org.mule.runtime.module.artifact.api.classloader

Class MuleArtifactClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.mule.runtime.module.artifact.api.classloader.FineGrainedControlClassLoader

org.mule.runtime.module.artifact.api.classloader.MuleArtifactClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable, ArtifactClassLoader, ClassLoaderLookupPolicyProvider, DisposableClassLoader, LocalResourceLocator

Direct Known Subclasses:

MuleDeployableArtifactClassLoader

public class MuleArtifactClassLoader
extends FineGrainedControlClassLoader
implements ArtifactClassLoader

Abstract implementation of the ArtifactClassLoader interface, that manages shutdown listeners.

Nested Class Summary

Nested classes/interfaces inherited from class org.mule.runtime.module.artifact.api.classloader.FineGrainedControlClassLoader

FineGrainedControlClassLoader.NonCachingURLStreamHandlerFactory

Field Summary

Fields

Modifier and Type	Field and Description
protected List<ShutdownListener>	shutdownListeners

Constructor Summary

Constructors

Constructor and Description
MuleArtifactClassLoader(String artifactId, ArtifactDescriptor artifactDescriptor, URL[] urls, ClassLoader parent, ClassLoaderLookupPolicy lookupPolicy) Constructs a new MuleArtifactClassLoader for the given URLs

Method Summary

Modifier and Type	Method and Description
void	addShutdownListener(ShutdownListener listener) Adds a shutdown listener to the class loader.
protected ResourceReleaser	createResourceReleaserInstance() Creates a ResourceReleaser using this classloader, only used outside in unit tests.
void	dispose() Disposes the ClassLoader by closing all the resources opened by this ClassLoader.
URL	findLocalResource(String resourceName) This method finds a resource in the local environment for this artifact, if the resource is not found and the artifact has a parent artifact then the operation is resolved by that parent, if there is no parent, the resources is searched in the global environment.
<T extends ArtifactDescriptor> T	getArtifactDescriptor()
String	getArtifactId()
ClassLoader	getClassLoader() ClassLoader is an abstract class.
protected String[]	getLocalResourceLocations()
void	setResourceReleaserClassLocation(String resourceReleaserClassLocation)
String	toString()

Methods inherited from class org.mule.runtime.module.artifact.api.classloader.FineGrainedControlClassLoader

findLocalClass, findParentClass, getClassLoaderLookupPolicy, getResource, getResources, loadClass

Methods inherited from class java.net.URLClassLoader

addURL, close, definePackage, findClass, findResource, findResources, getPermissions, getResourceAsStream, getURLs, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, registerAsParallelCapable, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.mule.runtime.module.artifact.api.classloader.ArtifactClassLoader

findLocalClass, findResource, findResources

Methods inherited from interface org.mule.runtime.module.artifact.api.classloader.ClassLoaderLookupPolicyProvider

getClassLoaderLookupPolicy

Field Detail

shutdownListeners

protected List<ShutdownListener> shutdownListeners

Constructor Detail

MuleArtifactClassLoader

public MuleArtifactClassLoader(String artifactId,
                               ArtifactDescriptor artifactDescriptor,
                               URL[] urls,
                               ClassLoader parent,
                               ClassLoaderLookupPolicy lookupPolicy)

Constructs a new MuleArtifactClassLoader for the given URLs

Parameters:

artifactId - artifact unique ID. Non empty.

artifactDescriptor - descriptor for the artifact owning the created class loader. Non null.

urls - the URLs from which to load classes and resources

parent - the parent class loader for delegation

lookupPolicy - policy used to guide the lookup process. Non null

Method Detail

getArtifactId

public String getArtifactId()

Specified by:

getArtifactId in interface ArtifactClassLoader

Returns:

the artifact unique identifier

getArtifactDescriptor

public <T extends ArtifactDescriptor> T getArtifactDescriptor()

Specified by:

getArtifactDescriptor in interface ArtifactClassLoader

Type Parameters:

T - the generic type of the artifact descriptor.

Returns:

the artifact descriptor corresponding to this classloader instance. Non null.

getLocalResourceLocations

protected String[] getLocalResourceLocations()

getClassLoader

public ClassLoader getClassLoader()

Description copied from interface: ArtifactClassLoader

ClassLoader is an abstract class. Not an interface. There are parts of the code that requires a ClassLoader and others that requires an ArtifactClassLoader. Ideally I would make ArtifactClassLoader implement ClassLoader interface but there's no such interface. So if I have a method that requires a ClassLoader instance and an ArtifactClassLoader I would have to down cast and assume that it can be down casted or send two parameters, one for the ClassLoader and one for the ArtifactClassLoader: public void doSomething(ArtifactClassLoader acl) { doSomething2(acl); //this requires an ArtifactClassLoader doSomething3((ClassLoader)acl); //this requires a ClassLoader } public void doSomething(ArtifactClassLoader acl, ClassLoader cl) { doSomething2(acl); //this requires an ArtifactClassLoader doSomething3(cl); //this requires a ClassLoader } To overcome that problem seems much better to have a method in ArtifactClassLoader that can actually return a ClassLoader instance: public void doSomething(ArtifactClassLoader acl) { doSomething2(acl); //this requires an ArtifactClassLoader doSomething3(acl.getDomainClassLoader()); //this requires a ClassLoader }

Specified by:

getClassLoader in interface ArtifactClassLoader

Returns:

class loader to use for this artifact.

addShutdownListener

public void addShutdownListener(ShutdownListener listener)

Description copied from interface: ArtifactClassLoader

Adds a shutdown listener to the class loader. This listener will be invoked synchronously right before the class loader is disposed and closed.

Specified by:

addShutdownListener in interface ArtifactClassLoader

dispose

public void dispose()

Description copied from class: FineGrainedControlClassLoader

Disposes the ClassLoader by closing all the resources opened by this ClassLoader. See URLClassLoader.close().

Specified by:

dispose in interface DisposableClassLoader

Overrides:

dispose in class FineGrainedControlClassLoader

createResourceReleaserInstance

protected ResourceReleaser createResourceReleaserInstance()

Creates a ResourceReleaser using this classloader, only used outside in unit tests.

setResourceReleaserClassLocation

public void setResourceReleaserClassLocation(String resourceReleaserClassLocation)

findLocalResource

public URL findLocalResource(String resourceName)

Description copied from interface: LocalResourceLocator

This method finds a resource in the local environment for this artifact, if the resource is not found and the artifact has a parent artifact then the operation is resolved by that parent, if there is no parent, the resources is searched in the global environment.

Specified by:

findLocalResource in interface LocalResourceLocator

Parameters:

resourceName - name of the resource to find.

Returns:

the resource URL, null if it doesn't exists.

toString

public String toString()

Overrides:

toString in class Object