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
027 * whether the provided file name is already an absolute file name.
028 * </p>
029 * <p>
030 * This strategy ignores the URL and the base path stored in the passed in
031 * {@link FileLocator}. It is only triggered by absolute names in the locator's
032 * {@code fileName} component.
033 * </p>
034 *
035 * @version $Id: AbsoluteNameLocationStrategy.java 1624601 2014-09-12 18:04:36Z oheger $
036 * @since 2.0
037 */
038public class AbsoluteNameLocationStrategy implements FileLocationStrategy
039{
040    /**
041     * {@inheritDoc} This implementation constructs a {@code File} object from
042     * the locator's file name (if defined). If this results in an absolute file
043     * name pointing to an existing file, the corresponding URL is returned.
044     */
045    @Override
046    public URL locate(FileSystem fileSystem, FileLocator locator)
047    {
048        if (StringUtils.isNotEmpty(locator.getFileName()))
049        {
050            File file = new File(locator.getFileName());
051            if (file.isAbsolute() && file.exists())
052            {
053                return FileLocatorUtils.convertFileToURL(file);
054            }
055        }
056
057        return null;
058    }
059}