During 'Bundelization' of the JacORB CORBA library I encountered a problem already seen when using log4j as a:
Libraries that load classes by name often use the thread context classoader for loading. I guess, this due to the fact that it's often necessary to pass a special classloader into the library. Indeed, within felix this is needed in some circumstances. E.g., to get an ORB instance one calls org.omg.CORBA.ORB.init(). This method (part of the standard java runtime) reads the actual name of the class that implements an ORB-factory from a system property , and then uses the thread context classloader to instantiate the factory. When ORB.init() is called from a bundle-activator, and the system properties state that JacORB should be used as ORB-Factory, this fails, even if the bundle under activation has a correct Import-Package statement for the jacorb bundle. The problem is, that the thread-context-classloader in effect when bundles are activated is NOT the classloader of the module, but the standard Application Class Loader. I could fix the problem with this code: Thread.currentThread().setContextClassLoader( org.jacorb.orb.ORB.class.getClassLoader()); This sets the context class loader to the class loader of the bundle being activated, and ORB.init() succeeds now. A very similar problem arises when using the log4j bundle with custom loglevel classes. These classes are instantiated by the thread context classloader during log4j initialization, what fails if the thread context class loader has not been set to the bundle classloader. Finally, here comes my suggestion: Wouldn't it make sense to always set the thread context classloader to the bundle-classloader within the framework before calling BundleActivator.start() and BundleActivator.stop()? If this does not violate the OSGi standard, I'd suggest to add this (perhaps configurable) to the felix framework code. Kind regards, Martin ************************************************ The information contained in, or attached to, this e-mail, may contain confidential information and is intended solely for the use of the individual or entity to whom they are addressed and may be subject to legal privilege. If you have received this e-mail in error you should notify the sender immediately by reply e-mail, delete the message from your system and notify your system manager. Please do not copy it for any purpose, or disclose its contents to any other person. The views or opinions presented in this e-mail are solely those of the author and do not necessarily represent those of the company. The recipient should check this e-mail and any attachments for the presence of viruses. The company accepts no liability for any damage caused, directly or indirectly, by any virus transmitted in this email. ************************************************ --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@felix.apache.org For additional commands, e-mail: users-h...@felix.apache.org
