Sahoo's Blog

May 2008 Archives

Updated instructions to use OpenJPA in GlassFish

Layout of OpenJPA installation has changed since I last blogged about using OpenJPA in GlassFish. Let's say one installs OpenJPA in a directory called ${OPENJPA_HOME}. Earlier (I am talking about the days when OpenJPA was still in Apache incubator), all the jars would live under ${OPENJPA_HOME}/lib directory. Now, things have changed. The primary artifact, openjpa-${version}.jar, which contains classes built out of OpenJPA codebase lives under ${OPENJPA_HOME}; where as all the other library jars live under ${OPENJPA_HOME}/lib. So, all you need to do is to copy the appropriate jars like this:

 cp ${OPENJPA_HOME}/openjpa*.jar ${OPENJPA_HOME}/lib/*.jar ${GLASSFISH_HOME}/domains/domain1/lib 

For issues, please don't hesitate to contact us at users (at) glassfish.dev.java.net

Bug in Bundle.getResource() in Knopflerfish?

I was running a simple test on multiple OSGi platforms. I am seeing some difference in behavior when I run it on Knopflerfish #2.0.3. Upon investigation, I observed that Bundle.getResource() implementation on Knopflerfish does not use the parent class loader of the bundle even when I set org.osgi.framework.bootdelegation=*.

Here is a simple code that I used to test my theory:

public class Activator implements BundleActivator{


    public void start(BundleContext context) throws Exception {

        Class libClazz = context.getBundle().loadClass("sahoo.Library");

        System.out.println("libClazz = " + libClazz);

        URL libRes = context.getBundle().getResource("sahoo/Library.class");

        System.out.println("libRes = " + libRes);

    }

...

The above code prints non-null value for libClazz, but a null value for libResource. If Bundle.loadClass("sahoo.Library") could load the class, how could Bundle.getResource("sahoo/Library.class") return null? It works as expected in other OSGi implementations.

To ensure that sahoo.Library.class is available in the parent class loader, I wrote a Main class which creates a ClassLoader that has both the knopflerfish framework.jar and my library.jar in search path. I then use that classloader to launch knopflerfish.

Has anyone else faced similar issues? I think this is a serious bug in knopflerfish. I tried to get a confirmation by reporting it in their forum, but no luck. I also tried using the dev forum, but no difference. Is there a better way to ask them questions? I don't know. So I thought I would document what I observed.

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