db4o Developer Community

Eclipse uses many class loaders.  In your configuration file try this: final Configuration config = Db4o.configure(); MyPersistantClass myObject = new MyPersistantClass() ;ClassLoader cl = myObject.getClass().getClassLoader();config.reflectWith(new JdkReflector(cl));

I'm not sure which OSGi framework you are using. If you are running on Eclipse Equinox then you can make use of an Eclipse specific extension called ''buddy classloading''. However, this limits your ability to run your bundles on other OSGi frameworks. Basically, you would create a DB4O bundle and add the following to it's bundle ...

Hi, I have a bundle which which exposes an instance of ObjectContainer, let's call this the ''arum.db'' bundle.  This bundle uses a ServiceTracker to track db4o_osgi.  During the ''addingService'' method of my tracker, I get the Db4oService service and call service.openFile().  I then register a service which my other bundles can ...

tneward:jre/lib/ext isn't *just* for core JDK classes--far from it. Any extension library (and db4o marks a good candidate here) can be put there, such as scripting languages and the like.A optional package is an implementation of an open, standard API (examples of optional packages from Sun are JavaServlet, Java3D, JavaManagement). Most ...

Hi, I've seen that this forum has a few questions like mine, but they are for java, not vb.net and I can not see how I can fix this myself. The problem is that I have an external ''plugin'' class which returns an 'object' My main program then creates a new ConfigObject class and sets one of the properties to this 'object' my plugin ...

Carl Rosenberger:If we try to be smarter about ClassLoaders, by finding the right one for each class, we would also make things easier for app server use. Can we solve this in a generic way? In principle we should have the required level of encapsulation in place already with the reflector layer. Perhaps it could already be sufficient to ...

Patrick Roemer: ...and it's a general db4o/Java issue, nothing particularly OSGi specific - you can shoot yourself in the foot the same way when deploying db4o as a shared library within an app server, for example. That's a very good point: If we try to be smarter about ClassLoaders, by finding the right one for each class, we would also ...

First of all: I don't see that (at the moment) the ''db4o as a service plugin'' scenario is targeted at all - the mail you forwarded just requests that we provide OSGi relevant meta data in the jar and seems to target db4o as a library within the confines of a single plugin. Have I missed something? Carl Rosenberger: > Different classloaders ...

Natalia W.:javax.xml.ws.soap.SOAPFaultException: com.db4o.reflect.generic.GenericObject[...](G) my.package.Seans db4o doesn't seem to able to find the class definitions for your persisted objects, thus the generic reflector kicks in. You will have to configure db4o to use the appropriate classloader. I don't know Sun Application Server, so I ...

Marek Istvanek:What is the state of support for dynamically loaded types not known at compile time? Currently there is no explicit support for that. I suppose this is a .NET question?  On the Java side it usually helps to configure db4o to use the appropriate class loader. (This approach requires some improvisation and dirty hacks if ...