Hi using this development setup:

I have injected the InstanceContainer and set transaction support via jboss-portlet.xml:

 <service>
 <service-name>InstanceContainer</service-name>
 <service-class>org.jboss.portal.core.model.instance.InstanceContainer</service-class>
 <service-ref>:container=Instance</service-ref>
 </service>

and

<trans-attribute>Required</trans-attribute>

Reading from the portlet instnaces does work, writing to the portlet preferences creates a nullpointer, using this example code:

//Get the instance container
InstanceContainer instanceContainer = (InstanceContainer) this.getPortletRequest().getPortletSession().getPortletContext().getAttribute("InstanceContainer");
InstanceDefinition id = instanceContainer.getDefinition("startPortletInstance");

// This does work!
PropertyMap pmap = id.getProperties();
String uuid = ((StringValue) pmap.get("uuid")).toString();

List tmp = new ArrayList();
if (pmap.containsKey("uuid")) {
 PropertyChange change = PropertyChange.newUpdate("uuid", new StringValue(documentId));
 tmp.add(change);
}
PropertyChange[] changes = (PropertyChange[]) tmp.toArray(new PropertyChange[tmp.size()]);
//This doesn't work
id.setProperties(changes);

I have debugged the setProperties() method for my portlet und the admin portlet and found the problematic section:

org.jboss.portal.core.impl.portlet.state.PersistentPortletStatePersistenceManager

The following code line leads to the nullpointer:

context.entries.clear();

The problem seems to be, that the loaded (hibernate?) PersistentPortletState object is not set up correctly, most properties are empty. I have compared this to the admin-core portlet - there is the object loaded correctly.

Some questions:

1. Am i gettin the InstanceCotainer correctly:

InstanceContainer instanceContainer = (InstanceContainer) this.getPortletRequest().getPortletSession().getPortletContext().getAttribute("InstanceContainer");