| /* |
| * 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 org.apache.commons.vfs2.FileName; |
| import org.apache.commons.vfs2.FileObject; |
| import org.apache.commons.vfs2.FileSystem; |
| import org.apache.commons.vfs2.FileSystemException; |
| import org.apache.commons.vfs2.FileSystemOptions; |
| |
| /** |
| * A {@link FileProvider} that is layered on top of another, such as the contents of a zip or tar file. |
| */ |
| public abstract class AbstractLayeredFileProvider extends AbstractFileProvider { |
| |
| public AbstractLayeredFileProvider() { |
| setFileNameParser(LayeredFileNameParser.getInstance()); |
| } |
| |
| /** |
| * Locates a file object, by absolute URI. |
| * |
| * @param baseFile The base FileObject. |
| * @param uri The name of the file to locate. |
| * @param fileSystemOptions The FileSystemOptions. |
| * @return The FileObject if it is located, null otherwise. |
| * @throws FileSystemException if an error occurs. |
| */ |
| @Override |
| public FileObject findFile(final FileObject baseFile, final String uri, final FileSystemOptions fileSystemOptions) |
| throws FileSystemException { |
| // Split the URI up into its parts |
| final LayeredFileName name = (LayeredFileName) parseUri(baseFile != null ? baseFile.getName() : null, uri); |
| |
| // Make the URI canonical |
| |
| // Resolve the outer file name |
| final FileName fileName = name.getOuterName(); |
| final FileObject file = getContext().resolveFile(baseFile, fileName.getURI(), fileSystemOptions); |
| |
| // Create the file system |
| final FileObject rootFile = createFileSystem(name.getScheme(), file, fileSystemOptions); |
| |
| // Resolve the file |
| return rootFile.resolveFile(name.getPath()); |
| } |
| |
| /** |
| * Creates a layered file system. |
| * |
| * @param scheme The protocol to use. |
| * @param file a FileObject. |
| * @param fileSystemOptions Options to access the FileSystem. |
| * @return A FileObject associated with the new FileSystem. |
| * @throws FileSystemException if an error occurs. |
| */ |
| @Override |
| public synchronized FileObject createFileSystem(final String scheme, final FileObject file, |
| final FileSystemOptions fileSystemOptions) throws FileSystemException { |
| // Check if cached |
| final FileName rootName = file.getName(); |
| FileSystem fs = findFileSystem(rootName, fileSystemOptions); |
| if (fs == null) { |
| // Create the file system |
| fs = doCreateFileSystem(scheme, file, fileSystemOptions); |
| addFileSystem(rootName, fs); |
| } |
| return fs.getRoot(); |
| } |
| |
| /** |
| * Creates a layered file system. |
| * <p> |
| * This method is called if the file system is not cached. |
| * </p> |
| * |
| * @param scheme The URI scheme. |
| * @param file The file to create the file system on top of. |
| * @param fileSystemOptions options for new and underlying file systems. |
| * @return The file system, never null. Might implement {@link VfsComponent}. |
| * @throws FileSystemException if the file system cannot be created. |
| */ |
| protected abstract FileSystem doCreateFileSystem(final String scheme, final FileObject file, |
| final FileSystemOptions fileSystemOptions) throws FileSystemException; |
| |
| } |