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.configuration2.io;
018
019import java.io.File;
020import java.net.URL;
021
022import org.apache.commons.lang3.StringUtils;
023
024/**
025 * <p>
026 * A specialized implementation of {@code FileLocationStrategy} which checks whether the provided file name is already
027 * an absolute file name.
028 * </p>
029 * <p>
030 * This strategy ignores the URL and the base path stored in the passed in {@link FileLocator}. It is only triggered by
031 * absolute names in the locator's {@code fileName} component.
032 * </p>
033 *
034 * @since 2.0
035 */
036public class AbsoluteNameLocationStrategy implements FileLocationStrategy {
037    /**
038     * {@inheritDoc} This implementation constructs a {@code File} object from the locator's file name (if defined). If this
039     * results in an absolute file name pointing to an existing file, the corresponding URL is returned.
040     */
041    @Override
042    public URL locate(final FileSystem fileSystem, final FileLocator locator) {
043        if (StringUtils.isNotEmpty(locator.getFileName())) {
044            final File file = new File(locator.getFileName());
045            if (file.isAbsolute() && file.exists()) {
046                return FileLocatorUtils.convertFileToURL(file);
047            }
048        }
049
050        return null;
051    }
052}