    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 tries to
    027 * construct a file path from the locator's base path and file name.
    028 * </p>
    029 * <p>
    030 * This strategies ignores the URL stored in the passed in {@link FileLocator}.
    031 * It generates a path by concatenating the base path (if present) and the file
    032 * name. If the resulting path points to a valid file, the corresponding URL is
    033 * returned.
    034 * </p>
    035 *
    036 * @since 2.0
    037 */
    038public class BasePathLocationStrategy implements FileLocationStrategy
    039{
    040    /**
    041     * {@inheritDoc} This implementation uses utility methods from
    042     * {@code FileLocatorUtils} to generate a {@code File} from the locator's
    043     * base path and file name. If this {@code File} exists, its URL is
    044     * returned.
    045     */
    046    @Override
    047    public URL locate(final FileSystem fileSystem, final FileLocator locator)
    048    {
    049        if (StringUtils.isNotEmpty(locator.getFileName()))
    050        {
    051            final File file =
    052                    FileLocatorUtils.constructFile(locator.getBasePath(),
    053                            locator.getFileName());
    054            if (file.isFile())
    055            {
    056                return FileLocatorUtils.convertFileToURL(file);
    057            }
    058        }
    059
    060        return null;
    061    }
    062}