Guice 3.0 is imminent.  The release notes claim that it has better support
for multiple classloaders and OSGi.

On Tue, Jan 11, 2011 at 11:59 AM, Ryan J Baxter <[email protected]> wrote:

> Today I ran into a few problems with the class loader Shindig is using in
> some of it's classes, specifically within the ResourceLoader and
> GuiceServletContextListener classes.  For my project I am embedding
> Shindig inside an Eclipse based application.  To do this we have decided
> to modularize Shindig a bit, and separate out the libraries (jars in the
> lib folder) Shindig uses into one plugin, and the actual web app into a
> different plugin.  Once I did this however Shindig could no longer find
> any of my guice modules, customized shindig.properties file, or customized
> container.js file living in the web app plugin.  In the end I figured out
> this was happening because of the class loader some of the Shindig classes
> use.  From what I found, it looks like we are either using the current
> classes class loader or doing Class.forName(className) to load classes and
> resources.  This is fine when a web app is running on Tomcat or Jetty but
> in OSGi this can possibly break.  In OSGi, the class loader will use the
> current bundle's context.  So if you have a class foo within a jar in
> bundle A using the methods in Shindig today to load a class bar from
> bundle B, the class foo will use bundle A's class loader and cannot find
> the class bar in bundle B.  The easiest way to fix this would be to try to
> use the class loader returned from
> Thread.currentThread().getContextClassLoader(), when the current codes
> class loader fails to load the class or resource requested.  So far I have
> found problems in ResourceLoader.openResource and
> GuiceServletContextListener.contextInitialized.  The problem in
> GuiceServletContextListener I can work around by extending this class and
> overriding contextInitialized, however there is no way for me to work
> around the problem in ResourceLoader, so I figured I would make the change
> in GuiceServletContextListener as well.  Does anyone have any objection to
> me making these changes, and does anyone know of other spots in Shindig
> where I may run into similar problems?
>
> -Ryan
>
> Email: [email protected]
> Phone: 978-899-3041
> developerWorks Profile
>
>


-- 
Paul Lindner -- [email protected] -- linkedin.com/in/plindner

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