org.apache.commons.vfs.provider
Class AbstractFileSystem

java.lang.Object
  org.apache.commons.vfs.provider.AbstractVfsComponent
      org.apache.commons.vfs.provider.AbstractFileSystem

All Implemented Interfaces:

FileSystem, VfsComponent

Direct Known Subclasses:

CompressedFileFileSystem, FtpFileSystem, HttpFileSystem, LocalFileSystem, RamFileSystem, SftpFileSystem, TarFileSystem, UrlFileSystem, VirtualFileSystem, ZipFileSystem

public abstract class AbstractFileSystem
extends AbstractVfsComponent
implements FileSystem

A partial FileSystem implementation.

Version:

$Revision: 484648 $ $Date: 2006-12-08 17:18:36 +0100 (Fr, 08 Dez 2006) $

Author:

Adam Murdoch

Field Summary

private FileSystemKey	cacheKey
private java.util.Collection	caps
private FileSystemOptions	fileSystemOptions FileSystemOptions used for configuration
private java.util.Map	listenerMap Map from FileName to an ArrayList of listeners for that file.
private static org.apache.commons.logging.Log	log
private int	openStreams open streams counter for this filesystem
private FileObject	parentLayer
private FileName	rootName
private long	useCount How many fileObjects are handed out

Constructor Summary

protected

AbstractFileSystem(FileName rootName, FileObject parentLayer, FileSystemOptions fileSystemOptions)

Method Summary

protected abstract void	addCapabilities(java.util.Collection caps) Adds the capabilities of this file system.
void	addJunction(java.lang.String junctionPoint, FileObject targetFile) Adds a junction to this file system.
void	addListener(FileObject file, FileListener listener) Adds a listener on a file in this file system.
void	close() Closes this component.
void	closeCommunicationLink() Close the underlaying link used to access the files
protected abstract FileObject	createFile(FileName name) Creates a file object.
protected FileObject	decorateFileObject(FileObject file)
protected void	doCloseCommunicationLink() Close the underlaying link used to access the files
protected java.io.File	doReplicateFile(FileObject file, FileSelector selector) Creates a temporary local copy of a file and its descendents.
(package private) void	fileObjectDestroyed(FileObject fileObject)
(package private) void	fileObjectHanded(FileObject fileObject)
private void	fireEvent(AbstractFileChangeEvent event) Fires an event.
void	fireFileChanged(FileObject file) Fires a file changed event.
void	fireFileCreated(FileObject file) Fires a file create event.
void	fireFileDeleted(FileObject file) Fires a file delete event.
(package private) void	freeResources()
java.lang.Object	getAttribute(java.lang.String attrName) Retrieves the attribute with the specified name.
private FilesCache	getCache()
(package private) FileSystemKey	getCacheKey()
protected FileObject	getFileFromCache(FileName name) Returns a cached file.
FileSystemManager	getFileSystemManager() Return the FileSystemManager used to instantiate this filesystem
FileSystemOptions	getFileSystemOptions() Return the FileSystemOptions used to instantiate this filesystem
double	getLastModTimeAccuracy() Returns the accuracy of the last modification time
FileObject	getParentLayer() Returns the parent layer if this is a layered file system.
FileObject	getRoot() Returns the root file of this file system.
FileName	getRootName() Returns the name of the root of this file system.
boolean	hasCapability(Capability capability) Determines if this file system has a particular capability.
void	init() Initialises this component.
boolean	isOpen() check if this filesystem has open streams
boolean	isReleaseable() returns true if no file is using this filesystem
protected void	notifyAllStreamsClosed() will be called after all file-objects closed their streams.
protected void	putFileToCache(FileObject file) Adds a file object to the cache.
protected void	removeFileFromCache(FileName name) remove a cached file.
void	removeJunction(java.lang.String junctionPoint) Removes a junction from this file system.
void	removeListener(FileObject file, FileListener listener) Removes a listener from a file in this file system.
java.io.File	replicateFile(FileObject file, FileSelector selector) Creates a temporary local copy of a file and its descendents.
FileObject	resolveFile(FileName name) Finds a file in this file system.
private FileObject	resolveFile(FileName name, boolean useCache)
FileObject	resolveFile(java.lang.String nameStr) Finds a file in this file system.
void	setAttribute(java.lang.String attrName, java.lang.Object value) Sets the attribute with the specified name.
(package private) void	setCacheKey(FileSystemKey cacheKey)
(package private) void	streamClosed()
(package private) void	streamOpened()

