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.Objects;
026
027import org.apache.commons.io.file.Counters.PathCounters;
028
029/**
030 * Counts files, directories, and sizes, as a visit proceeds.
031 *
032 * @since 2.7
033 */
034public class CountingPathVisitor extends SimplePathVisitor {
035
036    static final String[] EMPTY_STRING_ARRAY = new String[0];
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 CountingPathVisitor(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 CountingPathVisitor(Counters.longPathCounters());
054    }
055
056    private final PathCounters pathCounters;
057
058    /**
059     * Constructs a new instance.
060     *
061     * @param pathCounter How to count path visits.
062     */
063    public CountingPathVisitor(final PathCounters pathCounter) {
064        super();
065        this.pathCounters = Objects.requireNonNull(pathCounter, "pathCounter");
066    }
067
068    @Override
069    public boolean equals(Object obj) {
070        if (this == obj) {
071            return true;
072        }
073        if (!(obj instanceof CountingPathVisitor)) {
074            return false;
075        }
076        CountingPathVisitor other = (CountingPathVisitor) obj;
077        return Objects.equals(pathCounters, other.pathCounters);
078    }
079
080    /**
081     * Gets the visitation counts.
082     *
083     * @return the visitation counts.
084     */
085    public PathCounters getPathCounters() {
086        return pathCounters;
087    }
088
089    @Override
090    public int hashCode() {
091        return Objects.hash(pathCounters);
092    }
093
094    @Override
095    public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
096        pathCounters.getDirectoryCounter().increment();
097        return FileVisitResult.CONTINUE;
098    }
099
100    @Override
101    public String toString() {
102        return pathCounters.toString();
103    }
104
105    /**
106     * Updates the counters for visiting the given file.
107     *
108     * @param file the visited file.
109     * @param attributes the visited file attributes.
110     */
111    protected void updateFileCounters(final Path file, final BasicFileAttributes attributes) {
112        pathCounters.getFileCounter().increment();
113        pathCounters.getByteCounter().add(attributes.size());
114    }
115
116    @Override
117    public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
118        if (Files.exists(file)) {
119            updateFileCounters(file, attributes);
120        }
121        return FileVisitResult.CONTINUE;
122    }
123
124}