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/*
 * 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.
 * 

* TODO - Extract subclass that overlays the children. * * @param A subclass of AbstractFileSystem. */ public class DelegateFileObject extends AbstractFileObject implements FileListener { private FileObject file; private final Set children = new HashSet<>(); private boolean ignoreEvent; public DelegateFileObject(final AbstractFileName name, final AFS 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(); } return true; } /** * Determines if this file can be written to. */ @Override protected boolean doIsWriteable() throws FileSystemException { if (file != null) { return file.isWriteable(); } return false; } /** * Determines if this file is executable. */ @Override protected boolean doIsExecutable() throws FileSystemException { if (file != null) { return file.isExecutable(); } return false; } /** * Determines if this file is hidden. */ @Override protected boolean doIsHidden() throws FileSystemException { if (file != null) { return file.isHidden(); } 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 (final 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; } 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 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(final 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. */ @Override 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. */ @Override public void fileDeleted(final FileChangeEvent event) throws Exception { if (event.getFile() != file) { return; } if (!ignoreEvent) { handleDelete(); } } /** * Called when a file is changed. *

* 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. */ @Override public void fileChanged(final 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(); } } /** * Return file content info. * * @return the file content info of the delegee. * @throws Exception Any thrown Exception is wrapped in FileSystemException. * @since 2.0 */ protected FileContentInfo doGetContentInfo() throws Exception { return file.getContent().getContentInfo(); } /** * Renames the file. * * @param newFile the new location/name. * @throws Exception Any thrown Exception is wrapped in FileSystemException. * @since 2.0 */ @Override protected void doRename(final 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); } }





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