Methods inherited from class org.apache.commons.vfs.provider.AbstractVfsComponent

getContext, getLogger, setContext, setLogger

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final org.apache.commons.logging.Log log

rootName

private final FileName rootName

parentLayer

private FileObject parentLayer

caps

private final java.util.Collection caps

listenerMap

private final java.util.Map listenerMap

Map from FileName to an ArrayList of listeners for that file.

fileSystemOptions

private final FileSystemOptions fileSystemOptions

FileSystemOptions used for configuration

useCount

private long useCount

How many fileObjects are handed out

cacheKey

private FileSystemKey cacheKey

openStreams

private int openStreams

open streams counter for this filesystem

Constructor Detail

AbstractFileSystem

protected AbstractFileSystem(FileName rootName,
                             FileObject parentLayer,
                             FileSystemOptions fileSystemOptions)

Method Detail

init

public void init()
          throws FileSystemException

Initialises this component.

Specified by:

init in interface VfsComponent

Overrides:

init in class AbstractVfsComponent

Throws:

FileSystemException

close

public void close()

Closes this component.

Specified by:

close in interface VfsComponent

Overrides:

close in class AbstractVfsComponent

closeCommunicationLink

public void closeCommunicationLink()

Close the underlaying link used to access the files

doCloseCommunicationLink

protected void doCloseCommunicationLink()

Close the underlaying link used to access the files

createFile

protected abstract FileObject createFile(FileName name)
                                  throws java.lang.Exception

Creates a file object. This method is called only if the requested file is not cached.

Throws:

java.lang.Exception

addCapabilities

protected abstract void addCapabilities(java.util.Collection caps)

Adds the capabilities of this file system.

getRootName

public FileName getRootName()

Returns the name of the root of this file system.

Specified by:

getRootName in interface FileSystem

putFileToCache

protected void putFileToCache(FileObject file)

Adds a file object to the cache.

getCache

private FilesCache getCache()

getFileFromCache

protected FileObject getFileFromCache(FileName name)

Returns a cached file.

removeFileFromCache

protected void removeFileFromCache(FileName name)

remove a cached file.

hasCapability

public boolean hasCapability(Capability capability)

Determines if this file system has a particular capability.

Specified by:

hasCapability in interface FileSystem

Parameters:

capability - The capability to check for.

Returns:

true if this filesystem has the requested capability. Note that not all files in the file system may have the capability.

getAttribute

public java.lang.Object getAttribute(java.lang.String attrName)
                              throws FileSystemException

Retrieves the attribute with the specified name. The default implementation simply throws an exception.

Specified by:

getAttribute in interface FileSystem

Parameters:

attrName - The name of the attribute.

Returns:

The value of the attribute.

Throws:

FileSystemException - If the file does not exist, or is being written, or if the attribute is unknown.

See Also:

FileContent.getAttribute(java.lang.String)

setAttribute

public void setAttribute(java.lang.String attrName,
                         java.lang.Object value)
                  throws FileSystemException

Sets the attribute with the specified name. The default implementation simply throws an exception.

Specified by:

setAttribute in interface FileSystem

Parameters:

attrName - The name of the attribute.

value - The value of the attribute.

Throws:

FileSystemException - If the file is read-only, or is being read, or if the attribute is not supported, or on error setting the attribute.

See Also:

FileContent.setAttribute(java.lang.String, java.lang.Object)

getParentLayer

public FileObject getParentLayer()
                          throws FileSystemException

Returns the parent layer if this is a layered file system.

Specified by:

getParentLayer in interface FileSystem

Returns:

The parent layer, or null if this is not a layered file system.

Throws:

FileSystemException

getRoot

public FileObject getRoot()
                   throws FileSystemException

Returns the root file of this file system.

Specified by:

getRoot in interface FileSystem

Throws:

FileSystemException

resolveFile

public FileObject resolveFile(java.lang.String nameStr)
                       throws FileSystemException

Finds a file in this file system.

