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

Class FilteringArtifactClassLoader

java.lang.Object

java.lang.ClassLoader

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

All Implemented Interfaces:

ArtifactClassLoader, ClassLoaderLookupPolicyProvider, DisposableClassLoader, LocalResourceLocator

@NoInstantiate
public class FilteringArtifactClassLoader
extends ClassLoader
implements ArtifactClassLoader

Defines a ClassLoader that filter which classes and resources can be resolved based on a ClassLoaderFilter

Resources used to provide SPI are not managed as standard resources, ie, not filtered through the ClassLoaderFilter, but filtered using ExportedService definitions. Only the service providers defined as exported in the modules will be available from this class loader.

Constructor Summary

Constructors

Constructor and Description
FilteringArtifactClassLoader(ArtifactClassLoader artifactClassLoader, ClassLoaderFilter filter, List<ExportedService> exportedServices) Creates a new filtering classLoader

Method Summary

Modifier and Type	Method and Description
void	addShutdownListener(ShutdownListener listener) Adds a shutdown listener to the class loader.
void	dispose() Gets rid of the class loader resources.
Class<?>	findLocalClass(String name) Loads the class with the specified binary name if defined on this class loader.
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.
URL	findResource(String name)
Enumeration<URL>	findResources(String name) Returns an enumeration of URL objects representing all the resources with the given name which are local to the classloader
<T extends ArtifactDescriptor> T	getArtifactDescriptor()
String	getArtifactId()
ClassLoader	getClassLoader() ClassLoader is an abstract class.
ClassLoaderLookupPolicy	getClassLoaderLookupPolicy()
URL	getResource(String name)
protected URL	getResourceFromDelegate(ArtifactClassLoader artifactClassLoader, String name)
Enumeration<URL>	getResources(String name)
protected Enumeration<URL>	getResourcesFromDelegate(ArtifactClassLoader artifactClassLoader, String name)
Class<?>	loadClass(String name)
String	toString()

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getResourceAsStream, 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

Constructor Detail

FilteringArtifactClassLoader

public FilteringArtifactClassLoader(ArtifactClassLoader artifactClassLoader,
                                    ClassLoaderFilter filter,
                                    List<ExportedService> exportedServices)

Creates a new filtering classLoader

Parameters:

artifactClassLoader - artifact classLoader to filter. Non null

filter - filters access to classes and resources from the artifact classLoader. Non null

exportedServices - service providers that will be available from the filtered class loader. Non null.

Method Detail

loadClass

public Class<?> loadClass(String name)
                   throws ClassNotFoundException

Overrides:

loadClass in class ClassLoader

Throws:

ClassNotFoundException

getResource

public URL getResource(String name)

Overrides:

getResource in class ClassLoader

getResourceFromDelegate

protected URL getResourceFromDelegate(ArtifactClassLoader artifactClassLoader,
                                      String name)

getResources

public Enumeration<URL> getResources(String name)
                              throws IOException

Overrides:

getResources in class ClassLoader

Throws:

IOException

getResourcesFromDelegate

protected Enumeration<URL> getResourcesFromDelegate(ArtifactClassLoader artifactClassLoader,
                                                    String name)
                                             throws IOException

Throws:

IOException

findResource

public URL findResource(String name)

Specified by:

findResource in interface ArtifactClassLoader

Overrides:

findResource in class ClassLoader

Parameters:

name - name of the resource to find.

Returns:

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

findResources

public Enumeration<URL> findResources(String name)
                               throws IOException

Description copied from interface: ArtifactClassLoader

Returns an enumeration of URL objects representing all the resources with the given name which are local to the classloader

Specified by:

findResources in interface ArtifactClassLoader

Overrides:

findResources in class ClassLoader

Parameters:

name - The resource name

Returns:

An enumeration of URL objects for the resources

Throws:

IOException - If I/O errors occur

findLocalClass

public Class<?> findLocalClass(String name)
                        throws ClassNotFoundException

Description copied from interface: ArtifactClassLoader

Loads the class with the specified binary name if defined on this class loader.

Specified by:

findLocalClass in interface ArtifactClassLoader

Parameters:

name - The binary name of the class

Returns:

The resulting Class object

Throws:

ClassNotFoundException - If the class was not found

toString

public String toString()

Overrides:

toString in class Object

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.

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

getClassLoaderLookupPolicy

public ClassLoaderLookupPolicy getClassLoaderLookupPolicy()

Specified by:

getClassLoaderLookupPolicy in interface ClassLoaderLookupPolicyProvider

Returns:

lookup policy used on the classLoader. Non null.

dispose

public void dispose()

Description copied from interface: DisposableClassLoader

Gets rid of the class loader resources.

Specified by:

dispose in interface DisposableClassLoader

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.