    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.LinkOption;
    024import java.nio.file.Path;
    025import java.nio.file.attribute.BasicFileAttributes;
    026import java.util.Arrays;
    027import java.util.Objects;
    028
    029import org.apache.commons.io.file.Counters.PathCounters;
    030
    031/**
    032 * Deletes files but not directories as a visit proceeds.
    033 *
    034 * @since 2.7
    035 */
    036public class CleaningPathVisitor extends CountingPathVisitor {
    037
    038    /**
    039     * Creates a new instance configured with a BigInteger {@link PathCounters}.
    040     *
    041     * @return a new instance configured with a BigInteger {@link PathCounters}.
    042     */
    043    public static CountingPathVisitor withBigIntegerCounters() {
    044        return new CleaningPathVisitor(Counters.bigIntegerPathCounters());
    045    }
    046
    047    /**
    048     * Creates a new instance configured with a long {@link PathCounters}.
    049     *
    050     * @return a new instance configured with a long {@link PathCounters}.
    051     */
    052    public static CountingPathVisitor withLongCounters() {
    053        return new CleaningPathVisitor(Counters.longPathCounters());
    054    }
    055
    056    private final String[] skip;
    057    private final boolean overrideReadOnly;
    058
    059    /**
    060     * Constructs a new visitor that deletes files except for the files and directories explicitly given.
    061     *
    062     * @param pathCounter How to count visits.
    063     * @param deleteOption How deletion is handled.
    064     * @param skip The files to skip deleting.
    065     * @since 2.8.0
    066     */
    067    public CleaningPathVisitor(final PathCounters pathCounter, final DeleteOption[] deleteOption,
    068        final String... skip) {
    069        super(pathCounter);
    070        final String[] temp = skip != null ? skip.clone() : EMPTY_STRING_ARRAY;
    071        Arrays.sort(temp);
    072        this.skip = temp;
    073        this.overrideReadOnly = StandardDeleteOption.overrideReadOnly(deleteOption);
    074    }
    075
    076    /**
    077     * Constructs a new visitor that deletes files except for the files and directories explicitly given.
    078     *
    079     * @param pathCounter How to count visits.
    080     * @param skip The files to skip deleting.
    081     */
    082    public CleaningPathVisitor(final PathCounters pathCounter, final String... skip) {
    083        this(pathCounter, PathUtils.EMPTY_DELETE_OPTION_ARRAY, skip);
    084    }
    085
    086    /**
    087     * Returns true to process the given path, false if not.
    088     *
    089     * @param path the path to test.
    090     * @return true to process the given path, false if not.
    091     */
    092    private boolean accept(final Path path) {
    093        return Arrays.binarySearch(skip, Objects.toString(path.getFileName(), null)) < 0;
    094    }
    095
    096    @Override
    097    public boolean equals(final Object obj) {
    098        if (this == obj) {
    099            return true;
    100        }
    101        if (!super.equals(obj)) {
    102            return false;
    103        }
    104        if (getClass() != obj.getClass()) {
    105            return false;
    106        }
    107        final CleaningPathVisitor other = (CleaningPathVisitor) obj;
    108        return overrideReadOnly == other.overrideReadOnly && Arrays.equals(skip, other.skip);
    109    }
    110
    111    @Override
    112    public int hashCode() {
    113        final int prime = 31;
    114        int result = super.hashCode();
    115        result = prime * result + Arrays.hashCode(skip);
    116        result = prime * result + Objects.hash(overrideReadOnly);
    117        return result;
    118    }
    119
    120    @Override
    121    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attributes) throws IOException {
    122        super.preVisitDirectory(dir, attributes);
    123        return accept(dir) ? FileVisitResult.CONTINUE : FileVisitResult.SKIP_SUBTREE;
    124    }
    125
    126    @Override
    127    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
    128        // Files.deleteIfExists() never follows links, so use LinkOption.NOFOLLOW_LINKS in other calls to Files.
    129        if (accept(file) && Files.exists(file, LinkOption.NOFOLLOW_LINKS)) {
    130            if (overrideReadOnly) {
    131                PathUtils.setReadOnly(file, false, LinkOption.NOFOLLOW_LINKS);
    132            }
    133            Files.deleteIfExists(file);
    134        }
    135        updateFileCounters(file, attributes);
    136        return FileVisitResult.CONTINUE;
    137    }
    138}