OSGi / Equinox Classloader Uses Unexpected Version of Bundle

Question

I have an OSGI application with Bundles that requires 2 versions of IBM MQSeries: 6.0.2 and 7.0.1. We have installed the following IBM MQ Bundles packages (basic mention only)

• com.ibm.mq.osgi.client_6.0.2.5.jar
• com.ibm.msg.client.osgi.wmq_7.0.1.5.jar

We defined our 2 Bundles per Requirement-Bundle as follows (yes, I know, we should use import-package ;-)) A Require-Bundle: com.ibm.msg.client.osgi.wmq;bundle-version="7.0.1"

B Package Require-Bundle: com.ibm.mq.osgi.client;bundle-version="[6.0.2,7.0.0)"

We additionally define org.osgi.framework.bootdelegation=javax.* . No buddy class loading, no dynamic class loading.

Now that Bundle A is loading com.ibm.mq.jms.MQQueueConnectionFactory using

 final MQQueueConnectionFactory connectionFactory = new MQQueueConnectionFactory(); 

I would expect Equinox to load the class from Bundle com.ibm.msg.client.osgi.wmq_7.0.1.5 . This is not the case!?!?? MQQueueConnectionFactory is loaded from Bundle com.ibm.mq.osgi.client_6.0.2.5 !!

As a result, Bundle A uses MQ 6.0.2.5.

Configuring some Equinox debugging options, I see the following:

 Bundle id 56 == com.ibm.mq.osgi.client_6.0.2.5 Bundle id 53 == com.ibm.msg.client.osgi.jms.prereq_7.0.1.5 [...] BundleLoader[A_1.1.3].loadBundleClass(com.ibm.mq.jms.MQQueueConnectionFactory) BundleLoader[com.ibm.mq.osgi.client_6.0.2.5].findLocalClass(com.ibm.mq.jms.MQQueueConnectionFactory) BundleClassLoader[PATH/org.eclipse.osgi/bundles/56/1/.cp/com.ibm.mq.jar].findClassImpl(com.ibm.mq.jms.MQQueueConnectionFactory) BundleClassLoader[PATH/org.eclipse.osgi/bundles/56/1/.cp/com.ibm.mqjms.jar].findClassImpl(com.ibm.mq.jms.MQQueueConnectionFactory) about to read 11659 bytes from com/ibm/mq/jms/MQQueueConnectionFactory.class read 11659 bytes from PATH/org.eclipse.osgi/bundles/56/1/.cp/com.ibm.mqjms.jar/com/ibm/mq/jms/MQQueueConnectionFactory.class defining class com.ibm.mq.jms.MQQueueConnectionFactory [...] 

The "funny" part is that the javax.jms classes. * loaded from com.ibm.msg.client.osgi.jms.prereq_7.0.1.5

 BundleClassLoader[com.ibm.mq.osgi.client_6.0.2.5].loadClass(javax.jms.QueueConnectionFactory) BundleLoader[com.ibm.mq.osgi.client_6.0.2.5].loadBundleClass(javax.jms.QueueConnectionFactory) BundleLoader[com.ibm.msg.client.osgi.jms.prereq_7.0.1.5].findLocalClass(javax.jms.QueueConnectionFactory) BundleClassLoader[PATH/org.eclipse.osgi/bundles/53/1/.cp/jms.jar].findClassImpl(javax.jms.QueueConnectionFactory) about to read 371 bytes from javax/jms/QueueConnectionFactory.class read 371 bytes from /opt/fxportal/FXMB/application/configuration/org.eclipse.osgi/bundles/53/1/.cp/jms.jar/javax/jms/QueueConnectionFactory.class defining class javax.jms.QueueConnectionFactory BundleLoader[com.ibm.msg.client.osgi.jms.prereq_7.0.1.5] found local class javax.jms.QueueConnectionFactory 

IMHO, this is due to the installation of org.osgi.framework.bootdelegation and the fact that the preliminary version of JMS 7.0.1.5 occurs before version 6.0.2.5.

Can someone explain the behavior of the Bundle class loader? Why does Equinox lay A in this way? And how can I achieve the expected behavior?

Package B works as expected ...

Answer 1

Not if this is the correct answer, but try using this format when defining a dependency in BUndle A version = "[7.0.1.7.0.1]", which denotes a strict version range. Also the worst case, if you still have problems, you can load the class directly from the Bundle by executing Platform.getBundle ("com.ibm.msg.client.osgi.wmq"). LoadClass ("com.myclass")?

Answer 2

I came across a similar situation when I use OSGi-related coding in the IDE. This posting made by your IDE is incorrect. It draws a class from com.ibm.mq.osgi.client_6.0.2.5 , while you expect it to include the same class com.ibm.msg.client.osgi.wmq_7.0.1.5 . The same problem occurs when you spoke in the second issue. You can verify this by finding the class com.ibm.mq.jms.MQQueueConnectionFactory , where the IDE uses it. (You can use Ctrl + Mouse to see which version is connected).