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    private static final int INITIAL_BUFSZ = 80;
028
029    public CompositeFileProvider() {
030        super();
031    }
032
033    /**
034     * The schemes known.
035     *
036     * @return Array of supported schemes.
037     */
038    protected abstract String[] getSchemes();
039
040    /**
041     * Locates a file object, by absolute URI.
042     *
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, final String uri, final FileSystemOptions fileSystemOptions)
051            throws FileSystemException {
052        final StringBuilder buf = new StringBuilder(INITIAL_BUFSZ);
053
054        UriParser.extractScheme(uri, buf);
055
056        final String[] schemes = getSchemes();
057        for (final String scheme : schemes) {
058            buf.insert(0, ":");
059            buf.insert(0, scheme);
060        }
061
062        final FileObject fo = getContext().getFileSystemManager().resolveFile(buf.toString(), fileSystemOptions);
063        return fo;
064    }
065}