    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 */
    018
    019package org.apache.commons.compress.archivers.zip;
    020
    021import org.apache.commons.compress.archivers.ArchiveStreamFactory;
    022import org.apache.commons.compress.utils.FileNameUtils;
    023import org.apache.commons.compress.utils.MultiReadOnlySeekableByteChannel;
    024
    025import java.io.File;
    026import java.io.IOException;
    027import java.io.Serializable;
    028import java.nio.ByteBuffer;
    029import java.nio.channels.SeekableByteChannel;
    030import java.nio.file.Files;
    031import java.nio.file.StandardOpenOption;
    032import java.util.ArrayList;
    033import java.util.Arrays;
    034import java.util.Comparator;
    035import java.util.List;
    036import java.util.Objects;
    037import java.util.regex.Pattern;
    038
    039/**
    040 * {@link MultiReadOnlySeekableByteChannel} that knows what a split ZIP archive should look like.
    041 *
    042 * <p>If you want to read a split archive using {@link ZipFile} then create an instance of this class from the parts of
    043 * the archive.</p>
    044 *
    045 * @since 1.20
    046 */
    047public class ZipSplitReadOnlySeekableByteChannel extends MultiReadOnlySeekableByteChannel {
    048    private static final int ZIP_SPLIT_SIGNATURE_LENGTH = 4;
    049    private final ByteBuffer zipSplitSignatureByteBuffer =
    050        ByteBuffer.allocate(ZIP_SPLIT_SIGNATURE_LENGTH);
    051
    052    /**
    053     * Concatenates the given channels.
    054     *
    055     * <p>The channels should be add in ascending order, e.g. z01,
    056     * z02, ... z99, zip please note that the .zip file is the last
    057     * segment and should be added as the last one in the channels</p>
    058     *
    059     * @param channels the channels to concatenate
    060     * @throws NullPointerException if channels is null
    061     * @throws IOException if the first channel doesn't seem to hold
    062     * the beginning of a split archive
    063     */
    064    public ZipSplitReadOnlySeekableByteChannel(final List<SeekableByteChannel> channels)
    065        throws IOException {
    066        super(channels);
    067
    068        // the first split zip segment should begin with zip split signature
    069        assertSplitSignature(channels);
    070    }
    071
    072    /**
    073     * Based on the zip specification:
    074     *
    075     * <p>
    076     * 8.5.3 Spanned/Split archives created using PKZIP for Windows
    077     * (V2.50 or greater), PKZIP Command Line (V2.50 or greater),
    078     * or PKZIP Explorer will include a special spanning
    079     * signature as the first 4 bytes of the first segment of
    080     * the archive.  This signature (0x08074b50) will be
    081     * followed immediately by the local header signature for
    082     * the first file in the archive.
    083     *
    084     * <p>
    085     * the first 4 bytes of the first zip split segment should be the zip split signature(0x08074B50)
    086     *
    087     * @param channels channels to be validated
    088     * @throws IOException
    089     */
    090    private void assertSplitSignature(final List<SeekableByteChannel> channels)
    091        throws IOException {
    092        final SeekableByteChannel channel = channels.get(0);
    093        // the zip split file signature is at the beginning of the first split segment
    094        channel.position(0L);
    095
    096        zipSplitSignatureByteBuffer.rewind();
    097        channel.read(zipSplitSignatureByteBuffer);
    098        final ZipLong signature = new ZipLong(zipSplitSignatureByteBuffer.array());
    099        if (!signature.equals(ZipLong.DD_SIG)) {
    100            channel.position(0L);
    101            throw new IOException("The first zip split segment does not begin with split zip file signature");
    102        }
    103
    104        channel.position(0L);
    105    }
    106
    107    /**
    108     * Concatenates the given channels.
    109     *
    110     * @param channels the channels to concatenate, note that the LAST CHANNEL of channels should be the LAST SEGMENT(.zip)
    111     *                 and theses channels should be added in correct order (e.g. .z01, .z02... .z99, .zip)
    112     * @return SeekableByteChannel that concatenates all provided channels
    113     * @throws NullPointerException if channels is null
    114     * @throws IOException if reading channels fails
    115     */
    116    public static SeekableByteChannel forOrderedSeekableByteChannels(final SeekableByteChannel... channels) throws IOException {
    117        if (Objects.requireNonNull(channels, "channels must not be null").length == 1) {
    118            return channels[0];
    119        }
    120        return new ZipSplitReadOnlySeekableByteChannel(Arrays.asList(channels));
    121    }
    122
    123    /**
    124     * Concatenates the given channels.
    125     *
    126     * @param lastSegmentChannel channel of the last segment of split zip segments, its extension should be .zip
    127     * @param channels           the channels to concatenate except for the last segment,
    128     *                           note theses channels should be added in correct order (e.g. .z01, .z02... .z99)
    129     * @return SeekableByteChannel that concatenates all provided channels
    130     * @throws NullPointerException if lastSegmentChannel or channels is null
    131     * @throws IOException if the first channel doesn't seem to hold
    132     * the beginning of a split archive
    133     */
    134    public static SeekableByteChannel forOrderedSeekableByteChannels(final SeekableByteChannel lastSegmentChannel,
    135        final Iterable<SeekableByteChannel> channels) throws IOException {
    136        Objects.requireNonNull(channels, "channels");
    137        Objects.requireNonNull(lastSegmentChannel, "lastSegmentChannel");
    138
    139        final List<SeekableByteChannel> channelsList = new ArrayList<>();
    140        for (final SeekableByteChannel channel : channels) {
    141            channelsList.add(channel);
    142        }
    143        channelsList.add(lastSegmentChannel);
    144
    145        return forOrderedSeekableByteChannels(channelsList.toArray(new SeekableByteChannel[0]));
    146    }
    147
    148    /**
    149     * Concatenates zip split files from the last segment(the extension SHOULD be .zip)
    150     *
    151     * @param lastSegmentFile the last segment of zip split files, note that the extension SHOULD be .zip
    152     * @return SeekableByteChannel that concatenates all zip split files
    153     * @throws IllegalArgumentException if the lastSegmentFile's extension is NOT .zip
    154     * @throws IOException if the first channel doesn't seem to hold
    155     * the beginning of a split archive
    156     */
    157    public static SeekableByteChannel buildFromLastSplitSegment(final File lastSegmentFile) throws IOException {
    158        final String extension = FileNameUtils.getExtension(lastSegmentFile.getCanonicalPath());
    159        if (!extension.equalsIgnoreCase(ArchiveStreamFactory.ZIP)) {
    160            throw new IllegalArgumentException("The extension of last zip split segment should be .zip");
    161        }
    162
    163        final File parent = lastSegmentFile.getParentFile();
    164        final String fileBaseName = FileNameUtils.getBaseName(lastSegmentFile.getCanonicalPath());
    165        final ArrayList<File> splitZipSegments = new ArrayList<>();
    166
    167        // zip split segments should be like z01,z02....z(n-1) based on the zip specification
    168        final Pattern pattern = Pattern.compile(Pattern.quote(fileBaseName) + ".[zZ][0-9]+");
    169        final File[] children = parent.listFiles();
    170        if (children != null) {
    171            for (final File file : children) {
    172                if (!pattern.matcher(file.getName()).matches()) {
    173                    continue;
    174                }
    175
    176                splitZipSegments.add(file);
    177            }
    178        }
    179
    180        splitZipSegments.sort(new ZipSplitSegmentComparator());
    181        return forFiles(lastSegmentFile, splitZipSegments);
    182    }
    183
    184    /**
    185     * Concatenates the given files.
    186     *
    187     * @param files the files to concatenate, note that the LAST FILE of files should be the LAST SEGMENT(.zip)
    188     *              and theses files should be added in correct order (e.g. .z01, .z02... .z99, .zip)
    189     * @return SeekableByteChannel that concatenates all provided files
    190     * @throws NullPointerException if files is null
    191     * @throws IOException          if opening a channel for one of the files fails
    192     * @throws IOException if the first channel doesn't seem to hold
    193     * the beginning of a split archive
    194     */
    195    public static SeekableByteChannel forFiles(final File... files) throws IOException {
    196        final List<SeekableByteChannel> channels = new ArrayList<>();
    197        for (final File f : Objects.requireNonNull(files, "files must not be null")) {
    198            channels.add(Files.newByteChannel(f.toPath(), StandardOpenOption.READ));
    199        }
    200        if (channels.size() == 1) {
    201            return channels.get(0);
    202        }
    203        return new ZipSplitReadOnlySeekableByteChannel(channels);
    204    }
    205
    206    /**
    207     * Concatenates the given files.
    208     *
    209     * @param lastSegmentFile the last segment of split zip segments, its extension should be .zip
    210     * @param files           the files to concatenate except for the last segment,
    211     *                        note theses files should be added in correct order (e.g. .z01, .z02... .z99)
    212     * @return SeekableByteChannel that concatenates all provided files
    213     * @throws IOException if the first channel doesn't seem to hold
    214     * the beginning of a split archive
    215     * @throws NullPointerException if files or lastSegmentFile is null
    216     */
    217    public static SeekableByteChannel forFiles(final File lastSegmentFile, final Iterable<File> files) throws IOException {
    218        Objects.requireNonNull(files, "files");
    219        Objects.requireNonNull(lastSegmentFile, "lastSegmentFile");
    220
    221        final List<File> filesList = new ArrayList<>();
    222        for (final File f : files) {
    223            filesList.add(f);
    224        }
    225        filesList.add(lastSegmentFile);
    226
    227        return forFiles(filesList.toArray(new File[0]));
    228    }
    229
    230    private static class ZipSplitSegmentComparator implements Comparator<File>, Serializable {
    231        private static final long serialVersionUID = 20200123L;
    232        @Override
    233        public int compare(final File file1, final File file2) {
    234            final String extension1 = FileNameUtils.getExtension(file1.getPath());
    235            final String extension2 = FileNameUtils.getExtension(file2.getPath());
    236
    237            if (!extension1.startsWith("z")) {
    238                return -1;
    239            }
    240
    241            if (!extension2.startsWith("z")) {
    242                return 1;
    243            }
    244
    245            final Integer splitSegmentNumber1 = Integer.parseInt(extension1.substring(1));
    246            final Integer splitSegmentNumber2 = Integer.parseInt(extension2.substring(1));
    247
    248            return splitSegmentNumber1.compareTo(splitSegmentNumber2);
    249        }
    250    }
    251}