我想做这样的事情：
我试图设置一个EmbededId，这将是logRequest的属性。这就是我遇到的问题。我没有来管理嵌入式ID。（http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity- mapping- identifier）
如果您对我应该怎么做有一个提示:)
一个示例（不起作用）将是：
@Entity @AssociationOverride( name="logRequest.fileName", joinColumns = { @JoinColumn(name="log_request_file_name") } ) public class Reporting { @EmbeddedId private ReportingFile logRequest; @CollectionOfElements(fetch = FetchType.EAGER) @JoinTable(name = "t_reports", schema="", joinColumns = {@JoinColumn(name = "log_report")}) @Fetch(FetchMode.SELECT) private List<ReportingFile> reports; @Column(name="generated_date",nullable=true) private Date generatedDate; [...] } @Embeddable public class ReportingFile { @Column(name="file_name",length=255) private String fileName; @Column(name="xml_content") private Clob xmlContent; [...] }
在此示例中，我有以下错误：
15.03.2010 16:37:59 [ERROR] org.springframework.web.context.ContextLoader Context initialization failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor#0' defined in class path resource [config/persistenceContext.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [config/persistenceContext.xml]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to configure EntityManagerFactory at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:480) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:881) at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:597) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:366) at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:255) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:45) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3843) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4350) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardHost.start(StandardHost.java:719) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443) at org.apache.catalina.core.StandardService.start(StandardService.java:516) at org.apache.catalina.core.StandardServer.start(StandardServer.java:710) at org.apache.catalina.startup.Catalina.start(Catalina.java:578) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413) Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [config/persistenceContext.xml]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to configure EntityManagerFactory at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1337) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:308) at org.springframework.beans.factory.BeanFactoryUtils.beansOfTypeIncludingAncestors(BeanFactoryUtils.java:270) at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.detectPersistenceExceptionTranslators(PersistenceExceptionTranslationInterceptor.java:122) at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.<init>(PersistenceExceptionTranslationInterceptor.java:78) at org.springframework.dao.annotation.PersistenceExceptionTranslationAdvisor.<init>(PersistenceExceptionTranslationAdvisor.java:70) at org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor.setBeanFactory(PersistenceExceptionTranslationPostProcessor.java:97) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1325) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473) ... 29 more Caused by: javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to configure EntityManagerFactory at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:265) at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:125) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83) at org.springframework.orm.jpa.LocalEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalEntityManagerFactoryBean.java:91) at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:291) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1368) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1334) ... 46 more Caused by: org.hibernate.AnnotationException: A Foreign key refering Reporting from Reporting has the wrong number of column. should be 2 at org.hibernate.cfg.annotations.TableBinder.bindFk(TableBinder.java:272) at org.hibernate.cfg.annotations.CollectionBinder.bindCollectionSecondPass(CollectionBinder.java:1319) at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1158) at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:600) at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:541) at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:43) at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1140) at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:319) at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1125) at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1226) at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:159) at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:854) at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:191) at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:253) ... 52 more
好的，我们等着瞧
您有一个@AssociationOverride注释，其API指出：
此批注用于 覆盖 实体关系的属性或字段 的多对一或一对一 映射。
和
它可以应用于 扩展映射超类的实体， 以覆盖该映射超类定义的多对一或一对一映射
我没有在您的问题中没有看到@ManyToOne和@OnoToOne。因此，您的问题出了点问题。
但是我已经在您的StackTrace中看到以下日志
从报表引用报表的外键列号错误。应该是2
您有一个 由@EmbeddedId批注定义 的复合主键 ，该批注具有两个属性（fileName和xmlContent）
现在，让我们看看您的@CollectionOfElements
@CollectionOfElements(fetch=FetchType.EAGER) @JoinTable(name="t_reports", // Your mistake goes here joinColumns=@JoinColumn(name="log_report")) @Fetch(FetchMode.SELECT) private List<ReportingFile> reports;
它的外键仅包含 一个属性， 而您的复合主键包含 两个属性 。 两者必须匹配 。它解释了为什么您看到此好消息
您正确的映射应如下所示
@CollectionOfElements(fetch=FetchType.EAGER) @JoinTable(name="t_reports", joinColumns={ // The number of columns defined by our Compound primary key (2) // must match the number of columns defined by its Foreign key (2) @JoinColumn(name="file_name", referencedColumnName="file_name"), @JoinColumn(name="xml_content", referencedColumnName="xml_content")}) @Fetch(FetchMode.SELECT) private List<ReportingFile> reports;
还有更多：我不知道您的目标数据库是否支持Clob作为主键。因此请记住这一点。
根据您的回复添加到原始答案
1º 第一种情况（ 不带 @CollectionOfElements）
@Entity public class Reporting { // You said you just want a single fileName as primary key @Id @Column(name="file_name", nullable=false) private String fileName; // You said you still want to have the whole ReportingFile object @Embedded private ReportingFile reportingFile; @Embeddable public static class ReportingFile implements Serializable { // You must set up insertable=false, updatable=false @Column(name="file_name", insertable=false, updatable=false) private String fileName; @Column(name="xml_content") private Clob xmlContent; } }
请记住以下几点：Hibernate 不允许您定义两个属性，它们都共享同一列 。因此，我必须在fileName属性中定义insertable = false，updatable = false。
当我执行以下操作时
Reporting reporting = new Reporting(); reporting.setFileName("home.pdf"); ReportingFile reportingFile = new ReportingFile(); // It will not persisted because of insertable=false, updatable=false reportingFile.setFileName("home.pdf"); reportingFile.setXmlContent(someClobObject); session.save(reporting); // It works
2º 第一种情况（ 带有 @CollectionOfElements）
@Entity public class Reporting { // You said you just want a single fileName as primary key @Id @Column(name="file_name", nullable=false) private String fileName; // You said you still want to have the whole ReportingFile object @Embedded private ReportingFile reportingFile; @CollectionOfElements(fetch=FetchType.EAGER) @JoinTable( name="t_reports", joinColumns=@JoinColumn(name="file_name", referencedColumnName="file_name", insertable=false, updatable=false)) private List<ReportingFile> reports; @Embeddable public static class ReportingFile implements Serializable { // You must set up insertable=false, updatable=false @Column(name="file_name", insertable=false, updatable=false) private String fileName; @Column(name="xml_content") private Clob xmlContent; } }
Reporting reporting = new Reporting(); reporting.setFileName("home.pdf"); ReportingFile reportingFile = new ReportingFile(); // It will not persisted because of insertable=false, updatable=false reportingFile.setFileName("home.pdf"); reportingFile.setXmlContent(someClobObject); reporting.getReports().add(reportingFile); session.save(reporting); // It does not work
hibernate会抱怨
映射中用于收集的重复列：报告列：file_name
因此，当您有一个@CollectionOfElements共享一个外键时， 它将无法按预期工作 。但是您可以采取解决方法
@Entity public class Reporting { // You said you just want a single fileName as primary key @Id @Column(name="file_name", nullable=false) private String fileName; // You said you still want to have the whole ReportingFile object @Embedded private ReportingFile reportingFile; // Your workaround goes here @CollectionOfElements(fetch=FetchType.EAGER) @JoinTable( name="t_reports", joinColumns=@JoinColumn(name="file_name", referencedColumnName="file_name")) private List<Clob> xmlContents; @Transient public List<ReportingFile> getReports() { List<ReportingFile> reports = new ArrayList<ReportingFile>(); for(Clob xmlContent: getXmlContents()) reports.add(new ReportingFile(getFileName(), xmlContent)); return reports; } @Embeddable public static class ReportingFile implements Serializable { // required no-arg constructor public ReportingFile() {} public ReportingFile(String fileName, Clob xmlContent) { this.fileName = fileName; this.xmlContent = xmlContent; } // You must set up insertable=false, updatable=false @Column(name="file_name", insertable=false, updatable=false) private String fileName; @Column(name="xml_content") private Clob xmlContent; } }
请注意，在自己的类内部使用时，可以将@Embeddable类定义为静态类。
