| /* |
| * 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.impl; |
| |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.commons.vfs2.Capability; |
| import org.apache.commons.vfs2.FileName; |
| import org.apache.commons.vfs2.FileObject; |
| import org.apache.commons.vfs2.FileSystemException; |
| import org.apache.commons.vfs2.FileSystemOptions; |
| import org.apache.commons.vfs2.FileType; |
| import org.apache.commons.vfs2.NameScope; |
| import org.apache.commons.vfs2.provider.AbstractFileName; |
| import org.apache.commons.vfs2.provider.AbstractFileSystem; |
| import org.apache.commons.vfs2.provider.DelegateFileObject; |
| |
| /** |
| * A logical file system, made up of set of junctions, or links, to files from other file systems. |
| * <p> |
| * TODO - Handle nested junctions. |
| * </p> |
| */ |
| public class VirtualFileSystem extends AbstractFileSystem { |
| private final Map<FileName, FileObject> junctions = new HashMap<>(); |
| |
| /** |
| * Constructs a new instance. |
| * |
| * @param rootFileName The root file name of this file system. |
| * @param fileSystemOptions Options to build this file system. |
| */ |
| public VirtualFileSystem(final AbstractFileName rootFileName, final FileSystemOptions fileSystemOptions) { |
| super(rootFileName, null, fileSystemOptions); |
| } |
| |
| /** |
| * Adds the capabilities of this file system. |
| */ |
| @Override |
| protected void addCapabilities(final Collection<Capability> caps) { |
| // TODO - this isn't really true |
| caps.add(Capability.ATTRIBUTES); |
| caps.add(Capability.CREATE); |
| caps.add(Capability.DELETE); |
| caps.add(Capability.GET_TYPE); |
| caps.add(Capability.JUNCTIONS); |
| caps.add(Capability.GET_LAST_MODIFIED); |
| caps.add(Capability.SET_LAST_MODIFIED_FILE); |
| caps.add(Capability.SET_LAST_MODIFIED_FOLDER); |
| caps.add(Capability.LIST_CHILDREN); |
| caps.add(Capability.READ_CONTENT); |
| caps.add(Capability.SIGNING); |
| caps.add(Capability.WRITE_CONTENT); |
| caps.add(Capability.APPEND_CONTENT); |
| } |
| |
| /** |
| * Adds a junction to this file system. |
| * |
| * @param junctionPoint The location of the junction. |
| * @param targetFile The target file to base the junction on. |
| * @throws FileSystemException if an error occurs. |
| */ |
| @Override |
| public void addJunction(final String junctionPoint, final FileObject targetFile) throws FileSystemException { |
| final FileName junctionName = getFileSystemManager().resolveName(getRootName(), junctionPoint); |
| |
| // Check for nested junction - these are not supported yet |
| if (getJunctionForFile(junctionName) != null) { |
| throw new FileSystemException("vfs.impl/nested-junction.error", junctionName); |
| } |
| |
| try { |
| // Add to junction table |
| junctions.put(junctionName, targetFile); |
| |
| // Attach to file |
| final DelegateFileObject junctionFile = (DelegateFileObject) getFileFromCache(junctionName); |
| if (junctionFile != null) { |
| junctionFile.setFile(targetFile); |
| } |
| |
| // Create ancestors of junction point |
| FileName childName = junctionName; |
| boolean done = false; |
| for (AbstractFileName parentName = (AbstractFileName) childName.getParent(); !done |
| && parentName != null; childName = parentName, parentName = (AbstractFileName) parentName |
| .getParent()) { |
| DelegateFileObject file = (DelegateFileObject) getFileFromCache(parentName); |
| if (file == null) { |
| file = new DelegateFileObject(parentName, this, null); |
| putFileToCache(file); |
| } else { |
| done = file.exists(); |
| } |
| |
| // As this is the parent of our junction it has to be a folder |
| file.attachChild(childName, FileType.FOLDER); |
| } |
| |
| // TODO - attach all cached children of the junction point to their real file |
| } catch (final Exception e) { |
| throw new FileSystemException("vfs.impl/create-junction.error", junctionName, e); |
| } |
| } |
| |
| @Override |
| public void close() { |
| super.close(); |
| junctions.clear(); |
| } |
| |
| /** |
| * Creates a file object. This method is called only if the requested file is not cached. |
| */ |
| @Override |
| protected FileObject createFile(final AbstractFileName name) throws Exception { |
| // Find the file that the name points to |
| final FileName junctionPoint = getJunctionForFile(name); |
| final FileObject file; |
| if (junctionPoint != null) { |
| // Resolve the real file |
| final FileObject junctionFile = junctions.get(junctionPoint); |
| final String relName = junctionPoint.getRelativeName(name); |
| file = junctionFile.resolveFile(relName, NameScope.DESCENDENT_OR_SELF); |
| } else { |
| file = null; |
| } |
| |
| // Return a wrapper around the file |
| return new DelegateFileObject(name, this, file); |
| } |
| |
| /** |
| * Locates the junction point for the junction containing the given file. |
| * |
| * @param name The FileName. |
| * @return the FileName where the junction occurs. |
| */ |
| private FileName getJunctionForFile(final FileName name) { |
| if (junctions.containsKey(name)) { |
| // The name points to the junction point directly |
| return name; |
| } |
| // Find matching junction |
| return junctions.keySet().stream().filter(fileName -> fileName.isDescendent(name)).findFirst().orElse(null); |
| } |
| |
| /** |
| * Removes a junction from this file system. |
| * |
| * @param junctionPoint The junction to remove. |
| * @throws FileSystemException if an error occurs. |
| */ |
| @Override |
| public void removeJunction(final String junctionPoint) throws FileSystemException { |
| final FileName junctionName = getFileSystemManager().resolveName(getRootName(), junctionPoint); |
| junctions.remove(junctionName); |
| |
| // TODO - remove from parents of junction point |
| // TODO - detach all cached children of the junction point from their real file |
| } |
| } |