You would have to do the following around all calls into the framework:
ClassLoader tccl = Thread.currentThread().getContextClassLoader();
try
{
Thread.currentThread().setContextClassLoader(null);
// call into the framework
}
finally
{
Thread.currentThread().setContextClassLoader(tccl);
}
regards,
Karl
On Mon, Jul 7, 2008 at 11:51 PM, Craig Phillips
<[EMAIL PROTECTED]> wrote:
> Hi,
>
> - I can't use Equinox because I discovered a Null Pointer Exception when
> attempting to restart it (in the same "context" loosely speaking --
> embedded); Also, equinox as embedded is not really "instance" based out of
> the box; I logged a bug on the NPE and it's probably fixed by now, but it's
> not officially released as a non-beta and that presents issues for me that I
> plan to avoid;
> - Since I wrote the small layer that creates the Felix instance, I have no
> problem tweaking that code to set the TCL to null (seems easier to do that
> than replicating a context finder);
>
> Dumb question - what is a TCL and how would I go about setting it to null (I
> could also ask the same of the context finder approach but setting something
> to null just sounds way easier) [I have written a class loader / jar loader
> or two or three in my time, so I'm not totally ignorant... just lazy if I can
> get away with it]...
>
> Thanks, Craig
>
> ________________________________
>
> From: [EMAIL PROTECTED] on behalf of Niclas Hedhman
> Sent: Mon 7/7/2008 4:27 PM
> To: [email protected]
> Subject: Re: using pax-logger/log4j in embedded felix (class loader issue)
>
>
>
> On Tue, Jul 8, 2008 at 3:26 AM, Niclas Hedhman <[EMAIL PROTECTED]> wrote:
>> On Tue, Jul 8, 2008 at 1:31 AM, Karl Pauls <[EMAIL PROTECTED]> wrote:
>>> Is it somehow possible that log4j is
>>> doing some classloader magic itself and maybe is using the context
>>> classloader? The context classloader would be the WebAppClassloader I
>>> think ...
>>
>> Good Suggestion. Will investigate that initially.
>
> Ok. Here is the funky bits. Me and Alin Dreghiciu have both been
> looking at different problems today(!) turning out to be the same
> thing.
>
> Craig, if you took the time to try out Equinox, you would probably
> find that it might work in Equinox (the Spring case does), but not in
> Felix and not in Knopflerfish... Why?
>
> Log4J (as Spring in Alin's case) try to use the thread context
> classloader, if one is present, otherwise use the classloader of
> "itself". Hence we are seeing the Webapp classloader being used in
> Log4J's loading of resources, resulting in terrible mismatches.
> So why does it work in Equinox. Equinox sets the thread context
> classloader to something they call ContextFinder, which will look at
> the call stack, and take the first classloader found other than system
> CL, which would be the classloader of Pax Logging Service in your
> case.
>
> So, depending on how you are setting this up, you need to do
> "something", like either replicate the ContextFinder approach, or
> plainly set the TCL to null prior to loading up Felix.
>
> I would be interested to hear if that helps. Also Many Thanks to Karl
> who provided a 'short-cut', as the TCL was not the first thing on my
> mind.
>
>
> Cheers
> Niclas
>
>
>
--
Karl Pauls
[EMAIL PROTECTED]
