Package org.apache.commons.vfs2.impl

Class VFSClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

org.apache.commons.vfs2.impl.VFSClassLoader

public class VFSClassLoader
extends java.security.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(java.lang.String, 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, java.lang.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, java.lang.ClassLoader parent)	Constructors a new VFSClassLoader for the given file.

Method Summary

Modifier and Type	Method	Description
protected void	copyPermissions(java.security.PermissionCollection src, java.security.PermissionCollection dest)	Copies the permissions from src to dest.
protected java.lang.Class<?>	findClass(java.lang.String name)	Finds and loads the class with the specified name from the search path.
protected java.net.URL	findResource(java.lang.String name)	Finds the resource with the specified name from the search path.
protected java.util.Enumeration<java.net.URL>	findResources(java.lang.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 java.security.PermissionCollection	getPermissions(java.security.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.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findSystemClass, getClassLoadingLock, getDefinedPackage, getDefinedPackages, getName, getPackage, getPackages, getParent, getPlatformClassLoader, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, getUnnamedModule, isRegisteredAsParallelCapable, loadClass, loadClass, registerAsParallelCapable, resolveClass, resources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass

Constructor Detail

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 create a layered Jar file system.

Throws:

FileSystemException - if an error occurs.

VFSClassLoader

public VFSClassLoader(FileObject file,
                      FileSystemManager manager,
                      java.lang.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 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 create a layered Jar file system.

Throws:

FileSystemException - if an error occurs.

VFSClassLoader

public VFSClassLoader(FileObject[] files,
                      FileSystemManager manager,
                      java.lang.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 create a layered Jar file system.

parent - the parent class loader for delegation.

Throws:

FileSystemException - if an error occurs.

Method Detail

getFileObjects

public FileObject[] getFileObjects()

Provide access to the file objects this class loader represents.

Returns:

An array of FileObjects.

Since:

2.0

findClass

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

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

Overrides:

findClass in class java.lang.ClassLoader

Throws:

java.lang.ClassNotFoundException - if the class is not found.

getPermissions

protected java.security.PermissionCollection getPermissions(java.security.CodeSource cs)

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

Overrides:

getPermissions in class java.security.SecureClassLoader

Parameters:

cs - the CodeSource.

Returns:

The PermissionCollections.

copyPermissions

protected void copyPermissions(java.security.PermissionCollection src,
                               java.security.PermissionCollection dest)

Copies the permissions from src to dest.

Parameters:

src - The source PermissionCollection.

dest - The destination PermissionCollection.

findResource

protected java.net.URL findResource(java.lang.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 java.lang.ClassLoader

Parameters:

name - The resource name.

Returns:

The URL that matches the resource.

findResources

protected java.util.Enumeration<java.net.URL> findResources(java.lang.String name)
                                                     throws java.io.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 java.lang.ClassLoader

Parameters:

name - The resources to find.

Returns:

An Enumeration of the resources associated with the name.

Throws:

FileSystemException - if an error occurs.

java.io.IOException