Apache JDO Project - Re: Support java.lang.Object as FCO

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Author Re: Support java.lang.Object as FCO
Michelle Caisse

2005-08-17, 5:45 pm

Hi Andy,

It seems that jpox maps Object as serialized by default. Where there is
no serialized or embedded attribute on the field, we map to a FK column,
e.g. OBJECT102 BIGINT REFERENCES SIMPLE_CLASS, giving a jpox error:

An attempt was made to put a data value of type 'byte[]' into a data
value of type 'BIGINT'.

SimpleInterface, which we map identically to Object, works fine.

-- Michelle

Andy Jefferson wrote:

>
>
>
>
>OK, JPOX now supports java.lang.Object as FCO. It's not currently using the
>proposed <field> attribute to notate which classes will actually be stored in
>that field, instead using
><field name="myObjectField>
> <extension vendor-name="jpox" key="implementation-classes"
>value="comma-separated-list-of-PC-classnames-that-can-be-stored-here"/>
></field>
>
>When we have an agreed JDO2 attribute, I'll swap it over to that.
>
>The TCK now gives exceptions of the following style, due to absence of
>possible classes against each Object (or Collection of Object) field :-
>javax.jdo.JDOUserException: Field
>"org.apache.jdo.tck.pc.fieldtypes.ArrayListCollections.ArrayListOfObject2" is
>declared as a reference type (interface/Object) but no implementation classes
>of "java.lang.Object" have been found!
>
>HTH
>
>



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