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Re: [eclipselink-users] EntityManager.find returning instance of wrong type
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Also, just looking at the code sample you provided:
Long aId = 76576; // a valid id for an entity of type Bar
Foo foo = em.find(Foo.class, aId); // em is EntityManager
Why would you not just do the following if you're expecting a Bar object:
Bar bar = em.find(Bar.class, aId);
?? I think the ClassCastException that you're getting is the right behaviour.
On Sun, Mar 8, 2009 at 10:36 AM, Zarar Siddiqi <zarars@xxxxxxxxx> wrote:
> Currently you've got
> @Inheritance(strategy=InheritanceType.SINGLE_TABLE) on the subclasses,
> try putting them ONLY on the base class.
>
>
>
> On Sun, Mar 8, 2009 at 6:50 AM, jsw <marvin.438@xxxxxxxxx> wrote:
>>
>> If I've understood correctly, when the DiscriminatorColumn annotation is
>> missing JPA defaults to DTYPE (with values corresponding to the entity
>> name). Just to be sure I tried adding the DiscriminatorColumn annotation to
>> the Base class and DiscriminatorValue annotations to the subclasses (I had
>> already moved the Inheritance from the deriving clases to the Base class)
>> but it made no difference: the problem persists.
>>
>>
>>
>> Zarar Siddiqi wrote:
>>>
>>> How would JPA know what row coincides with what subclass? To tell it
>>> that you'll need to use the @DiscriminatorColumn on the parent class
>>> and supply a unique value for each subclass using the
>>> @DiscriminatorValue for the subclasses.
>>>
>>> Also, the @Inheritance(strategy=InheritanceType.SINGLE_TABLE)
>>> annotation goes on the parent class.
>>>
>>> Zarar
>>>
>>>
>>> On Fri, Mar 6, 2009 at 8:52 AM, jsw <marvin.438@xxxxxxxxx> wrote:
>>>>
>>>> In my REST service:
>>>>
>>>> public void doTest() {
>>>> long id = 12; // valid id of Bar entity
>>>>
>>>> List<Base> bases = this.facade.getDAO().findAllBase();
>>>>
>>>> Base base = null;
>>>> try {
>>>> if ((base = this.facade.getWorkOrderDAO().findFooById(id)) !=
>>>> null) { // this row will throw an exception
>>>> log.debug("Found Foo");
>>>> } else if ((base =
>>>> this.facade.getWorkOrderDAO().findBarById(id)) != null) {
>>>> log.debug("Found Bar");
>>>> }
>>>>
>>>> } catch (Exception ex) {
>>>> ex.printStackTrace();
>>>> }
>>>> }
>>>>
>>>> And in the DAO class:
>>>>
>>>> @Transactional(readOnly = true, propagation=Propagation.SUPPORTS)
>>>> public List<Base> findAllBase() {
>>>> return em.createQuery("select b from Base b").getResultList();
>>>> }
>>>>
>>>> @Transactional(readOnly = true, propagation=Propagation.SUPPORTS)
>>>> public Foo findFooById(long id) {
>>>> return em.find(Foo.class, id);
>>>> }
>>>>
>>>> @Transactional(readOnly = true, propagation=Propagation.SUPPORTS)
>>>> public Bar findBarById(long id) {
>>>> return em.find(Bar.class, id);
>>>> }
>>>>
>>>> java.lang.ClassCastException: com.acme.planning.dataaccess.model.Bar
>>>> cannot
>>>> be cast to com.acme.planning.dataaccess.model.Foo
>>>> at com.acme.planning.dataaccess.DAO.findFooById(DAO.java:348)
>>>> at
>>>> com.acme.planning.dataaccess.DAO$$FastClassByCGLIB$$80c0e135.invoke(<generated>)
>>>> at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:191)
>>>> at
>>>> org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:700)
>>>> at
>>>> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
>>>> at
>>>> org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
>>>> at
>>>> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
>>>> at
>>>> org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:635)
>>>> at
>>>> com.acme.planning.dataaccess.DAO$$EnhancerByCGLIB$$93a24725.findFooById(<generated>)
>>>> at
>>>> com.acme.planning.interaction.rest.MobilogService.test(MobilogService.java:829)
>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>> at
>>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
>>>> at
>>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
>>>> at java.lang.reflect.Method.invoke(Method.java:597)
>>>> at
>>>> com.sun.jersey.server.impl.model.method.dispatch.EntityParamDispatchProvider$ResponseOutInvoker._dispatch(EntityParamDispatchProvider.java:157)
>>>> at
>>>> com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:67)
>>>> at
>>>> com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:154)
>>>> at
>>>> com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:111)
>>>> at
