    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.math.BigInteger;
    022import java.nio.file.FileVisitResult;
    023import java.nio.file.Files;
    024import java.nio.file.Path;
    025import java.nio.file.attribute.BasicFileAttributes;
    026import java.util.Objects;
    027
    028import org.apache.commons.io.file.Counters.PathCounters;
    029import org.apache.commons.io.filefilter.IOFileFilter;
    030import org.apache.commons.io.filefilter.SymbolicLinkFileFilter;
    031import org.apache.commons.io.filefilter.TrueFileFilter;
    032import org.apache.commons.io.function.IOBiFunction;
    033
    034/**
    035 * Counts files, directories, and sizes, as a visit proceeds.
    036 *
    037 * @since 2.7
    038 */
    039public class CountingPathVisitor extends SimplePathVisitor {
    040
    041    static final String[] EMPTY_STRING_ARRAY = {};
    042
    043    static IOFileFilter defaultDirFilter() {
    044        return TrueFileFilter.INSTANCE;
    045    }
    046
    047    static IOFileFilter defaultFileFilter() {
    048        return new SymbolicLinkFileFilter(FileVisitResult.TERMINATE, FileVisitResult.CONTINUE);
    049    }
    050
    051    /**
    052     * Constructs a new instance configured with a {@link BigInteger} {@link PathCounters}.
    053     *
    054     * @return a new instance configured with a {@link BigInteger} {@link PathCounters}.
    055     */
    056    public static CountingPathVisitor withBigIntegerCounters() {
    057        return new CountingPathVisitor(Counters.bigIntegerPathCounters());
    058    }
    059
    060    /**
    061     * Constructs a new instance configured with a {@code long} {@link PathCounters}.
    062     *
    063     * @return a new instance configured with a {@code long} {@link PathCounters}.
    064     */
    065    public static CountingPathVisitor withLongCounters() {
    066        return new CountingPathVisitor(Counters.longPathCounters());
    067    }
    068
    069    private final PathCounters pathCounters;
    070    private final PathFilter fileFilter;
    071    private final PathFilter dirFilter;
    072
    073    /**
    074     * Constructs a new instance.
    075     *
    076     * @param pathCounter How to count path visits.
    077     */
    078    public CountingPathVisitor(final PathCounters pathCounter) {
    079        this(pathCounter, defaultFileFilter(), defaultDirFilter());
    080    }
    081
    082    /**
    083     * Constructs a new instance.
    084     *
    085     * @param pathCounter How to count path visits.
    086     * @param fileFilter Filters which files to count.
    087     * @param dirFilter Filters which directories to count.
    088     * @since 2.9.0
    089     */
    090    public CountingPathVisitor(final PathCounters pathCounter, final PathFilter fileFilter, final PathFilter dirFilter) {
    091        this.pathCounters = Objects.requireNonNull(pathCounter, "pathCounter");
    092        this.fileFilter = Objects.requireNonNull(fileFilter, "fileFilter");
    093        this.dirFilter = Objects.requireNonNull(dirFilter, "dirFilter");
    094    }
    095
    096    /**
    097     * Constructs a new instance.
    098     *
    099     * @param pathCounter How to count path visits.
    100     * @param fileFilter Filters which files to count.
    101     * @param dirFilter Filters which directories to count.
    102     * @param visitFileFailed Called on {@link #visitFileFailed(Path, IOException)}.
    103     * @since 2.12.0
    104     */
    105    public CountingPathVisitor(final PathCounters pathCounter, final PathFilter fileFilter, final PathFilter dirFilter,
    106        final IOBiFunction<Path, IOException, FileVisitResult> visitFileFailed) {
    107        super(visitFileFailed);
    108        this.pathCounters = Objects.requireNonNull(pathCounter, "pathCounter");
    109        this.fileFilter = Objects.requireNonNull(fileFilter, "fileFilter");
    110        this.dirFilter = Objects.requireNonNull(dirFilter, "dirFilter");
    111    }
    112
    113    @Override
    114    public boolean equals(final Object obj) {
    115        if (this == obj) {
    116            return true;
    117        }
    118        if (!(obj instanceof CountingPathVisitor)) {
    119            return false;
    120        }
    121        final CountingPathVisitor other = (CountingPathVisitor) obj;
    122        return Objects.equals(pathCounters, other.pathCounters);
    123    }
    124
    125    /**
    126     * Gets the visitation counts.
    127     *
    128     * @return the visitation counts.
    129     */
    130    public PathCounters getPathCounters() {
    131        return pathCounters;
    132    }
    133
    134    @Override
    135    public int hashCode() {
    136        return Objects.hash(pathCounters);
    137    }
    138
    139    @Override
    140    public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
    141        updateDirCounter(dir, exc);
    142        return FileVisitResult.CONTINUE;
    143    }
    144
    145    @Override
    146    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attributes) throws IOException {
    147        final FileVisitResult accept = dirFilter.accept(dir, attributes);
    148        return accept != FileVisitResult.CONTINUE ? FileVisitResult.SKIP_SUBTREE : FileVisitResult.CONTINUE;
    149    }
    150
    151    @Override
    152    public String toString() {
    153        return pathCounters.toString();
    154    }
    155
    156    /**
    157     * Updates the counter for visiting the given directory.
    158     *
    159     * @param dir the visited directory.
    160     * @param exc Encountered exception.
    161     * @since 2.9.0
    162     */
    163    protected void updateDirCounter(final Path dir, final IOException exc) {
    164        pathCounters.getDirectoryCounter().increment();
    165    }
    166
    167    /**
    168     * Updates the counters for visiting the given file.
    169     *
    170     * @param file the visited file.
    171     * @param attributes the visited file attributes.
    172     */
    173    protected void updateFileCounters(final Path file, final BasicFileAttributes attributes) {
    174        pathCounters.getFileCounter().increment();
    175        pathCounters.getByteCounter().add(attributes.size());
    176    }
    177
    178    @Override
    179    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
    180        // Note: A file can be a symbolic link to a directory.
    181        if (Files.exists(file) && fileFilter.accept(file, attributes) == FileVisitResult.CONTINUE) {
    182            updateFileCounters(file, attributes);
    183        }
    184        return FileVisitResult.CONTINUE;
    185    }
    186
    187}