001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.vfs2.provider.compressed;
018
019import java.util.Collection;
020
021import org.apache.commons.vfs2.Capability;
022import org.apache.commons.vfs2.FileName;
023import org.apache.commons.vfs2.FileObject;
024import org.apache.commons.vfs2.FileSystem;
025import org.apache.commons.vfs2.FileSystemException;
026import org.apache.commons.vfs2.FileSystemOptions;
027import org.apache.commons.vfs2.FileType;
028import org.apache.commons.vfs2.provider.AbstractLayeredFileProvider;
029import org.apache.commons.vfs2.provider.LayeredFileName;
030
031/**
032 * A file system provider for compressed files. Provides read-only file systems.
033 */
034public abstract class CompressedFileFileProvider extends AbstractLayeredFileProvider {
035
036    /**
037     * Constructs a new instance.
038     */
039    public CompressedFileFileProvider() {
040    }
041
042    /**
043     * Create a FileSystem.
044     *
045     * @param name a file name.
046     * @param file a file object.
047     * @param fileSystemOptions the file system options.
048     * @return a FileSystem.
049     * @throws FileSystemException if a file system error occurs.
050     */
051    protected abstract FileSystem createFileSystem(FileName name, FileObject file, FileSystemOptions fileSystemOptions) throws FileSystemException;
052
053    /**
054     * Creates a layered file system. This method is called if the file system is not cached.
055     *
056     * @param scheme The URI scheme.
057     * @param file The file to create the file system on top of.
058     * @return The file system.
059     */
060    @Override
061    protected FileSystem doCreateFileSystem(final String scheme, final FileObject file,
062            final FileSystemOptions fileSystemOptions) throws FileSystemException {
063        final FileName name = new LayeredFileName(scheme, file.getName(), FileName.ROOT_PATH, FileType.FOLDER);
064        return createFileSystem(name, file, fileSystemOptions);
065    }
066
067    @Override
068    public abstract Collection<Capability> getCapabilities();
069}