弹簧数据 JPA - 注入失败 - BeanCreation例外：无法自动布线字段
2022-09-02 13:25:40
我按照这里发布的教程获取了一个基础应用程序来使用Spring Data JPA。现在，我如何理解，使用配置
<jpa:repositories base-package="my.package.to.scan" />
应该导致Spring Data JPA扫描的该软件包用于接口扩展并创建它的创建bean，以便可以使用简单的Spring在我的服务类中的任何位置使用它。但它失败了，说它找不到带有className的bean（这是bean在创建时获得的默认名称，只需使用去大写的ClassName）。JpaRepository@Autowired
但是，当我在我的应用程序中配置bean手动时，如下所示：
<bean id="ClassName" class="my.package.to.scan.ClassName"/>
春天能够找到豆子。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，这显然不起作用。但关键是，似乎Spring Data JPA“自动豆子创建”似乎以某种方式失败了。
我附上了相关的代码，所以你可以看看它。顺便说一句，我应该提到我正在开发一个portlet，所以不要怀疑为什么我没有spring-config。我目前只使用一个 applicationConfig 和一个 MyPortlet-Portlet.xml用于 portlet 配置（但这不应该与此问题相关）。我添加导入语句只是为了确保我没有使用错误的注释/类。
应用上下文.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" />
ICustomerService - 只是客户服务的一个接口
import model.entities.Customer;
public interface ICustomerService {
// example method
public Customer getCustomer(Long customerId);
}
客户服务 - 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);
}
客户存储库 - Spring Data 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;
}
}
我只是来自WebSphere的classpath地狱（该死的，多么愚蠢的产品），现在我在这里。希望有人能帮我这个。
对严重出错的原因进行基本解释，也许可以更好地了解弹簧自动布线注射功能会很棒。我已经阅读了spring文档，但说实话：有很多方法可以配置某些东西，对我来说，在选择一种配置样式时，它并不是很清楚真正需要什么。
编辑
尝试更新项目后，我仍然收到错误。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完整的应用程序上下文.xml（包括我根据正在进行的讨论所做的更改）根据要求添加
<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" />
