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 and directories as a visit proceeds.
033 *
034 * @since 2.7
035 */
036public class DeletingPathVisitor extends CountingPathVisitor {
037
038
039    /**
040     * Creates a new instance configured with a BigInteger {@link PathCounters}.
041     *
042     * @return a new instance configured with a BigInteger {@link PathCounters}.
043     */
044    public static DeletingPathVisitor withBigIntegerCounters() {
045        return new DeletingPathVisitor(Counters.bigIntegerPathCounters());
046    }
047
048    /**
049     * Creates a new instance configured with a long {@link PathCounters}.
050     *
051     * @return a new instance configured with a long {@link PathCounters}.
052     */
053    public static DeletingPathVisitor withLongCounters() {
054        return new DeletingPathVisitor(Counters.longPathCounters());
055    }
056
057    private final String[] skip;
058    private final boolean overrideReadOnly;
059
060    /**
061     * Constructs a new visitor that deletes files except for the files and directories explicitly given.
062     *
063     * @param pathCounter How to count visits.
064     * @param deleteOption options indicating how deletion is handled.
065     * @param skip The files to skip deleting.
066     * @since 2.8.0
067     */
068    public DeletingPathVisitor(final PathCounters pathCounter, final DeleteOption[] deleteOption, 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     *
081     * @param skip The files to skip deleting.
082     */
083    public DeletingPathVisitor(final PathCounters pathCounter, final String... skip) {
084        this(pathCounter, PathUtils.EMPTY_DELETE_OPTION_ARRAY, skip);
085    }
086
087    /**
088     * Returns true to process the given path, false if not.
089     *
090     * @param path the path to test.
091     * @return true to process the given path, false if not.
092     */
093    private boolean accept(final Path path) {
094        return Arrays.binarySearch(skip, Objects.toString(path.getFileName(), null)) < 0;
095    }
096
097    @Override
098    public boolean equals(final Object obj) {
099        if (this == obj) {
100            return true;
101        }
102        if (!super.equals(obj)) {
103            return false;
104        }
105        if (getClass() != obj.getClass()) {
106            return false;
107        }
108        final DeletingPathVisitor other = (DeletingPathVisitor) obj;
109        return overrideReadOnly == other.overrideReadOnly && Arrays.equals(skip, other.skip);
110    }
111
112    @Override
113    public int hashCode() {
114        final int prime = 31;
115        int result = super.hashCode();
116        result = prime * result + Arrays.hashCode(skip);
117        result = prime * result + Objects.hash(overrideReadOnly);
118        return result;
119    }
120
121    @Override
122    public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
123        if (PathUtils.isEmptyDirectory(dir)) {
124            Files.deleteIfExists(dir);
125        }
126        return super.postVisitDirectory(dir, exc);
127    }
128
129    @Override
130    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attrs) throws IOException {
131        super.preVisitDirectory(dir, attrs);
132        return accept(dir) ? FileVisitResult.CONTINUE : FileVisitResult.SKIP_SUBTREE;
133    }
134
135    @Override
136    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs) throws IOException {
137        // Files.deleteIfExists() never follows links, so use LinkOption.NOFOLLOW_LINKS in other calls to Files.
138        if (accept(file) && Files.exists(file, LinkOption.NOFOLLOW_LINKS)) {
139            if (overrideReadOnly) {
140                PathUtils.setReadOnly(file, false, LinkOption.NOFOLLOW_LINKS);
141            }
142            Files.deleteIfExists(file);
143        }
144        updateFileCounters(file, attrs);
145        return FileVisitResult.CONTINUE;
146    }
147}