    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 */
    017
    018package org.apache.commons.io.file;
    019
    020import java.io.IOException;
    021import java.nio.file.FileVisitResult;
    022import java.nio.file.Files;
    023import java.nio.file.Path;
    024import java.nio.file.attribute.BasicFileAttributes;
    025import java.util.Arrays;
    026import java.util.Objects;
    027
    028import org.apache.commons.io.file.Counters.PathCounters;
    029
    030/**
    031 * Deletes files but not directories as a visit proceeds.
    032 *
    033 * @since 2.7
    034 */
    035public class CleaningPathVisitor extends CountingPathVisitor {
    036
    037    /**
    038     * Creates a new instance configured with a BigInteger {@link PathCounters}.
    039     *
    040     * @return a new instance configured with a BigInteger {@link PathCounters}.
    041     */
    042    public static CountingPathVisitor withBigIntegerCounters() {
    043        return new CleaningPathVisitor(Counters.bigIntegerPathCounters());
    044    }
    045
    046    /**
    047     * Creates a new instance configured with a long {@link PathCounters}.
    048     *
    049     * @return a new instance configured with a long {@link PathCounters}.
    050     */
    051    public static CountingPathVisitor withLongCounters() {
    052        return new CleaningPathVisitor(Counters.longPathCounters());
    053    }
    054
    055    private final String[] skip;
    056
    057    /**
    058     * Constructs a new visitor that deletes files except for the files and directories explicitly given.
    059     *
    060     * @param pathCounter How to count visits.
    061     * @param skip The files to skip deleting.
    062     */
    063    public CleaningPathVisitor(final PathCounters pathCounter, final String... skip) {
    064        super(pathCounter);
    065        final String[] temp = skip != null ? skip.clone() : EMPTY_STRING_ARRAY;
    066        Arrays.sort(temp);
    067        this.skip = temp;
    068    }
    069
    070    /**
    071     * Returns true to process the given path, false if not.
    072     *
    073     * @param path the path to test.
    074     * @return true to process the given path, false if not.
    075     */
    076    private boolean accept(final Path path) {
    077        return Arrays.binarySearch(skip, Objects.toString(path.getFileName(), null)) < 0;
    078    }
    079
    080    @Override
    081    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attributes) throws IOException {
    082        super.preVisitDirectory(dir, attributes);
    083        return accept(dir) ? FileVisitResult.CONTINUE : FileVisitResult.SKIP_SUBTREE;
    084    }
    085
    086    @Override
    087    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
    088        if (accept(file) && Files.exists(file)) {
    089            Files.deleteIfExists(file);
    090        }
    091        updateFileCounters(file, attributes);
    092        return FileVisitResult.CONTINUE;
    093    }
    094}