HIbernate JPA由与javassist.util.proxy.proxy不兼容引起

Question

HIbernate JPA与javassist.util.proxy.Proxy不兼容导致。

代码

public class EntityA {
@Id
private String id;
@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "entityB_id")
private EntityB entityB;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "entityC_id")
private EntityC entityC;
}
String sql = "select o from EntityA o "
+ "left outer join o.entityB as o1 ";
final TypedQuery<EntityA> query = getEm().createQuery(sql, EntityA.class);
final List<EntityA> result = query.getResultList();

问题

当运行上面的查询会得到下面的异常，有人知道吗？

我的查询没有涉及"EntityC"，为什么在getResultList()方法中会抛出关于EntityC的异常？

异常

Caused by: java.lang.ClassCastException: xxx.xx.xx.EntityC_$$_javassist_105 incompatible with javassist.util.proxy.Proxy
at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.getProxy(JavassistLazyInitializer.java:148)
at org.hibernate.proxy.pojo.javassist.JavassistProxyFactory.getProxy(JavassistProxyFactory.java:73)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.createProxy(AbstractEntityTuplizer.java:758)
at org.hibernate.persister.entity.AbstractEntityPersister.createProxy(AbstractEntityPersister.java:4419)
at org.hibernate.event.internal.DefaultLoadEventListener.createProxyIfNecessary(DefaultLoadEventListener.java:334)
at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:260)
at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:152)
at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1053)
at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:980)
at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:714)
at org.hibernate.type.EntityType.resolve(EntityType.java:502)
at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:168)
at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:137)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1112)
at org.hibernate.loader.Loader.processResultSet(Loader.java:969)
at org.hibernate.loader.Loader.doQuery(Loader.java:917)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:348)
at org.hibernate.loader.Loader.doList(Loader.java:2550)
at org.hibernate.loader.Loader.doList(Loader.java:2536)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2366)
at org.hibernate.loader.Loader.list(Loader.java:2361)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:495)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:357)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:198)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1230)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:268)
at sun.reflect.GeneratedMethodAccessor213.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:56)
at java.lang.reflect.Method.invoke(Method.java:620)
at org.springframework.orm.jpa.SharedEntityManagerCreator$DeferredQueryInvocationHandler.invoke(SharedEntityManagerCreator.java:368)
at com.sun.proxy.$Proxy153.getResultList(Unknown Source)
at com.cimb.module.payment.bill.ce.dao.CEMYCCPayeeAccessBean.findNormalByPayeeNameKeyword(CEMYCCPayeeAccessBean.java:59)
at com.cimb.module.payment.bill.atom.RetrieveBillerByKeywordMYAtom.performNormalBillerSearch(RetrieveBillerByKeywordMYAtom.java:58)
at com.cimb.module.payment.bill.atom.RetrieveBillerByKeywordMYAtom.proceedNextStep(RetrieveBillerByKeywordMYAtom.java:45)
at core.logic.DefaultLogicProcessor.process(DefaultLogicProcessor.java:78)
... 94 more

Answer 1

好的，我也遇到过这个问题。经过一些研究，以下是我的结论：

1. javassist太旧或丢失对于旧的Spring版本，您必须添加/更新您的javassist。您可以从Maven存储库获取最新信息。链接到这里！

2. 如果您遇到org.hibernate.LazyInitializationException: could not initialize proxy - no Session错误，则是由于您在连接关闭后试图进行延迟加载。您可能需要在服务/控制器中添加@Transactional注释(取决于项目的设计)，无论是类级别还是方法级别。