>>>> com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:71)
>>>> at
>>>> com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:111)
>>>> at
>>>> com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:63)
>>>> at
>>>> com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:543)
>>>> at
>>>> com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:502)
>>>> at
>>>> com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:493)
>>>> at
>>>> com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:308)
>>>> at
>>>> com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:314)
>>>> at
>>>> com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:239)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
>>>> at
>>>> com.acme.common.filter.CacheControlFilter.doFilter(CacheControlFilter.java:72)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378)
>>>> at
>>>> org.springframework.security.intercept.web.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)
>>>> at
>>>> org.springframework.security.intercept.web.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.ui.SessionFixationProtectionFilter.doFilterHttp(SessionFixationProtectionFilter.java:67)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.ui.ExceptionTranslationFilter.doFilterHttp(ExceptionTranslationFilter.java:101)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.providers.anonymous.AnonymousProcessingFilter.doFilterHttp(AnonymousProcessingFilter.java:105)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.wrapper.SecurityContextHolderAwareRequestFilter.doFilterHttp(SecurityContextHolderAwareRequestFilter.java:91)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.ui.basicauth.BasicProcessingFilter.doFilterHttp(BasicProcessingFilter.java:174)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.ui.AbstractProcessingFilter.doFilterHttp(AbstractProcessingFilter.java:277)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.ui.logout.LogoutFilter.doFilterHttp(LogoutFilter.java:89)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.context.HttpSessionContextIntegrationFilter.doFilterHttp(HttpSessionContextIntegrationFilter.java:235)
>>>> at
>>>> org.springframework.security.ui.SpringSecurityFilter.doFilter(SpringSecurityFilter.java:53)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:390)
>>>> at
>>>> org.springframework.security.util.FilterChainProxy.doFilter(FilterChainProxy.java:175)
>>>> at
>>>> org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:236)
>>>> at
>>>> org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
>>>> at
>>>> org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
>>>> at
>>>> org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
>>>> at
>>>> org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
>>>> at
>>>> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
>>>> at
>>>> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
>>>> at
>>>> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
>>>> at
>>>> org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
>>>> at
>>>> org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
>>>> at
>>>> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
>>>> at
>>>> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
>>>> at
>>>> org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
>>>> at
>>>> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
>>>> at
>>>> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
>>>> at
>>>> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
>>>> at
>>>> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
>>>> at
>>>> org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
>>>> at java.lang.Thread.run(Thread.java:619)
>>>>
>>>>
>>>> tch wrote:
>>>>>
>>>>> Doesn't sound right, can you post the whole stack trace?
>>>>>
>>>>> ./tch
>>>>>
>>>>>
>>>>>
>>>>> On Fri, Mar 6, 2009 at 7:56 AM, jsw <marvin.438@xxxxxxxxx> wrote:
>>>>>>
>>>>>> OK, thank you, it seems I had misunderstood how to use the @Inheritance
>>>>>> annotation. However, in this case it does not seem to make a difference
>>>>>> since SINGLE_TABLE is the default inheritance type.
>>>>>>
>>>>>> Unfortunately, moving the @Inherintance annotation to the base class
>>>>>> did
>>>>>> not
>>>>>> solve my problem. EntityManager.find keeps trying to return an instance
>>>>>> of
>>>>>> the wrong entity.
>>>>>>
>>>>>> Maybe something more I've misunderstood?
