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.vfs2;
018
019import java.util.Arrays;
020import java.util.Collection;
021import java.util.HashSet;
022import java.util.Set;
023
024/**
025 * A {@link FileSelector} that selects based on file extensions.
026 * <p>
027 * The extension comparison is case insensitive.
028 * </p>
029 * <p>
030 * The selector makes a copy of a given Collection or array. Changing the object passed in the constructors will not
031 * affect the selector.
032 * </p>
033 *
034 * @since 2.1
035 */
036public class FileExtensionSelector implements FileSelector {
037
038    /**
039     * The extensions to select.
040     */
041    private final Set<String> extensions = new HashSet<>();
042
043    /**
044     * Creates a new selector for the given extensions.
045     *
046     * @param extensions The extensions to be included by this selector.
047     */
048    public FileExtensionSelector(final Collection<String> extensions) {
049        if (extensions != null) {
050            this.extensions.addAll(extensions);
051        }
052    }
053
054    /**
055     * Creates a new selector for the given extensions.
056     *
057     * @param extensions The extensions to be included by this selector.
058     */
059    public FileExtensionSelector(final String... extensions) {
060        if (extensions != null) {
061            this.extensions.addAll(Arrays.asList(extensions));
062        }
063    }
064
065    /**
066     * Determines if a file or folder should be selected.
067     *
068     * @param fileInfo The file selection information.
069     * @return true if the file should be selected, false otherwise.
070     */
071    @Override
072    public boolean includeFile(final FileSelectInfo fileInfo) throws Exception {
073        return extensions.stream().anyMatch(extension -> fileInfo.getFile().getName().getExtension().equalsIgnoreCase(extension));
074    }
075
076    /**
077     * Determines whether a folder should be traversed.
078     *
079     * @param fileInfo The file selection information.
080     * @return true if descendants should be traversed, false otherwise.
081     */
082    @Override
083    public boolean traverseDescendents(final FileSelectInfo fileInfo) throws Exception {
084        return true;
085    }
086}