    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 *      https://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     * Constructs 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     * Constructs 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 instance 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, final String... skip) {
    068        super(pathCounter);
    069        final String[] temp = skip != null ? skip.clone() : EMPTY_STRING_ARRAY;
    070        Arrays.sort(temp);
    071        this.skip = temp;
    072        this.overrideReadOnly = StandardDeleteOption.overrideReadOnly(deleteOption);
    073    }
    074
    075    /**
    076     * Constructs a new instance that deletes files except for the files and directories explicitly given.
    077     *
    078     * @param pathCounter How to count visits.
    079     * @param skip The files to skip deleting.
    080     */
    081    public CleaningPathVisitor(final PathCounters pathCounter, final String... skip) {
    082        this(pathCounter, PathUtils.EMPTY_DELETE_OPTION_ARRAY, skip);
    083    }
    084
    085    /**
    086     * Returns true to process the given path, false if not.
    087     *
    088     * @param path the path to test.
    089     * @return true to process the given path, false if not.
    090     */
    091    private boolean accept(final Path path) {
    092        return Arrays.binarySearch(skip, PathUtils.getFileNameString(path)) < 0;
    093    }
    094
    095    @Override
    096    public boolean equals(final Object obj) {
    097        if (this == obj) {
    098            return true;
    099        }
    100        if (!super.equals(obj)) {
    101            return false;
    102        }
    103        if (getClass() != obj.getClass()) {
    104            return false;
    105        }
    106        final CleaningPathVisitor other = (CleaningPathVisitor) obj;
    107        return overrideReadOnly == other.overrideReadOnly && Arrays.equals(skip, other.skip);
    108    }
    109
    110    @Override
    111    public int hashCode() {
    112        final int prime = 31;
    113        int result = super.hashCode();
    114        result = prime * result + Arrays.hashCode(skip);
    115        result = prime * result + Objects.hash(overrideReadOnly);
    116        return result;
    117    }
    118
    119    @Override
    120    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attributes) throws IOException {
    121        super.preVisitDirectory(dir, attributes);
    122        return accept(dir) ? FileVisitResult.CONTINUE : FileVisitResult.SKIP_SUBTREE;
    123    }
    124
    125    @Override
    126    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
    127        // Files.deleteIfExists() never follows links, so use LinkOption.NOFOLLOW_LINKS in other calls to Files.
    128        if (accept(file) && Files.exists(file, LinkOption.NOFOLLOW_LINKS)) {
    129            if (overrideReadOnly) {
    130                PathUtils.setReadOnly(file, false, LinkOption.NOFOLLOW_LINKS);
    131            }
    132            Files.deleteIfExists(file);
    133        }
    134        updateFileCounters(file, attributes);
    135        return FileVisitResult.CONTINUE;
    136    }
    137}