Changing existing objects from Entity to Embedded

Hi,

I realised that I have a mistake (from application logic point of view) in one of my JDO metadata files:

<jdo>
<package name="my.example.package">
 
  <class name="InnerSettings">
   <field name="attributes" embedded="true">
    <map embedded-key="true" embedded-value="true" />
   </field>
  </class>
 
  <class name="BasicSettings">
   <field name="userRoles" embedded="true"/>
   <field name="innerSettings" embedded="true">
    <map embedded-key="true" embedded-value="true" />
   </field>
  </class>
 
  <class name="StoreSettings" persistence-capable-superclass="BasicSettings"/>
  <class name="AnalyzeSettings" persistence-capable-superclass="BasicSettings"/>
</package>
</jdo>

All of these 3 classes should be embedded-only as they are stored only in a HashMap of another Entity.

So as first try I changed only the metadata to this:

<jdo>
<package name="my.example.package">
 
  <class name="InnerSettings" embedded-only="true">
   <field name="attributes" embedded="true">
    <map embedded-key="true" embedded-value="true" />
   </field>
  </class>
 
  <class name="BasicSettings" embedded-only="true">
   <field name="userRoles" embedded="true"/>
   <field name="innerSettings" embedded="true">
    <map embedded-key="true" embedded-value="true" />
   </field>
  </class>
 
  <class name="StoreSettings" persistence-capable-superclass="BasicSettings"/>
  <class name="AnalyzeSettings" persistence-capable-superclass="BasicSettings"/>
</package>
</jdo>

The application seemed to work normally with existing values and also the new values got stored in DB.

However since this change I can not open the DB file in Explorer.

I get this exception:

java.lang.ClassCastException: com.objectdb.jpa.type.EmbeddableTypeImpl cannot be cast to com.objectdb.jpa.type.IdentifiableTypeImpl
at com.objectdb.jpa.type.IdentifiableTypeImpl.<init>(IdentifiableTypeImpl.java:63)
at com.objectdb.jpa.type.EntityTypeImpl.<init>(EntityTypeImpl.java:42)
at com.objectdb.jpa.MetamodelImpl.a(MetamodelImpl.java:323)
at com.objectdb.jpa.MetamodelImpl.b(MetamodelImpl.java:287)
at com.objectdb.jpa.MetamodelImpl.c(MetamodelImpl.java:232)
at com.objectdb.jpa.MetamodelImpl.getManagedTypes(MetamodelImpl.java:97)
at com.objectdb.o.EHL.k(EHL.java:58)
at com.objectdb.o.MetamodelItem.<init>(MetamodelItem.java:39)
at com.objectdb.o.SchemaPanel.g(SchemaPanel.java:126)
at com.objectdb.o.MainFrame.f(MainFrame.java:235)
at com.objectdb.o.MainFrame.f(MainFrame.java:233)
at com.objectdb.o.MainFrame.f(MainFrame.java:233)
at com.objectdb.o.MainFrame.f(MainFrame.java:233)
at com.objectdb.o.MainFrame.e(MainFrame.java:218)
at com.objectdb.o.EXA.k(EXA.java:196)
at com.objectdb.o.EXA.j(EXA.java:188)
at com.objectdb.o.CNC.s(CNC.java:120)
at com.objectdb.o.EXA.<init>(EXA.java:87)
at com.objectdb.Explorer$1.run(Explorer.java:57)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

I thought that simply changing JDO metadata is not sufficient. Should it be sufficient btw ?

So I left these classes NOT embedded in JDO, introduced copies of these classes in another package which were defined as embedded-only, made a migration utility which read the original objects, converted them to the new classes and stored them instead of the old ones. The old ones I deleted.

And again the app was working fine, but on opening the DB file in Explorer I got again the above exception.

I would appreciate some guidance in this matter.

Is the change of not-embedded to embedded supported by ObjectDB for existing objects? If it is, do I have to write the "embedded-only" clausule also to the child classes or is it sufficient to write it on their predecessor ?

Is this only a bug in Explorer? Or do I have to change something in my code ?

Thx.

I forgot to mention that I am using ObjectDB 2.6.9.b08 on linux, but I tried the migration and the explorer also from version 2.7.2_09 and it made no difference.

Looks like this was caused by incorrect JDO metadata.
Once I added the 
embedded-only="true"
also to the subclasses, the migration started to work and Explorer opens the file without errors.

This is correct. In ObjectDB 2.0 classes can be either persistence capable (entity classes) or embeddable. To use embedded objects you must declare classes as embeddable (rather than the reference fields as in ObjectDB 1.0), either by annotation (@Embeddable) or by external XML metadata (<class name="MyClass" embedded-only="true"> in package.jdo).