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.jar;
018
019import java.util.ArrayList;
020import java.util.Arrays;
021import java.util.Collection;
022import java.util.Collections;
023
024import org.apache.commons.vfs2.Capability;
025import org.apache.commons.vfs2.FileName;
026import org.apache.commons.vfs2.FileObject;
027import org.apache.commons.vfs2.FileSystem;
028import org.apache.commons.vfs2.FileSystemException;
029import org.apache.commons.vfs2.FileSystemOptions;
030import org.apache.commons.vfs2.FileType;
031import org.apache.commons.vfs2.provider.AbstractFileName;
032import org.apache.commons.vfs2.provider.LayeredFileName;
033import org.apache.commons.vfs2.provider.zip.ZipFileProvider;
034
035/**
036 * A file system provider for Jar files.  Provides read-only file
037 * systems.  This provides access to Jar specific features like Signing and
038 * Manifest Attributes.
039 */
040public class JarFileProvider extends ZipFileProvider
041{
042    static final Collection<Capability> capabilities;
043
044    static
045    {
046        final Collection<Capability> combined = new ArrayList<Capability>();
047        combined.addAll(ZipFileProvider.capabilities);
048        combined.addAll(Arrays.asList(new Capability[]
049            {
050                Capability.ATTRIBUTES,
051                Capability.FS_ATTRIBUTES,
052                Capability.SIGNING,
053                Capability.MANIFEST_ATTRIBUTES,
054                Capability.VIRTUAL
055            }));
056        capabilities = Collections.unmodifiableCollection(combined);
057    }
058
059    public JarFileProvider()
060    {
061        super();
062    }
063
064    /**
065     * Creates a layered file system.  This method is called if the file system
066     * is not cached.
067     *
068     * @param scheme The URI scheme.
069     * @param file   The file to create the file system on top of.
070     * @return The file system.
071     */
072    @Override
073    protected FileSystem doCreateFileSystem(final String scheme,
074                                            final FileObject file,
075                                            final FileSystemOptions fileSystemOptions)
076        throws FileSystemException
077    {
078        final AbstractFileName name =
079            new LayeredFileName(scheme, file.getName(), FileName.ROOT_PATH, FileType.FOLDER);
080        return new JarFileSystem(name, file, fileSystemOptions);
081    }
082
083    @Override
084    public Collection<Capability> getCapabilities()
085    {
086        return capabilities;
087    }
088}