[news.eclipse.birt] Re: BIRT 2.3: Back in classloader hell!

[Jason Weathersby <jasonweathersby@xxxxxxxxxx>]

Juergen,

Is this an RCP app?

from where is this being called?
appContext.put(EngineConstants.APPCONTEXT_CLASSLOADER_KEY,ReportDataAccess.class.getClassLoader()); 


Can you give some more details?

Jason

Juergen Schwarz wrote:
> Hi,
>
> I have again a classloader problem with our web application using BIRT 
> after upgrading to 2.3:
>
> In the data source plugin we have written, we need to access data from 
> the web application.
>
> We set the classloader as usual like this:
>
> HashMap appContext=birtcfg.getAppContext();
> appContext.put(EngineConstants.APPCONTEXT_CLASSLOADER_KEY,ReportDataAccess.class.getClassLoader()); 
>
> birtcfg.setAppContext(appContext);
>
>
> but we are not able to retrieve the data in the plugin. We need to make 
> a typecast from Object to ReportDataAccess that always fails with a 
> NoClassDefFoundError. The ReportDataAccess class is in the web 
> application's class path.
>
> So I began to research what happens in the plugin. There seem to be 
> several classloaders involved:
>
> - The first one seems to be used for instantiating classes or type 
> casting within the plugin:
>
> org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader@14b1fda
> parent: org.eclipse.osgi.baseadaptor.BaseAdaptor$ParentClassLoader@34151f
>
>
> - The second one is the thread context class loader (which seems to have 
> been set using the APPCONTEXT_CLASSLOADER_KEY) which could find my class:
>
> WebappClassLoader
> parent: org.apache.catalina.loader.StandardClassLoader@3dc0bb
>
>
> So, why is the thread context class loader not used for the type cast, 
> but the "wrong" osgi classloader?
>
> I'm really stuck now, I've no idea what to try next...