java - JPA 中带有 IN 子句的位置参数

Question

我正在尝试评估以下 JPQL 查询:

select err from Error err where err.errType = ? and err.msg in (?)

err.msg 是与派生自名为 CSMessage 的类的对象的关系。

所以我做了这样的事情:

...fetch my CSMessage from the DB. This part actually works...

List<CSMessage> msgList = new ArrayList<CSMessage>();
msgList.add(msg);

query.setParameter (1, new Long(0));
query.setParameter (2, msgList);

query.getResultList();

根据我的阅读，这应该没问题。但是，当我运行它时，我得到以下堆栈跟踪:

javax.persistence.PersistenceException: org.hibernate.HibernateException: Unable to resolve entity name from Class [java.util.LinkedList] expected instance/subclass of [domain.CSMessage]
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1235)
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1168)
    at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:250)
    at dao.impl.jpa.GenericJPADaoImpl.findAllUsingQuery(GenericJPADaoImpl.java:529)
    at dao.impl.jpa.GenericJPADaoImpl.findAllUsingJPQLQuery(GenericJPADaoImpl.java:476)
    at dao.impl.jpa.ErrorDaoImpl.findAllByTypeForMessages(ErrorDaoImpl.java:72)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:618)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
    at $Proxy36.findAllByTypeForMessages(Unknown Source)
    at dao.ErrorDaoTest.testFindAllByTypeForMessages(ErrorDaoTest.java:194)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:618)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:82)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:240)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:45)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: org.hibernate.HibernateException: Unable to resolve entity name from Class [java.util.LinkedList] expected instance/subclass of [domain.CSMessage]
    at org.hibernate.tuple.entity.PojoEntityTuplizer.determineConcreteSubclassEntityName(PojoEntityTuplizer.java:362)
    at org.hibernate.persister.entity.AbstractEntityPersister.getSubclassEntityPersister(AbstractEntityPersister.java:3918)
    at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1484)
    at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:203)
    at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:243)
    at org.hibernate.type.EntityType.getIdentifier(EntityType.java:449)
    at org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:142)
    at org.hibernate.param.PositionalParameterSpecification.bind(PositionalParameterSpecification.java:68)
    at org.hibernate.loader.hql.QueryLoader.bindParameterValues(QueryLoader.java:571)
    at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1632)
    at org.hibernate.loader.Loader.doQuery(Loader.java:717)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:270)
    at org.hibernate.loader.Loader.doList(Loader.java:2449)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2192)
    at org.hibernate.loader.Loader.list(Loader.java:2187)
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:452)
    at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363)
    at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1258)
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
    at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:241)
    ... 43 more

我很困惑。有人知道我做错了什么吗？

谢谢...

Answer 1

好吧，这只是我的一个愚蠢的错误。我使用 Hibernate 的查询语言有一段时间了，当我转向 JPA 时，我错过了 JPA 中位置参数不同的事实。

Hibernate 中的位置参数只使用 '?'就其本身而言，JPA 希望能够重用位置参数，因此参数应该类似于 '?#'，其中 # 是大于 1 的任何数字。

似乎如果您忘记了这些数字，JPA 会尝试做一些事情，并且在大多数情况下它工作得很好，但是当尝试将列表作为位置参数传递时，它会失败。在我看来，如果位置参数错误，查询解析器在解析查询时应该抛出异常，但它似乎并没有这样做。