commons-vfs2/src/main/java/org/apache/commons/vfs2/provider/CompositeFileProvider.java

/*
 * 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 java.util.Arrays;

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() {
    }

    /**
     * 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(getContext().getFileSystemManager().getSchemes(), uri, buf);
        Arrays.stream(getSchemes()).forEach(scheme -> buf.insert(0, scheme + ":"));

        return getContext().getFileSystemManager().resolveFile(buf.toString(), fileSystemOptions);
    }
}