The proxies comment is irrelevant to the solution I noted.
You need to change:
<reference-descriptor name="group"
class-ref="test.ojb.datamodel.Group" proxy="true" >
To:
<reference-descriptor name="group"
class-ref="test.ojb.datamodel.GroupImpl" proxy="true" >
As far as my comment regarding proxies, in general we get better
performance by NOT proxying reference descriptors. We do however
increase performance by proxying collection descriptors. I would
suggest running tests both ways in your environment.
Wally
-----Original Message-----
From: Maksimenko Alexander [mailto:[EMAIL PROTECTED]
Sent: Thursday, March 03, 2005 11:19 AM
To: OJB Users List
Subject: Re: ojb and interface driven design
thanks for idea but its unfortunately doesn't fit to me :( because i'm
need using proxies for perfomance reasons
of cause user a 1-m to group - but i created this example to simplify
understanding by problem - in real project my classes are big enough and
ojb descriptor is huge ;)
Gelhar, Wallace Joseph wrote:
>I've ran into this before. I think the solution I found was to map the
>reference / collection descriptor classes to the implementing
>descriptor as follows:
>
><class-descriptor
> class="test.ojb.datamodel.User">
> <extent-class class-ref="test.ojb.datamodel.impl.UserImpl"/>
></class-descriptor><class-descriptor
>class="test.ojb.datamodel.impl.UserImpl"
> table="USER"
> factory-class="test.ojb.datamodel.impl.FactoryImpl"
> factory-method="createUser">
> <field-descriptor
>...
> <reference-descriptor
> name="group"
> class-ref="test.ojb.datamodel.GroupImpl"
> proxy="true"
> >
> <foreignkey field-ref="groupId"/>
> </reference-descriptor>
></class-descriptor>
>
><class-descriptor
> class="test.ojb.datamodel.Group">
> <extent-class class-ref="test.ojb.datamodel.impl.GroupImpl"/>
></class-descriptor>
><class-descriptor
> class="test.ojb.datamodel.impl.GroupImpl"
> table="GROUP1"
> factory-class="test.ojb.datamodel.impl.FactoryImpl"
> factory-method="createGroup">
> <field-descriptor
>...
> <reference-descriptor
> name="manager"
> class-ref="test.ojb.datamodel.UserImpl"
> proxy="true"
> >
> <foreignkey field-ref="managerId"/>
> </reference-descriptor>
></class-descriptor>
>
>Also just note that it usually doesn't pay to proxy reference
>descriptors since these can often be retrieved effeciently with one
>query to the database. Although it might make sense if you have a lot
>of 1-1 relations that are not routinely used. I usually proxy
>collection descriptors though.
>
>The query for the interface class is perfectly fine.
>
>BTW is user really a 1-1 with group? I would normally make this a 1-m
>relation.
>
>Hope this helps.
>
>Wally
>
>-----Original Message-----
>From: Maksimenko Alexander [mailto:[EMAIL PROTECTED]
>Sent: Thursday, March 03, 2005 10:25 AM
>To: OJB Users List
>Subject: ojb and interface driven design
>
>hi!
>
>it's wondering but I found out that its difficult to use interface
>driven design with ojb ;( lets consider a simple 2-table example:
>
>interface User{Integer getId(),Group getGroup()}, class UserImpl
>implements User{private Integer id; private Group group; access
>methods}
>
>interface Group{Integer getId(),User getManager()}, class GroupImpl
>implements Group{private Integer id;privarte User manager; access
>methods}
>
>What repository descriptor should be to get correct results with the
>following query:
>
>QueryByCriteria query = QueryFactory.newQuery(User.class,new
>Criteria());
>query.getCriteria().addEqualTo("group.manager.id",new Integer(4));
>Collection users = broker.getCollectionByQuery(query);
>
>Standard approach in mapping is not working ;(
>
><class-descriptor
> class="test.ojb.datamodel.User">
> <extent-class class-ref="test.ojb.datamodel.impl.UserImpl"/>
></class-descriptor>
><class-descriptor
> class="test.ojb.datamodel.impl.UserImpl"
> table="USER"
> factory-class="test.ojb.datamodel.impl.FactoryImpl"
> factory-method="createUser">
> <field-descriptor
> name="id"
> column="ID"
> jdbc-type="INTEGER"
> primarykey="true"
> nullable="false"
> autoincrement="true"
> access="readonly"/>
> <field-descriptor
> name="groupId"
> column="GROUP_ID"
> jdbc-type="INTEGER"
> access="anonymous"
> />
> <reference-descriptor
> name="group"
> class-ref="test.ojb.datamodel.Group"
> proxy="true"
> >
> <foreignkey field-ref="groupId"/>
> </reference-descriptor>
></class-descriptor>
>
><class-descriptor
> class="test.ojb.datamodel.Group">
> <extent-class class-ref="test.ojb.datamodel.impl.GroupImpl"/>
></class-descriptor>
><class-descriptor
> class="test.ojb.datamodel.impl.GroupImpl"
> table="GROUP1"
> factory-class="test.ojb.datamodel.impl.FactoryImpl"
> factory-method="createGroup">
> <field-descriptor
> name="id"
> column="ID"
> jdbc-type="INTEGER"
> primarykey="true"
> nullable="false"
> autoincrement="true"
> access="readonly"/>
> <field-descriptor
> name="managerId"
> column="MANAGER_ID"
> jdbc-type="INTEGER"
> access="anonymous"
> />
> <reference-descriptor
> name="manager"
> class-ref="test.ojb.datamodel.User"
> proxy="true"
> >
> <foreignkey field-ref="managerId"/>
> </reference-descriptor>
></class-descriptor>
>
>
>
>
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