src/java/org/apache/commons/vfs/provider/tar/TarFileProvider.java

/*
 * Copyright 2002-2005 The Apache Software Foundation.
 * 
 * Licensed 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.vfs.provider.tar;

import org.apache.commons.vfs.Capability;
import org.apache.commons.vfs.FileName;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystem;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.FileSystemOptions;
import org.apache.commons.vfs.provider.AbstractLayeredFileProvider;
import org.apache.commons.vfs.provider.FileProvider;
import org.apache.commons.vfs.provider.LayeredFileName;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;

/**
 * A file system provider for Tar files.  Provides read-only file systems.
 */
public class TarFileProvider
    extends AbstractLayeredFileProvider
    implements FileProvider
{
    protected final static Collection capabilities = Collections.unmodifiableCollection(Arrays.asList(new Capability[]
    {
        Capability.GET_LAST_MODIFIED,
        Capability.GET_TYPE,
        Capability.LIST_CHILDREN,
        Capability.READ_CONTENT,
        Capability.URI,
        Capability.VIRTUAL
    }));

    public TarFileProvider()
    {
        super();
    }

    /**
     * Creates a layered file system.  This method is called if the file system
     * is not cached.
     *
     * @param scheme The URI scheme.
     * @param file   The file to create the file system on top of.
     * @return The file system.
     */
    protected FileSystem doCreateFileSystem(final String scheme,
                                            final FileObject file,
                                            final FileSystemOptions fileSystemOptions)
        throws FileSystemException
    {
        final FileName rootName =
            new LayeredFileName(scheme, file.getName(), FileName.ROOT_PATH);
        return new TarFileSystem(rootName, file, fileSystemOptions);
    }

    public Collection getCapabilities()
    {
        return capabilities;
    }
}