[jboss-dev-forums] [Design of AOP on JBoss (Aspects/JBoss)] - Re: AOP ClassLoader/Scoping for the VFSClassLoader

[adrian@jboss.org]

Looks like there is lot more work to this.

The original refactoring just dealt with the aop project (AspectManager).
There's also a lot of deep integration in the asintegration project (AspectManagerService).

I've manged to come up with an alternate integration interface that encapsulates all this:


  | package org.jboss.aop.deployment;
  | 
  | import java.io.File;
  | 
  | import javassist.scopedpool.ScopedClassPoolFactory;
  | 
  | import org.jboss.aop.ClassLoaderValidation;
  | import org.jboss.aop.classpool.AOPClassLoaderScopingPolicy;
  | 
  | /**
  |  * AOPIntegration.<p>
  |  * 
  |  * This class is intended to identify all the integration
  |  * points AOP is making with the JBoss appserver.
  |  * 
  |  * @author <a href="adrian at jboss.com">Adrian Brock</a>
  |  * @version $Revision: 1.1 $
  |  */
  | public interface JBossIntegration extends ClassLoaderValidation, ScopedClassPoolFactory
  | {
  |    /**
  |     * Create the AOPClassLoaderScopingPolicy
  |     * 
  |     * @return the policy
  |     */
  |    AOPClassLoaderScopingPolicy createAOPClassLoaderScopingPolicy();
  | 
  |    /**
  |     * Create a scoped classpool factory
  |     *
  |     * TODO JBAOP-??? need to review whether ScopedClassPool should also be replaced with
  |     *      some other policy, e.g. javassist ClassPath notion is closer to new classloader?
  |     * @param tmpDir the temporary directory for classes
  |     * @return the factory
  |     * @throws Exception for any error
  |     */
  |    ScopedClassPoolFactory createScopedClassPoolFactory(File tmpDir) throws Exception;
  |    
  |    /**
  |     * Attach the depreacted translator
  |     */
  |    void attachDeprecatedTranslator();
  | 
  |    /**
  |     * Detach the deprecated translator
  |     */
  |    void detachDeprecatedTranslator();
  | }
  | 

And an implementation for the old stuff

  | package org.jboss.aop.deployment;
  | 
  | import java.io.File;
  | 
  | import javax.management.Attribute;
  | import javax.management.AttributeNotFoundException;
  | import javax.management.InstanceNotFoundException;
  | import javax.management.InvalidAttributeValueException;
  | import javax.management.MBeanException;
  | import javax.management.MBeanServer;
  | import javax.management.ReflectionException;
  | 
  | import javassist.ClassPool;
  | import javassist.scopedpool.ScopedClassPool;
  | import javassist.scopedpool.ScopedClassPoolFactory;
  | import javassist.scopedpool.ScopedClassPoolRepository;
  | 
  | import org.jboss.aop.AspectManager;
  | import org.jboss.aop.classpool.AOPClassLoaderScopingPolicy;
  | import org.jboss.aop.classpool.AOPScopedClassLoaderHelper;
  | import org.jboss.aop.classpool.AOPScopedClassLoaderHelperBridge;
  | import org.jboss.mx.loading.RepositoryClassLoader;
  | import org.jboss.mx.util.MBeanServerLocator;
  | 
  | /**
  |  * JBoss4Integration.<p>
  |  * 
  |  * This class and its associated classes are
  |  * for the old JBoss4 integration with the LoaderRepository<p>
  |  * 
  |  * <ul>Related Classes:
  |  * <li> {@link JBossClassPool}
  |  * <li> {@link JBossClassPoolFactory}
  |  * <li> {@link JBossScopedClassLoaderHelper}
  |  * <li> {@link LoaderRepositoryUrlUtil}
  |  * <li> {@link ScopedClassLoaderDomain}
  |  * <li> {@link ScopedJBossClassPool}
  |  * </ul>
  |  * 
  |  * @deprecated TODO JBAOP-??? need to write a JBoss5 version 
  |  * @author <a href="adrian at jboss.com">Adrian Brock</a>
  |  * @author <a href="mailto:bill at jboss.org">Bill Burke</a>
  |  * @author <a href="kabir.khan at jboss.com">Kabir Khan</a>
  |  * @version $Revision: 1.1 $
  |  */
  | @Deprecated
  | public class JBoss4Integration implements JBossIntegration
  | {
  |    /** The delegate classpool factory */
  |    private ScopedClassPoolFactory delegateClassPoolFactory;
  |    
  |    public boolean isValidClassLoader(ClassLoader loader)
  |    {
  |       if (!(loader instanceof RepositoryClassLoader)) return false;
  |       return ((RepositoryClassLoader) loader).getLoaderRepository() != null;
  |    }
  | 
  |    public AOPClassLoaderScopingPolicy createAOPClassLoaderScopingPolicy()
  |    {
  |       AOPScopedClassLoaderHelper helper = new JBossScopedClassLoaderHelper();
  |       return new AOPScopedClassLoaderHelperBridge(helper);
  |    }
  | 
  |    public ScopedClassPoolFactory createScopedClassPoolFactory(File tmpDir) throws Exception
  |    {
  |       delegateClassPoolFactory = new JBossClassPoolFactory(tmpDir);
  |       return this;
  |    }
  |    
  |    public ScopedClassPool create(ClassLoader cl, ClassPool src, ScopedClassPoolRepository repository)
  |    {
  |       return delegateClassPoolFactory.create(cl, src, repository);
  |    }
  | 
  |    public ScopedClassPool create(ClassPool src, ScopedClassPoolRepository repository)
  |    {
  |       return delegateClassPoolFactory.create(src, repository);
  |    }
  |    
  |    public void attachDeprecatedTranslator()
  |    {
  |       AspectManager mgr = AspectManager.instance();
  |       MBeanServer server = MBeanServerLocator.locateJBoss();
  |       try
  |       {
  |          server.setAttribute(AspectManagerService.DEFAULT_LOADER_REPOSITORY, new Attribute("Translator", mgr));
  |       }
  |       catch (InstanceNotFoundException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (AttributeNotFoundException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (InvalidAttributeValueException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (MBeanException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (ReflectionException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |    }
  | 
  |    public void detachDeprecatedTranslator()
  |    {
  |       MBeanServer server = MBeanServerLocator.locateJBoss();
  |       try
  |       {
  |          server.setAttribute(AspectManagerService.DEFAULT_LOADER_REPOSITORY, new Attribute("Translator", null));
  |       }
  |       catch (InstanceNotFoundException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (AttributeNotFoundException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (InvalidAttributeValueException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (MBeanException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |       catch (ReflectionException e)
  |       {
  |          throw new RuntimeException(e);
  |       }
  |    }
  | 

This is just an FYI warning, since I've committed it yet (not tested it).

The main work will be in writing a JBoss5 version that uses the new
jboss-classloading-spi instead so it can work with both the 
RepositoryClassLoader and the VFSClassLoader.

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4065456#4065456

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4065456