java Spring数据JPA注入失败BeanCreationException:无法自动连接字段
我按照发布的教程here获得了一个使用Spring数据JPA的基础应用程序。现在,我如何理解,使用配置
<jpa:repositories base-package="my.package.to.scan" />
应该导致SpringDataJPA扫描扩展JpaRepository
接口的包,并创建它的concreatebean,这样它就可以使用简单的Spring @Autowired
在我的服务类中的任何地方使用。但是它失败了,说它找不到具有className的bean(这是bean在创建时获得的默认名称,只需使用取消大写的className)
但是,当我在applicationContext中手动配置bean时,如下所示:
<bean id="ClassName" class="my.package.to.scan.ClassName"/>
春天能找到豆子。然后我当然会得到一个错误,因为我想从一个接口创建一个bean,这显然无法工作。但关键是Spring数据JPA“自动创建bean”似乎以某种方式失败了
我附上了相关的代码,你可以看看。顺便说一句,我应该提到我正在开发一个portlet,所以不要奇怪为什么我没有一个spring配置。我目前只使用applicationConfig和MyPortlet。用于portlet配置的xml(但这与此问题无关)。我添加导入语句只是为了确保我没有使用错误的注释/类
applicationContext。xml
<beans *** ALL MY XMLN's and XSI's *** />
<context:annotation-config />
<jpa:repositories base-package="model.repositories" />
// JPA specific configuration here: dataSource, persistenceUnitManager exceptionTranslator, entityManagerFactory, SessionFactory, transactionManager - should not be relevant for this problem, tell me if i'm wrong
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
ICCustomerService-只是CustomerService的一个接口
import model.entities.Customer;
public interface ICustomerService {
// example method
public Customer getCustomer(Long customerId);
}
CustomerService—我的应用程序逻辑用于获取/设置ORM数据的类
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import model.entities.Customer;
import model.repositories.CustomerRepository;
import model.service.interfaces.ICustomerService;
@Repository
@Transactional(readOnly = true)
public class CustomerService implements ICustomerService{
@Autowired
private CustomerRepository repository;
// example method
@Override
public Customer getCustomer(Long customerId){
return repository.findById(customerId);
}
CustomerRepository-Spring数据JPA的存储库
import javax.annotation.Resource;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.transaction.annotation.Transactional;
import model.entities.Customer;
@Resource
@Transactional(readOnly = true)
public interface CustomerRepository extends JpaRepository<Customer, Long>{
public Customer findById(Long id);
}
客户-我的样本实体
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "Customers")
public class Customer{
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name = "ID_CUSTOMER")
private Long id;
@Column(name = "dbfirstname")
private String firstName;
@Column(name = "dbname")
private String lastName;
public Long getId(){
return id;
}
public String getFirstName(){
return firstName;
}
public void setFirstName(String firstName){
this.firstName = firstName;
}
public String getLastName(){
return lastName;
}
public void setLastName(String lastName){
this.lastName = lastName;
}
}
我刚从类路径地狱来到WebSphere(该死的,这是一个多么复杂的产品),现在我在这里。希望有人能帮我
一个基本的解释是什么出了问题,也许提供一个更好的理解弹簧自动连接注射功能将是伟大的。我已经阅读了spring文档,但说实话:有太多的方法来配置某些东西,而在选择一种配置样式时,我并不清楚真正需要什么
编辑
在尝试更新项目后,我仍然得到错误。根据此处的要求,提供更多详细信息(跟踪):
Exception created : org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private model.repositories.CustomerRepository model.service.CustomerService.repository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerRepository': FactoryBean threw exception on object creation; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
[...]
