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;
018
019import org.apache.commons.vfs2.FileObject;
020import org.apache.commons.vfs2.FileSystemException;
021import org.apache.commons.vfs2.FileSystemOptions;
022
023/**
024 * Description.
025 */
026public abstract class CompositeFileProvider extends AbstractFileProvider
027{
028    private static final int INITIAL_BUFSZ = 80;
029
030    public CompositeFileProvider()
031    {
032        super();
033    }
034
035    /**
036     * The schemes known.
037     * @return Array of supported schemes.
038     */
039    protected abstract String[] getSchemes();
040
041    /**
042     * Locates a file object, by absolute URI.
043     * @param baseFile The base FileObject.
044     * @param uri The file to find.
045     * @param fileSystemOptions The options for the FileSystem.
046     * @return A FileObject for the located file.
047     * @throws FileSystemException if an error occurs.
048     */
049    @Override
050    public FileObject findFile(final FileObject baseFile,
051                               final String uri,
052                               final FileSystemOptions fileSystemOptions)
053        throws FileSystemException
054    {
055        final StringBuilder buf = new StringBuilder(INITIAL_BUFSZ);
056
057        UriParser.extractScheme(uri, buf);
058
059        final String[] schemes = getSchemes();
060        for (final String scheme : schemes)
061        {
062            buf.insert(0, ":");
063            buf.insert(0, scheme);
064        }
065
066        final FileObject fo = getContext().getFileSystemManager().resolveFile(buf.toString(), fileSystemOptions);
067        return fo;
068    }
069}