Class VFSClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

org.apache.commons.vfs2.impl.VFSClassLoader

public class VFSClassLoader
extends SecureClassLoader

A class loader that can load classes and resources from a search path.

The search path can consist of VFS FileObjects referring both to folders and JAR files. Any FileObject of type FileType.FILE is assumed to be a JAR and is opened by creating a layered file system with the "jar" scheme.

TODO - Test this with signed Jars and a SecurityManager.

See Also:

• FileSystemManager.createFileSystem(org.apache.commons.vfs2.FileObject)

Constructor Summary

Constructors

Constructor	Description
VFSClassLoader(FileObject[] files, FileSystemManager manager)	Constructors a new VFSClassLoader for the given files.
VFSClassLoader(FileObject[] files, FileSystemManager manager, ClassLoader parent)	Constructors a new VFSClassLoader for the given FileObjects.
VFSClassLoader(FileObject file, FileSystemManager manager)	Constructors a new VFSClassLoader for the given file.
VFSClassLoader(FileObject file, FileSystemManager manager, ClassLoader parent)	Constructors a new VFSClassLoader for the given file.

Method Summary

Modifier and Type	Method	Description
protected void	copyPermissions(PermissionCollection src, PermissionCollection dest)	Copies the permissions from src to dest.
protected Class<?>	findClass(String name)	Finds and loads the class with the specified name from the search path.
protected URL	findResource(String name)	Finds the resource with the specified name from the search path.
protected Enumeration<URL>	findResources(String name)	Returns an Enumeration of all the resources in the search path with the specified name.
FileObject[]	getFileObjects()	Provide access to the file objects this class loader represents.
protected PermissionCollection	getPermissions(CodeSource cs)	Calls super.getPermissions both for the code source and also adds the permissions granted to the parent layers.

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, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, registerAsParallelCapable, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Constructor Details

VFSClassLoader

public VFSClassLoader(FileObject file,
 FileSystemManager manager)
               throws FileSystemException

Constructors a new VFSClassLoader for the given file.

Parameters:

file - the file to load the classes and resources from.

manager - the FileManager to use when trying to create a layered Jar file system.

Throws:

FileSystemException - if an error occurs.

VFSClassLoader

public VFSClassLoader(FileObject file,
 FileSystemManager manager,
 ClassLoader parent)
               throws FileSystemException

Constructors a new VFSClassLoader for the given file.

Parameters:

file - the file to load the classes and resources from.

manager - the FileManager to use when trying to create a layered Jar file system.

parent - the parent class loader for delegation.

Throws:

FileSystemException - if an error occurs.

VFSClassLoader

public VFSClassLoader(FileObject[] files,
 FileSystemManager manager)
               throws FileSystemException

Constructors a new VFSClassLoader for the given files. The files will be searched in the order specified.

Parameters:

files - the files to load the classes and resources from.

manager - the FileManager to use when trying to create a layered Jar file system.

Throws:

FileSystemException - if an error occurs.

VFSClassLoader

public VFSClassLoader(FileObject[] files,
 FileSystemManager manager,
 ClassLoader parent)
               throws FileSystemException

Constructors a new VFSClassLoader for the given FileObjects. The FileObjects will be searched in the order specified.

Parameters:

files - the FileObjects to load the classes and resources from.

manager - the FileManager to use when trying to create a layered Jar file system.

parent - the parent class loader for delegation.

Throws:

FileSystemException - if an error occurs.

Method Details

copyPermissions

protected void copyPermissions(PermissionCollection src,
 PermissionCollection dest)

Copies the permissions from src to dest.

Parameters:

src - The source PermissionCollection.

dest - The destination PermissionCollection.

findClass

protected Class<?> findClass(String name)
                      throws ClassNotFoundException

Finds and loads the class with the specified name from the search path.

Overrides:

findClass in class ClassLoader

Throws:

ClassNotFoundException - if the class is not found.

findResource

protected URL findResource(String name)

Finds the resource with the specified name from the search path. This returns null if the resource is not found.

Overrides:

findResource in class ClassLoader

Parameters:

name - The resource name.

Returns:

The URL that matches the resource.

findResources

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

Returns an Enumeration of all the resources in the search path with the specified name.

Gets called from ClassLoader.getResources(String) after parent class loader was questioned.

Overrides:

findResources in class ClassLoader

Parameters:

name - The resources to find.

Returns:

An Enumeration of the resources associated with the name.

Throws:

FileSystemException - if an error occurs.

IOException

getFileObjects

public FileObject[] getFileObjects()

Provide access to the file objects this class loader represents.

Returns:

An array of FileObjects.

Since:

2.0

getPermissions

protected PermissionCollection getPermissions(CodeSource cs)

Calls super.getPermissions both for the code source and also adds the permissions granted to the parent layers.

Overrides:

getPermissions in class SecureClassLoader

Parameters:

cs - the CodeSource.

Returns:

The PermissionCollections.