Discriminator,WrongClassException JPA和Hibernate后端

我需要一个抽象的超类。

我有6个子类用于该抽象超类。

我使用JPA中的SINGLE_TABLEinheritance策略映射它们。

在另一个POJO中,我与这些1 + 6类有一对多的关系。

@OneToMany(mappedBy = "mSearchPreference", cascade = CascadeType.ALL) private Set mSearchCriteria; 

这里“SearchCriteria”是抽象类。

 @Entity @Table(name = "SRCH_CRTR_T", schema = "LPEW") @Inheritance(strategy=InheritanceType.SINGLE_TABLE) @DiscriminatorColumn(name = "SRCH_DISCRIMINATOR_CDE", discriminatorType = DiscriminatorType.STRING) @org.hibernate.annotations.ForceDiscriminator public abstract class SearchCriteria extends BaseDBObject implements Comparable 

它有6个具体的子类类

 @Entity @DiscriminatorValue("DATE") @Inheritance(strategy=InheritanceType.SINGLE_TABLE) public class SearchCriteriaDateRange extends SearchCriteria 

我可以将值插入表中,但是当我检索时出现错误:

 Caused by: org.hibernate.WrongClassException: Object with id: 261 was not of the specified subclass: com.lmig.lit.lpew.model.criteria.SearchCriteria (Discriminator: DATE ) at org.hibernate.loader.Loader.getInstanceClass(Loader.java:1453) at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1284) at org.hibernate.loader.Loader.getRow(Loader.java:1206) at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:580) at org.hibernate.loader.L 10:57:44,786 INFO [STDOUT] oader.doQuery(Loader.java:701) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) at org.hibernate.loader.Loader.loadCollection(Loader.java:1994) at org.hibernate.loader.collection.BatchingCollectionInitializer.initialize(BatchingCollectionInitializer.java:52) at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:565) at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:63) at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1716) at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:344) at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:86) at org.hibernate.collection.AbstractPersistentCollection.readElementExistence(AbstractPersistentCollection.java:142) at org.hibernate.collection.PersistentSet.add(PersistentSet.java:187) at com.lmig.lit.lpew.model.homescreen.HomeScreenPreference.addSearchCriteriaByType(HomeScreenPreference.java:132) at com.lmig.lit.lpew.model.homescreen.HomeScreenPreference.addSearchCriteriaByType(HomeScreenPreference.java:147) at com.lmig.lit.lpew.service.LpewUserServiceImpl.initializeHomeScreenPreferences(LpewUserServiceImpl.java:135) at com.lmig.lit.lpew.service.LpewUserServiceImpl.findUserAndInitialize(LpewUserServiceImpl.java:103) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) at $Proxy122.findUserAndInitialize(Unknown Source) at com.lmig.lit.lpew.jsf.beans.UserSession.getLpewUser(UserSession.java:989) at com.lmig.lit.lpew.jsf.beans.RequestForServiceBean.getAllRequests(RequestForServiceBean.java:263) at com.lmig.lit.lpew.jsf.beans.RequestForServiceBean.getAllNewRequests(RequestForServiceBean.java:382) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at javax.el.BeanELResolver.getValue(BeanELResolver.java:62) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:53) at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:64) at org.apache.el.parser.AstValue.getValue(AstValue.java:97) at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186) 

有谁知道解决方案?

你应该在你的根实体上使用@org.hibernate.annotations.DiscriminatorOptions(force=true)

如果您正在加载一组SearchCriteria enities,那么您的堆栈跟踪就像是一样。

例如:@OneToMany(mappedBy =“mSearchPreference”,cascade = CascadeType.ALL)private Set mSearchCriteria;

问题是Hibernate在没有加载实体的情况下无法知道正确的子类。 因此,如果通过延迟加载创建集合,则hibernate首先为集合中的所有实体创建类型为SearchCriteria的代理。 如果稍后加载了concreate实例,则无法通过正确的代理交换非concreate足够的代理。

因此,“修复”是不使用代理。 这意味着您必须使用预先加载(lazy =“false”)或lazy =“no-proxy”。 后一个选项需要对编译类进行字节代码操作,以使Hibernate拦截对getter方法的调用(参见http://www.hibernate.org/hib_docs/v3/re … properties)。 我没有这种方法的经验,但它似乎是你的情况的一个很好的候选人。

https://forum.hibernate.org/viewtopic.php?f=1&t=996047&start=0