org.jboss.deployment.scope
Class Scope

java.lang.Object
  |
  +--org.jboss.deployment.scope.Scope

public class Scope

extends java.lang.Object

Scope is a manager/mediator that connects several ScopedURLClassLoaders with each other and computes their dependencies. The locks used in the scope implementation are quite coarse-grained, maybe thread-unfriendly, but the rationale is that classloading a) happens not too often (hopefully) in the lifecycle of an application b) will dispatch only in special cases (where applications depliberately share classes) to this scope class and c) is optimized by caching the locations.

Version:

0.8

Author:

cgjung

Field Summary

protected java.util.Map	classLoaders keeps a map of class loaders that participate in this scope
protected java.util.Map	classLocations keeps a hashtable of class appearances
protected java.util.Map	dependencies keeps a hashtable of dependencies between the classLoaders
protected Logger	log keeps a reference to a logger which which to interact
protected java.util.Map	resourceLocations keeps a hashtable of resource appearances

Constructor Summary

Scope(Logger log)
Creates new Scope

Method Summary

protected boolean	addDependency(ScopedURLClassLoader source, ScopedURLClassLoader target) adds a dependency between two classloaders.
protected void	clearByValue(java.util.Map map, java.lang.Object value) helper method that will clear all entries from a map with a dedicated target value.
ScopedURLClassLoader	deRegisterClassLoader(ScopedURLClassLoader loader) deRegisters a classloader in this scope removes all cached data related to this classloader
java.util.Set	getDependentClassLoaders(ScopedURLClassLoader loader) returns the classLoaders that a particular classLoader is dependent on.
java.net.URL	getResource(java.lang.String name, ScopedURLClassLoader source) gets a URL on behalf of a given classloader which may be null in case that we do not check dependencies
java.lang.Class	loadClass(java.lang.String className, boolean resolve, ScopedURLClassLoader source) loads a class on behalf of a given classloader
ScopedURLClassLoader	registerClassLoader(ScopedURLClassLoader loader) registers a classloader in this scope

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

classLoaders

protected final java.util.Map classLoaders

keeps a map of class loaders that participate in this scope

dependencies

protected final java.util.Map dependencies

keeps a hashtable of dependencies between the classLoaders

classLocations

protected final java.util.Map classLocations

keeps a hashtable of class appearances

resourceLocations

protected final java.util.Map resourceLocations

keeps a hashtable of resource appearances

log

protected final Logger log

keeps a reference to a logger which which to interact

Constructor Detail

Scope

public Scope(Logger log)

Creates new Scope

Method Detail

registerClassLoader

public ScopedURLClassLoader registerClassLoader(ScopedURLClassLoader loader)

registers a classloader in this scope

deRegisterClassLoader

public ScopedURLClassLoader deRegisterClassLoader(ScopedURLClassLoader loader)

deRegisters a classloader in this scope removes all cached data related to this classloader

clearByValue

protected void clearByValue(java.util.Map map,
                            java.lang.Object value)

helper method that will clear all entries from a map with a dedicated target value.

getDependentClassLoaders

public java.util.Set getDependentClassLoaders(ScopedURLClassLoader loader)

returns the classLoaders that a particular classLoader is dependent on. Should be called after locking classLoaders

addDependency

protected boolean addDependency(ScopedURLClassLoader source,
                                ScopedURLClassLoader target)

adds a dependency between two classloaders. this can be called from within application threads that require resource loading. Should be called after locking classLoaders

loadClass

public java.lang.Class loadClass(java.lang.String className,
                                 boolean resolve,
                                 ScopedURLClassLoader source)
                          throws java.lang.ClassNotFoundException

loads a class on behalf of a given classloader

getResource

public java.net.URL getResource(java.lang.String name,
                                ScopedURLClassLoader source)

gets a URL on behalf of a given classloader which may be null in case that we do not check dependencies