Thanks Peter! Assuming this works (and Paul's confirmed), this is perfect. I'll even move some of the sample mailets/matchers into the classes directory so ant moves them and mailet developers will more readily see some sample code. Thanks again.
Serge Knystautas Loki Technologies - Unstoppable Websites http://www.lokitech.com/ ----- Original Message ----- From: "Peter Donald" <[EMAIL PROTECTED]> To: "Avalon Developers List" <avalon-dev@jakarta.apache.org> Sent: Tuesday, November 06, 2001 12:05 AM Subject: Re: Classloader thoughts? > On Thu, 1 Nov 2001 16:00, Serge Knystautas wrote: > > Peter, > > > > After trying (and failing) to get mailets loading from anything besides > > james.bar, I read your message from Sept 30. First, let me explain what I > > want to do (in james), what I tried, and what happened: > > kool. > > > Ideally james.sar could create an app/james/classes directory, that I would > > probably populate with a sample mailet if necessary, and any class in this > > classes directory would get loaded by the > > org.apache.avalon.phoenix.components.classloader.PolicyClassLoader that > > loads the bars in apps/james/blocks and jars in apps/james/lib. Perhaps > > this could get loaded by a classloader that has this PolicyClassLoader as a > > parent so that the apps/james/classes classloader could be recycled so I > > could reload mailet classes without needing to reload all the James > > classes. > > In theory all the jars in blocks/ and lib/ directory should be loaded via the > same ClassLoader (However we experimented with a few things re ClassLoader a > bit back so that may have caused issues). So in theory you should be able to > do something like the following. > > BlockContext context = ...; > File homeDir = context.getHomeDirectory(); > File classesDir = new File( homeDir, "classes" ); > URL[] urls = new URL[] { classesDir.toURL() }; > > ClassLoader parent = James.class.getClassLoader(); > > URLClassLoader classloader = URLClassLoader.newInstance( urls, parent ); > > then in theory you should be able to load mailets/matchers out of this > classloader. You should also be able to throw it away later and reload it all > providing that all matchers/mailets are in classes/ directory. > > > If that's too ambitious for now, I would like to be able to add a jar to > > the app/james/lib directory and have it load. Unfortunately it seems the > > sar remembers what jars it put in apps/james/lib, and if I put another jar > > in there, avalon ignores it. > > As it was then the .sar is only extracted the first time it is spotted. So if > you want ti to be extracted again it is necessary to delete the directory. > Though I have been thinking about a few things related to this of late. Stay > tuned ;) > > > My last recourse was to put my jar in the core lib directory, which gets > > loaded by sun.misc.Launcher$ExtClassLoader, because the run scripts now set > > that lib folder as the ext folder. Unfortunately mailets in there can't > > access the mailet.jar, mail.jar, or activation.jar classes, so the server > > just hangs (kind of weird... never throws any exception... I would if this > > is a bug in the ExtClassLoader). > > eek - no idea ;) > > > Mapping out a series of ClassLoaders might be useful, but as you mentioned, > > I'm not sure how that would look in server.xml. Do you need the extra > > method to BlockContext to get the classloader since on object in that block > > would return the same thing by calling getClass().getClassLoader(), or > > would it return something different? > > well it could return something different - depending on which ClassLoader you > asked for. For instance in the other thread where I was discussin similar > things with Paul you may want to > > ClassLoader classLoader = getClassLoader( "client-api" ); > > which would get the class loader that only contained mailet.jar in it. > > -- > Cheers, > > Pete -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
