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