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Re: dealing with ClassLoaders...

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Josip Almasi <joe@vrspace.org> wrote:
> On 08/04/2014 05:12 PM, Andreas Leitgeb wrote:
>> But it seems like it doesn't really make it easy to use it
>> that way.
> Noone said it's easy;)

;)

> Don't worry, it won't be silent:>
> Mess up anything, and you get strange ClassCastExceptions.

Well, if due to a bug all references to a certain class
came from System classloader, then there would not be
any ClassCastExceptions, but no isolation, either.

Anyway, I got the classloader working well enough for my needs
and I posted the final snippet somewhere in this thread. I used
URLs, because that's what getSystemResource() gives me. They
need not be remote (and in my case aren't remote).

>>> Also, make sure your loaders don't load the same packages.

I think I got confused about this advice, in that I thought
it was meant to point out a technical requirement, when it
really was just a hint (and a good one, btw).

> I used something like
> JarEntry entry = (JarEntry) jarFile.getEntry( name+".class" );
> InputStream stream = jarFile.getInputStream(entry);
> int size = (int) entry.getSize();
> byte[] code = new byte[size];
> I also stated with URL but gave it up, because of unknown length.

I didn't really want to hardcode any particular way to access the 
class-files.  They may be in Jar file after deploy, but e.g. in
eclipse they're just plain files.
Even at the cost of having to grow the ByteArrayOutputStream.

Thanks for caring

PS: Right after I got a "safe-point" with a working custom classloader,
I started un-static'izing the relevant classes. I see myself at 80% 
done, but the remaining 80% will still be rather tough... ;-)

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Thread

dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-07-31 19:40 +0000
  Re: dealing with ClassLoaders... Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-31 20:44 +0000
    Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-01 14:22 +0000
      Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-01 21:10 +0000
        Re: dealing with ClassLoaders... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-01 17:32 -0400
          Re: dealing with ClassLoaders... Joerg Meier <joergmmeier@arcor.de> - 2014-08-02 01:21 +0200
          Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-02 00:00 +0000
        Re: dealing with ClassLoaders... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-01 21:45 +0000
          Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-01 23:14 +0000
            Re: dealing with ClassLoaders... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-02 00:35 +0000
              Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-05 15:38 +0000
  Re: dealing with ClassLoaders... Silvio <silvio@internet.com> - 2014-08-01 13:31 +0200
    Re: dealing with ClassLoaders... Silvio <silvio@internet.com> - 2014-08-01 13:37 +0200
      Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-01 16:06 +0000
  Re: dealing with ClassLoaders... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-08-01 13:19 +0100
    Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-01 15:51 +0000
  Re: dealing with ClassLoaders... Josip Almasi <joe@vrspace.org> - 2014-08-01 15:55 +0200
    Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-04 15:12 +0000
      Re: dealing with ClassLoaders... Mike Amling <mamling@chaff.us> - 2014-08-04 19:53 -0500
        Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-05 15:16 +0000
      Re: dealing with ClassLoaders... Josip Almasi <joe@vrspace.org> - 2014-08-08 11:53 +0200
        Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-08 18:46 +0000
          Re: dealing with ClassLoaders... Josip Almasi <joe@vrspace.org> - 2014-08-10 13:22 +0200
            Re: dealing with ClassLoaders... Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2014-08-12 17:16 +0000

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