/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.vfs2.provider;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.cert.Certificate;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.apache.commons.vfs2.FileChangeEvent;
import org.apache.commons.vfs2.FileContentInfo;
import org.apache.commons.vfs2.FileListener;
import org.apache.commons.vfs2.FileName;
import org.apache.commons.vfs2.FileNotFolderException;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileType;
import org.apache.commons.vfs2.RandomAccessContent;
import org.apache.commons.vfs2.util.RandomAccessMode;
import org.apache.commons.vfs2.util.WeakRefFileListener;
/**
* A file backed by another file.
*
* @author <a href="http://commons.apache.org/vfs/team-list.html">Commons VFS team</a>
* @todo Extract subclass that overlays the children
*/
public class DelegateFileObject extends AbstractFileObject implements FileListener
{
private FileObject file;
private final Set<String> children = new HashSet<String>();
private boolean ignoreEvent;
public DelegateFileObject(final AbstractFileName name,
final AbstractFileSystem fileSystem,
final FileObject file) throws FileSystemException
{
super(name, fileSystem);
this.file = file;
if (file != null)
{
WeakRefFileListener.installListener(file, this);
}
}
/**
* Get access to the delegated file.
* @return The FileObject.
* @since 2.0
*/
public FileObject getDelegateFile()
{
return file;
}
/**
* Adds a child to this file.
* @param baseName The base FileName.
* @param type The FileType.
* @throws Exception if an error occurs.
*/
public void attachChild(final FileName baseName, final FileType type) throws Exception
{
final FileType oldType = doGetType();
if (children.add(baseName.getBaseName()))
{
childrenChanged(baseName, type);
}
maybeTypeChanged(oldType);
}
/**
* Attaches or detaches the target file.
* @param file The FileObject.
* @throws Exception if an error occurs.
*/
public void setFile(final FileObject file) throws Exception
{
final FileType oldType = doGetType();
if (file != null)
{
WeakRefFileListener.installListener(file, this);
}
this.file = file;
maybeTypeChanged(oldType);
}
/**
* Checks whether the file's type has changed, and fires the appropriate
* events.
* @param oldType The old FileType.
* @throws Exception if an error occurs.
*/
private void maybeTypeChanged(final FileType oldType) throws Exception
{
final FileType newType = doGetType();
if (oldType == FileType.IMAGINARY && newType != FileType.IMAGINARY)
{
handleCreate(newType);
}
else if (oldType != FileType.IMAGINARY && newType == FileType.IMAGINARY)
{
handleDelete();
}
}
/**
* Determines the type of the file, returns null if the file does not
* exist.
*/
@Override
protected FileType doGetType() throws FileSystemException
{
if (file != null)
{
return file.getType();
}
else if (children.size() > 0)
{
return FileType.FOLDER;
}
else
{
return FileType.IMAGINARY;
}
}
/**
* Determines if this file can be read.
*/
@Override
protected boolean doIsReadable() throws FileSystemException
{
if (file != null)
{
return file.isReadable();
}
else
{
return true;
}
}
/**
* Determines if this file can be written to.
*/
@Override
protected boolean doIsWriteable() throws FileSystemException
{
if (file != null)
{
return file.isWriteable();
}
else
{
return false;
}
}
/**
* Determines if this file is hidden.
*/
@Override
protected boolean doIsHidden() throws FileSystemException
{
if (file != null)
{
return file.isHidden();
}
else
{
return false;
}
}
/**
* Lists the children of the file.
*/
@Override
protected String[] doListChildren() throws Exception
{
if (file != null)
{
final FileObject[] children;
try
{
children = file.getChildren();
}
// VFS-210
catch (FileNotFolderException e)
{
throw new FileNotFolderException(getName(), e);
}
final String[] childNames = new String[children.length];
for (int i = 0; i < children.length; i++)
{
childNames[i] = children[i].getName().getBaseName();
}
return childNames;
}
else
{
return children.toArray(new String[children.size()]);
}
}
/**
* Creates this file as a folder.
