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Re: [eclipselink-users] EntityManager.find returning instance of wrong type
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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.
>>>
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>>>
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>
> --
> 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.
>
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