>>>>>>
>>>>>>
>>>>>>
>>>>>> tch wrote:
>>>>>>>
>>>>>>> I've never used the @Inheritance annotation, but I believe it goes on
>>>>>>> the base class, not the extending entity.
>>>>>>>
>>>>>>> See:
>>>>>>> http://www.oracle.com/technology/products/ias/toplink/jpa/howto/use-inheritance.html
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Mar 6, 2009 at 3:00 AM, jsw <marvin.438@xxxxxxxxx> wrote:
>>>>>>>>
>>>>>>>> Environment: JBoss, Jersey, Spring, EclipseLink JPA, PostgreSQL
>>>>>>>>
>>>>>>>> @Entity
>>>>>>>> public abstract class Base {
>>>>>>>> @Id
>>>>>>>> @GeneratedValue(strategy = GenerationType.TABLE)
>>>>>>>> private Long id;
>>>>>>>>
>>>>>>>> @Version
>>>>>>>> private long version;
>>>>>>>>
>>>>>>>> ...
>>>>>>>> }
>>>>>>>>
>>>>>>>> @Entity
>>>>>>>> @Inheritance(strategy=InheritanceType.SINGLE_TABLE)
>>>>>>>> public class Foo extends Base { ... }
>>>>>>>>
>>>>>>>> @Entity
>>>>>>>> @Inheritance(strategy=InheritanceType.SINGLE_TABLE)
>>>>>>>> public class Bar extends Base { ... }
>>>>>>>>
>>>>>>>> Then when I do:
>>>>>>>>
>>>>>>>> Long aId = 76576; // a valid id for an entity of type Bar
>>>>>>>> Foo foo = em.find(Foo.class, aId); // em is EntityManager
>>>>>>>>
>>>>>>>> an exception is thrown (the root cause seems to be
>>>>>>>> ClassCastException)
>>>>>>>> because the EntityManager tries to return an object of type Bar.
>>>>>>>>
>>>>>>>> What am I doing wrong?
>>>>>>>> --
>>>>>>>> View this message in context:
>>>>>>>> http://www.nabble.com/EntityManager.find-returning-instance-of-wrong-type-tp22367490p22367490.html
>>>>>>>> Sent from the EclipseLink - Users mailing list archive at Nabble.com.
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> eclipselink-users mailing list
>>>>>>>> eclipselink-users@xxxxxxxxxxx
>>>>>>>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> eclipselink-users mailing list
>>>>>>> eclipselink-users@xxxxxxxxxxx
>>>>>>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> View this message in context:
>>>>>> http://www.nabble.com/EntityManager.find-returning-instance-of-wrong-type-tp22367490p22371962.html
>>>>>> Sent from the EclipseLink - Users mailing list archive at Nabble.com.
>>>>>>
>>>>>> _______________________________________________
>>>>>> eclipselink-users mailing list
>>>>>> eclipselink-users@xxxxxxxxxxx
>>>>>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>>>>>
>>>>> _______________________________________________
>>>>> eclipselink-users mailing list
>>>>> eclipselink-users@xxxxxxxxxxx
>>>>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>>>>
>>>>>
>>>>
>>>> --
>>>> View this message in context:
>>>> http://www.nabble.com/EntityManager.find-returning-instance-of-wrong-type-tp22367490p22372894.html
>>>> Sent from the EclipseLink - Users mailing list archive at Nabble.com.
>>>>
>>>> _______________________________________________
>>>> eclipselink-users mailing list
>>>> eclipselink-users@xxxxxxxxxxx
>>>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>>>
>>> _______________________________________________
>>> eclipselink-users mailing list
>>> eclipselink-users@xxxxxxxxxxx
>>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>>
>>>
>>
>> --
>> View this message in context: http://www.nabble.com/EntityManager.find-returning-instance-of-wrong-type-tp22367490p22396645.html
>> Sent from the EclipseLink - Users mailing list archive at Nabble.com.
>>
>> _______________________________________________
>> eclipselink-users mailing list
>> eclipselink-users@xxxxxxxxxxx
>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>>
>
