    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 and directories as a visit proceeds.
    032 *
    033 * @since 2.7
    034 */
    035public class DeletingPathVisitor extends CountingPathVisitor {
    036
    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 DeletingPathVisitor withBigIntegerCounters() {
    044        return new DeletingPathVisitor(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 DeletingPathVisitor withLongCounters() {
    053        return new DeletingPathVisitor(Counters.longPathCounters());
    054    }
    055
    056    private final String[] skip;
    057
    058    /**
    059     * Constructs a new visitor that deletes files except for the files and directories explicitly given.
    060     *
    061     * @param pathCounter How to count visits.
    062     *
    063     * @param skip The files to skip deleting.
    064     */
    065    public DeletingPathVisitor(final PathCounters pathCounter, final String... skip) {
    066        super(pathCounter);
    067        final String[] temp = skip != null ? skip.clone() : EMPTY_STRING_ARRAY;
    068        Arrays.sort(temp);
    069        this.skip = temp;
    070    }
    071
    072    /**
    073     * Returns true to process the given path, false if not.
    074     *
    075     * @param path the path to test.
    076     * @return true to process the given path, false if not.
    077     */
    078    private boolean accept(final Path path) {
    079        return Arrays.binarySearch(skip, Objects.toString(path.getFileName(), null)) < 0;
    080    }
    081
    082    @Override
    083    public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
    084        if (PathUtils.isEmptyDirectory(dir)) {
    085            Files.deleteIfExists(dir);
    086        }
    087        return super.postVisitDirectory(dir, exc);
    088    }
    089
    090    @Override
    091    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attrs) throws IOException {
    092        super.preVisitDirectory(dir, attrs);
    093        return accept(dir) ? FileVisitResult.CONTINUE : FileVisitResult.SKIP_SUBTREE;
    094    }
    095
    096    @Override
    097    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs) throws IOException {
    098        if (accept(file) && Files.exists(file)) {
    099            Files.deleteIfExists(file);
    100        }
    101        updateFileCounters(file, attrs);
    102        return FileVisitResult.CONTINUE;
    103    }
    104}