我有一个抽象父类(super class)的要求。

对于那个抽象父类(super class)，我有 6 个子类。

我用 JPA 中的 SINGLE_TABLE 继承策略映射了它们。

在另一个 POJO 中，我与这 1+6 个类有一对多的关系。

@OneToMany(mappedBy = "mSearchPreference", cascade = CascadeType.ALL)
private Set<SearchCriteria> 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<SearchCriteria>

它有 6 个具体的子类，如

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

我可以将值插入表中，但在检索时出现错误:

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)

有人知道解决办法吗？

最佳答案

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

关于java - 鉴别器，带有 Hibernate 后端的 WrongClassException JPA，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/4334197/