at com.ibm.ws.http.HttpConnection.run(HttpConnection.java:522)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1563)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private model.repositories.CustomerRepository model.service.CustomerService.repository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerRepository': FactoryBean threw exception on object creation; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:506)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
... 96 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customerRepository': FactoryBean threw exception on object creation; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:149)
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:102)
at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1442)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:248)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:848)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:790)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:707)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:478)
... 98 more
Caused by: java.lang.NullPointerException
at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.getStatus(JtaStatusHelper.java:73)
at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.isActive(JtaStatusHelper.java:115)
at org.hibernate.engine.transaction.internal.jta.CMTTransaction.join(CMTTransaction.java:149)
at org.hibernate.ejb.AbstractEntityManagerImpl.joinTransaction(AbstractEntityManagerImpl.java:1215)
at org.hibernate.ejb.AbstractEntityManagerImpl.postInit(AbstractEntityManagerImpl.java:177)
at org.hibernate.ejb.EntityManagerImpl.<init>(EntityManagerImpl.java:89)
at org.hibernate.ejb.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:179)
at org.hibernate.ejb.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:174)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:600)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.invokeProxyMethod(AbstractEntityManagerFactoryBean.java:376)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean$ManagedEntityManagerFactoryInvocationHandler.invoke(AbstractEntityManagerFactoryBean.java:517)
at $Proxy325.createEntityManager(Unknown Source)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:234)
at $Proxy328.createNamedQuery(Unknown Source)
at org.springframework.data.jpa.repository.query.NamedQuery.<init>(NamedQuery.java:74)
at org.springframework.data.jpa.repository.query.NamedQuery.lookupFrom(NamedQuery.java:96)
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$DeclaredQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:128)
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:71)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:303)
at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:157)
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:120)
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.getObject(RepositoryFactoryBeanSupport.java:39)
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:142)
编辑#2 完成应用程序上下文。xml(包括我根据正在进行的讨论所做的更改)按要求添加
<context:annotation-config />
<jpa:repositories base-package="model.repositories" />
<context:component-scan base-package="model,model.repositories,model.service,controller" />
<bean class="model.service.CustomerService"/>
<bean class="model.service.OrderService"/>
<bean class="model.repositories.CustomerRepository"/>
<bean class="model.repositories.OrderRepository"/>
<bean id="myExceptionTranslator" class="org.springframework.orm.hibernate4.HibernateExceptionTranslator" />
<jee:jndi-lookup id="dataSource" jndi-name="jdbc/mydata"
resource-ref="true" cache="true" />
<bean id="pum"
class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
<property name="persistenceXmlLocations">
<list>
<value>classpath*:META-INF/OverridePersistence.xml</value>
</list>
</property>
<property name="defaultDataSource" ref="dataSource" />
</bean>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="generateDdl" value="true" />
<property name="database" value="MYSQL" />
</bean>
</property>
<property name="persistenceUnitManager" ref="pum" />
<property name="persistenceUnitName" value="default" />
</bean>
<bean id="mySessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="model"/>
<property name="hibernateProperties">
<value>hibernate.dialect=org.hibernate.dialect.MySQLDialect</value>
</property>
</bean>
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
<property name="sessionFactory" ref="mySessionFactory" />
</bean>
<tx:annotation-driven />
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
# 1 楼答案
问题很可能出现在您尚未显示的某些配置中。如果你发布了你收到的错误,这也会很好。它可能和你想象的不一样
关于您的配置,我注意到的一点是您使用的是
context:annotation-config
而不是context:component-scan
。后者将基于@Component
注释族自动检测和创建bean。前者不能做到这一点除此之外,您发布的所有内容看起来都应该是有效的,尽管有一些奇怪的事情,我稍后会谈到。我将您发布的所有代码复制到一个示例项目中,并填写了一些细节,如amaven pom、apersistence.xml,以及缺失的the applicationContext.xml。我还向服务中添加了一个“create”方法,这样它实际上可以做一些事情。有了这些,并有一个主类来驱动这一切,这是一个可运行的示例。您可以browse the code on github,也可以克隆并使用以下工具运行它:
现在来看看我注意到的奇怪之处。从顶部开始:
applicationContext.xml
中的^{@Repository
注释是supposed to be used on DAO classes,或与数据库交互的类。服务的适当注释是^{@Resource
注释主要是used for marking fields and methods for autowiring。我不确定是什么让你想到把它放在你的存储库界面上,但它没有做任何事情李>@Transactional
。这是你的服务,你已经拿到了,所以没关系。请注意,它仍然与存储库上的@Transactional
一起工作,因为它只是加入由服务启动的现有事务李>@Component
相关的注释(服务上的@Repository
)。这可能会给你带来一些问题。我没有打开组件扫描,而是在示例项目中使用XML手动创建了服务bean李>所以。。。如果这还没有向你解释什么,如果你给我一个具体的错误,我可能会解释为什么你会得到它,并告诉你怎么做,使它正确