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}