化bean构造函数引发异常;嵌套异常是java.lang.NullPointerException

1 个答案: