我想做那样的事情：
>一个对象ReportingFile,可以是LogRequest或LogReport文件. (两者都有相同的结构)
>一个对象报告包含一个logRequest,一个带有日期的logReport列表.
我试着设置一个EmbededId,这将是logRequest的一个属性.这就是我遇到的问题.我没有到达mannage嵌入式id. (http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-mapping-identifier)
如果你有一个关于我应该怎么做的线索:)
一个例子(不工作)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
解决方法
好的,我们等着瞧
你有一个@AssociationOverride注释,它的API说：
This annotation is used to override a many-to-one or one-to-one mapping of property or field for an entity relationship.
和
It may be applied to an entity that extends a mapped superclass to override a many-to-one or one-to-one mapping defined by the mapped superclass
在你的问题中,我既没有看过@ManyToOne也没看过@OnoToOne.所以,你的问题有问题.
但是我在StackTrace中看到了以下日志
A Foreign key refering Reporting from Reporting has the wrong number of column. should be 2
你有一个由@EmbeddedId注释定义的复合主键,它有两个属性(fileName和xmlContent)
现在,让我们看看你的@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;
它的外键只包含一个属性,而您的复合主键包含两个属性.两者都必须匹配.它解释了为什么你看到这个好消息
A Foreign key refering Reporting from Reporting has the wrong number of column. should be 2
您的正确映射应如下所示
@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.所以记住它.
1º第一种情况(没有@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;
@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;
}
}
请记住以下内容：Hibernate不允许您定义两个共享同一列的属性.因此,我必须在fileName属性中定义insertable = false,updatable = false.
当我做以下事情
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(使用@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",updatable=false))
private List<ReportingFile> reports;
@Embeddable
public static class ReportingFile implements Serializable {
// You must set up insertable=false,updatable=false)
private String fileName;
@Column(name="xml_content")
private Clob xmlContent;
}
}
当我做以下事情
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
repeated column in mapping for collection: reports column: file_name
因此,当您拥有共享外键的@CollectionOfElements时,它将无法按预期工作.但你可以做一个解决方法
@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",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)
private String fileName;
@Column(name="xml_content")
private Clob xmlContent;
}
}
请注意,在您拥有的类中使用时,您可以将@Embeddable类定义为静态.
