JDO Inheritance problems

[Valentino Pinna <va...@virgilio.it>]

I have the following classes:

Utente { Integer codice; ...other fields... }
Profilo extends Utente {...other fields...}

I need to map them to two tables (PROFILO and UTENTE) without any redundance
(i.e. Profilo instances obtained from inner joins of PROFILO and UTENTE).

But even with a simple "Profilo.class" query, the following exception is
thrown:

java.lang.NullPointerException
 at
org.apache.ojb.jdori.sql.OjbFieldManager.getValue(OjbFieldManager.java:269)
 at
org.apache.ojb.jdori.sql.OjbFieldManager.fetchStringField(OjbFieldManager.ja
va:202)
 at com.sun.jdori.common.state.StateManagerImpl.replacingStringField(Unknown
Source)
 at app.model.Utente.jdoReplaceField(Utente.java)
 at app.model.Profilo.jdoReplaceField(Profilo.java)
 at app.model.Utente.jdoReplaceFields(Utente.java)
 at com.sun.jdori.common.state.StateManagerImpl.replaceFields(Unknown
Source)
 at
org.apache.ojb.jdori.sql.OjbExtent.provideStateManagers(OjbExtent.java:139)
 at org.apache.ojb.jdori.sql.OjbExtent.<init>(OjbExtent.java:62)
 at
org.apache.ojb.jdori.sql.OjbStoreManager.getExtent(OjbStoreManager.java:212)
 at com.sun.jdori.common.PersistenceManagerImpl.getExtent(Unknown Source)
 at com.sun.jdori.common.query.QueryImpl.checkCandidates(Unknown Source)
 at com.sun.jdori.common.query.QueryImpl.execute(Unknown Source)

I tried this mapping but it doesn't work, please someone helps me!:

<class-descriptor class="app.model.Profilo" table="PROFILO" >
    <field-descriptor
        name="codice"
        column="CODICE"
        jdbc-type="INTEGER"
        primarykey="true"
        autoincrement="true"
        sequence-name="UTENTE"
    >
    </field-descriptor>

    ..other descriptors...

    <reference-descriptor name="super"
     class-ref="app.model.Utente"
     auto-retrieve="true"
     auto-delete="true"
     auto-update="true"
     >
            <foreignkey field-ref="codice" />
    </reference-descriptor>
</class-descriptor>
<class-descriptor
    class="app.model.Utente"
    table="UTENTE"
>
 <extent-class class-ref="app.model.Profilo" />
    <field-descriptor
        name="codice"
        column="CODICE"
        jdbc-type="INTEGER"
        primarykey="true"
        autoincrement="true"
        sequence-name="UTENTE"
    >
    </field-descriptor>

    ...other descriptors...
</class-descriptor>


---------------------------------------------------------------------
To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
For additional commands, e-mail: ojb-user-help@db.apache.org