Specified by:

resolveFile in interface FileSystem

Parameters:

nameStr - The name of the file. This must be an absolute path.

Returns:

The file. Never returns null.

Throws:

FileSystemException

resolveFile

public FileObject resolveFile(FileName name)
                       throws FileSystemException

Finds a file in this file system.

Specified by:

resolveFile in interface FileSystem

Parameters:

name - The name of the file.

Returns:

The file. Never returns null.

Throws:

FileSystemException

resolveFile

private FileObject resolveFile(FileName name,
                               boolean useCache)
                        throws FileSystemException

Throws:

FileSystemException

decorateFileObject

protected FileObject decorateFileObject(FileObject file)
                                 throws FileSystemException

Throws:

FileSystemException

replicateFile

public java.io.File replicateFile(FileObject file,
                                  FileSelector selector)
                           throws FileSystemException

Creates a temporary local copy of a file and its descendents.

Specified by:

replicateFile in interface FileSystem

Parameters:

file - The file to replicate.

selector - The selector to use to select the files to replicate.

Returns:

The local copy of this file.

Throws:

FileSystemException - If this file does not exist, or on error replicating the file.

getFileSystemOptions

public FileSystemOptions getFileSystemOptions()

Return the FileSystemOptions used to instantiate this filesystem

Specified by:

getFileSystemOptions in interface FileSystem

getFileSystemManager

public FileSystemManager getFileSystemManager()

Return the FileSystemManager used to instantiate this filesystem

Specified by:

getFileSystemManager in interface FileSystem

getLastModTimeAccuracy

public double getLastModTimeAccuracy()

Returns the accuracy of the last modification time

Specified by:

getLastModTimeAccuracy in interface FileSystem

Returns:

ms 0 perfectly accurate, >0 might be off by this value e.g. sftp 1000ms

doReplicateFile

protected java.io.File doReplicateFile(FileObject file,
                                       FileSelector selector)
                                throws java.lang.Exception

Creates a temporary local copy of a file and its descendents.

Throws:

java.lang.Exception

addJunction

public void addJunction(java.lang.String junctionPoint,
                        FileObject targetFile)
                 throws FileSystemException

Adds a junction to this file system.

Specified by:

addJunction in interface FileSystem

Parameters:

junctionPoint - The point in this file system to add the junction.

targetFile - The file to link to.

Throws:

FileSystemException - If this file system does not support junctions, or the junction point or target file is invalid (the file system may not support nested junctions, for example).

removeJunction

public void removeJunction(java.lang.String junctionPoint)
                    throws FileSystemException

Removes a junction from this file system.

Specified by:

removeJunction in interface FileSystem

Parameters:

junctionPoint - The junction to remove.

Throws:

FileSystemException - On error removing the junction.

addListener

public void addListener(FileObject file,
                        FileListener listener)

Adds a listener on a file in this file system.

Specified by:

addListener in interface FileSystem

Parameters:

file - The file to attach the listener to.

listener - The listener to add.

removeListener

public void removeListener(FileObject file,
                           FileListener listener)

Removes a listener from a file in this file system.

Specified by:

removeListener in interface FileSystem

Parameters:

file - The file to remove the listener from.

listener - The listener to remove.

fireFileCreated

public void fireFileCreated(FileObject file)

Fires a file create event.

fireFileDeleted

public void fireFileDeleted(FileObject file)

Fires a file delete event.

fireFileChanged

public void fireFileChanged(FileObject file)

Fires a file changed event.
This will only happen if you monitor the file using FileMonitor.

isReleaseable

public boolean isReleaseable()

returns true if no file is using this filesystem

freeResources

void freeResources()

fireEvent

private void fireEvent(AbstractFileChangeEvent event)

Fires an event.

fileObjectHanded

void fileObjectHanded(FileObject fileObject)

fileObjectDestroyed

void fileObjectDestroyed(FileObject fileObject)

setCacheKey

void setCacheKey(FileSystemKey cacheKey)

getCacheKey

FileSystemKey getCacheKey()

streamOpened

void streamOpened()

streamClosed

void streamClosed()

notifyAllStreamsClosed

protected void notifyAllStreamsClosed()

will be called after all file-objects closed their streams.

isOpen

public boolean isOpen()

check if this filesystem has open streams