*/
@Override
protected void doCreateFolder() throws Exception
{
ignoreEvent = true;
try
{
file.createFolder();
}
finally
{
ignoreEvent = false;
}
}
/**
* Deletes the file.
*/
@Override
protected void doDelete() throws Exception
{
ignoreEvent = true;
try
{
file.delete();
}
finally
{
ignoreEvent = false;
}
}
/**
* Returns the size of the file content (in bytes). Is only called if
* {@link #doGetType} returns {@link FileType#FILE}.
*/
@Override
protected long doGetContentSize() throws Exception
{
return file.getContent().getSize();
}
/**
* Returns the attributes of this file.
*/
@Override
protected Map<String, Object> doGetAttributes()
throws Exception
{
return file.getContent().getAttributes();
}
/**
* Sets an attribute of this file.
*/
@Override
protected void doSetAttribute(final String atttrName,
final Object value)
throws Exception
{
file.getContent().setAttribute(atttrName, value);
}
/**
* Returns the certificates of this file.
*/
@Override
protected Certificate[] doGetCertificates() throws Exception
{
return file.getContent().getCertificates();
}
/**
* Returns the last-modified time of this file.
*/
@Override
protected long doGetLastModifiedTime() throws Exception
{
return file.getContent().getLastModifiedTime();
}
/**
* Sets the last-modified time of this file.
* @since 2.0
*/
@Override
protected boolean doSetLastModifiedTime(final long modtime)
throws Exception
{
file.getContent().setLastModifiedTime(modtime);
return true;
}
/**
* Creates an input stream to read the file content from.
*/
@Override
protected InputStream doGetInputStream() throws Exception
{
return file.getContent().getInputStream();
}
/**
* Creates an output stream to write the file content to.
*/
@Override
protected OutputStream doGetOutputStream(boolean bAppend) throws Exception
{
return file.getContent().getOutputStream(bAppend);
}
/**
* Called when a file is created.
* @param event The FileChangeEvent.
* @throws Exception if an error occurs.
*/
public void fileCreated(final FileChangeEvent event) throws Exception
{
if (event.getFile() != file)
{
return;
}
if (!ignoreEvent)
{
handleCreate(file.getType());
}
}
/**
* Called when a file is deleted.
* @param event The FileChangeEvent.
* @throws Exception if an error occurs.
*/
public void fileDeleted(final FileChangeEvent event) throws Exception
{
if (event.getFile() != file)
{
return;
}
if (!ignoreEvent)
{
handleDelete();
}
}
/**
* Called when a file is changed.
* <p/>
* This will only happen if you monitor the file using {@link org.apache.commons.vfs2.FileMonitor}.
* @param event The FileChangeEvent.
* @throws Exception if an error occurs.
*/
public void fileChanged(FileChangeEvent event) throws Exception
{
if (event.getFile() != file)
{
return;
}
if (!ignoreEvent)
{
handleChanged();
}
}
/**
* Close the delegated file.
* @throws FileSystemException if an error occurs.
*/
@Override
public void close() throws FileSystemException
{
super.close();
if (file != null)
{
file.close();
}
}
/**
* Refresh file information.
* @throws FileSystemException if an error occurs.
* @since 2.0
*/
@Override
public void refresh() throws FileSystemException
{
super.refresh();
if (file != null)
{
file.refresh();
}
}
/** @since 2.0 */
protected FileContentInfo doGetContentInfo() throws Exception
{
return file.getContent().getContentInfo();
}
/**
* Renames the file.
* @since 2.0
*/
@Override
protected void doRename(FileObject newFile)
throws Exception
{
file.moveTo(((DelegateFileObject) newFile).file);
}
/**
* Removes an attribute of this file.
* @since 2.0
*/
@Override
protected void doRemoveAttribute(final String atttrName)
throws Exception
{
file.getContent().removeAttribute(atttrName);
}
/**
* Creates access to the file for random i/o.
* @since 2.0
*/
@Override
protected RandomAccessContent doGetRandomAccessContent(final RandomAccessMode mode) throws Exception
{
return file.getContent().getRandomAccessContent(mode);
}
}