Question

我正在升级到Hibernate 4.3.8，我在单元测试中遇到了一个奇怪的问题。

我有一个引用语言类

的User类

public class User{
   @ManyToOne(cascade=CascadeType.MERGE,optional = true, fetch=FetchType.EAGER)
   @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
   @Fetch(FetchMode.SELECT)
   private Language language;

   @Column
   @NaturalId(mutable=false)
   private String email;

}

@Entity
@Immutable
@Cache(usage=CacheConcurrencyStrategy.READ_ONLY)
@NaturalIdCache(region=CacheRegion.NATURAL)
public class Language{

}

因此，在升级之后，我开始看到这个异常，因为用户类是这样加载的：

    User user = (User) getSessionFactory().getCurrentSession()
    .bySimpleNaturalId(User.class)
    .load(email);

例外：

java.lang.UnsupportedOperationException: Can't write to a readonly object
    at org.hibernate.cache.ehcache.internal.strategy.ReadOnlyEhcacheEntityRegionAccessStrategy.update(ReadOnlyEhcacheEntityRegionAccessStrategy.java:115)
    at org.hibernate.cache.ehcache.internal.nonstop.NonstopAwareEntityRegionAccessStrategy.update(NonstopAwareEntityRegionAccessStrategy.java:216)
    at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:211)
    at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:144)
    at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.performTwoPhaseLoad(AbstractRowReader.java:244)
    at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishUp(AbstractRowReader.java:215)
    at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractResults(ResultSetProcessorImpl.java:140)
    at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:138)
    at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:102)
    at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.load(AbstractLoadPlanBasedEntityLoader.java:186)
    at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:4126)
    at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:503)
    at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:468)
    at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:213)
    at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:275)
    at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:151)
    at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1070)
    at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:989)
    at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:716)
    at org.hibernate.type.EntityType.resolve(EntityType.java:502)
    at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:170)
    at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:144)
    at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.performTwoPhaseLoad(AbstractRowReader.java:244)
    at org.hibernate.loader.plan.exec.process.internal.AbstractRowReader.finishUp(AbstractRowReader.java:215)
    at org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl.extractResults(ResultSetProcessorImpl.java:140)
    at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:138)
    at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:102)
    at org.hibernate.loader.entity.plan.AbstractLoadPlanBasedEntityLoader.load(AbstractLoadPlanBasedEntityLoader.java:186)
    at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:4126)
    at org.hibernate.event.internal.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:503)
    at org.hibernate.event.internal.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:468)
    at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:213)
    at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:275)
    at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:151)
    at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1070)
    at org.hibernate.internal.SessionImpl.access$2000(SessionImpl.java:176)
    at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.load(SessionImpl.java:2551)
    at org.hibernate.internal.SessionImpl$SimpleNaturalIdLoadAccessImpl.load(SessionImpl.java:2794)

这里有什么建议吗？

Answer 1

所以，这似乎是因为在某个地方，当涉及到缓存时，Hibernate开始处理在相同事务中创建的对象与在不同事务中创建的对象不同。

因此，如果你有一个单元测试，你在创建只读对象的事务中进行一些设置，即使你只写了一次，如果它们是在与测试相同的事务中创建的，它们将抛出异常。

解决方案是使用带有Propagation.REQUIRES_NEW的事务管理器，在中央方法中创建一次只读对象。你不能为此使用注释，BTW

休眠升级后无法写入只读对象

1 个答案: