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Apache Commons VFS is a Virtual File System library.

There is a newer version: 2.9.0

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.vfs2.provider;

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemOptions;

/**
 * Description.
 */
public abstract class CompositeFileProvider extends AbstractFileProvider {
    private static final int INITIAL_BUFSZ = 80;

    public CompositeFileProvider() {
        super();
    }

    /**
     * The schemes known.
     *
     * @return Array of supported schemes.
     */
    protected abstract String[] getSchemes();

    /**
     * Locates a file object, by absolute URI.
     *
     * @param baseFile The base FileObject.
     * @param uri The file to find.
     * @param fileSystemOptions The options for the FileSystem.
     * @return A FileObject for the located file.
     * @throws FileSystemException if an error occurs.
     */
    @Override
    public FileObject findFile(final FileObject baseFile, final String uri, final FileSystemOptions fileSystemOptions)
            throws FileSystemException {
        final StringBuilder buf = new StringBuilder(INITIAL_BUFSZ);

        UriParser.extractScheme(uri, buf);

        final String[] schemes = getSchemes();
        for (final String scheme : schemes) {
            buf.insert(0, ":");
            buf.insert(0, scheme);
        }

        final FileObject fo = getContext().getFileSystemManager().resolveFile(buf.toString(), fileSystemOptions);
        return fo;
    }
}