+0 ie go for it!
Paul Hammant wrote:
>
> I've talked this over with the big Guns of Avalon, some month back and tried a
>couple of suggested
> solutions (including thread context based ones), but nothing worked for the unique
>situation I had
> at the time.
>
> The problem re-interated is that Jesktop (block) mounts many of it's own
>classloaders for
> hot-installable and hot-upgradable apps. Some of them want to persist data, and the
>persistence
> store is the obvious place to do it. The trouble is that a ClassNotFoundException
>was always
> thrown because the Store couldn't work out which of the ten or so different
>classloaders had the
> definition of the class. Thread.setContextClassLoader(..) didn't work either.
>
> What was tested at the time, but objected to because of inelegance was a way of
>passing in the
> classloader for use _during_ the internal store code to deserialize objects. I
>tested it and it
> worked, but under pressure from said guns, tried other things. Then I moved
>countries, jobs, went
> on a diet and saw thru a heavy winter ;-) Now, older and wiser, I'd like to
>re-propose a tuned
> additonal get() method for store:
>
> 1) ObjectRepository (interface ) -> new method ->
>
> Object get( String key , ClassLoader classLoader );
>
> 2) File_Persistent_Object_Repository (class) new method :
>
> public synchronized Object get( final String key , final ClassLoader classLoader
>)
> {
> ......
> }
>
> 3) File_Persistent_Object_Repository (class) new inner class :
>
> /**
> * A special ObjectInputStream to handle highly transient classes hosted by
>Avalon components
> * that are juggling many classloaders.
> */
> private class FileStoreObjectInputStream extends ObjectInputStream
> {
> private ClassLoader classLoader;
> private FileStoreObjectInputStream(ClassLoader classLoader, InputStream in)
> throws IOException, StreamCorruptedException
> {
> super(in);
> this.classLoader = classLoader;
> }
> protected Class resolveClass(ObjectStreamClass v)
> throws IOException, ClassNotFoundException
> {
> Class cl = Class.forName(v.getName(), false, classLoader);
> if (cl !=null)
> {
> return cl; // the classloader knows of the class
> }
> else
> {
> // classloader knows not of class, let the super classloader do it.
> return super.resolveClass(v);
> }
> }
> }
>
> What's thought of this?
>
> =====
> Regards - Paul H
> ====
> CVS -1, Perforce +1
>
> __________________________________________________
> Do You Yahoo!?
> Get email at your own domain with Yahoo! Mail.
> http://personal.mail.yahoo.com/
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
