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Apache Commons Compress software defines an API for working with compression and archive formats. These include: bzip2, gzip, pack200, lzma, xz, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4, Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.

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/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.commons.compress.archivers.zip;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumSet;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.zip.Inflater;
import java.util.zip.ZipException;

import org.apache.commons.compress.archivers.EntryStreamOffsets;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.commons.compress.compressors.deflate64.Deflate64CompressorInputStream;
import org.apache.commons.compress.utils.BoundedArchiveInputStream;
import org.apache.commons.compress.utils.BoundedSeekableByteChannelInputStream;
import org.apache.commons.compress.utils.CountingInputStream;
import org.apache.commons.compress.utils.IOUtils;
import org.apache.commons.compress.utils.InputStreamStatistics;

/**
 * Replacement for {@code java.util.ZipFile}.
 *
 * 

This class adds support for file name encodings other than UTF-8 * (which is required to work on ZIP files created by native ZIP tools * and is able to skip a preamble like the one found in self * extracting archives. Furthermore it returns instances of * {@code org.apache.commons.compress.archivers.zip.ZipArchiveEntry} * instead of {@code java.util.zip.ZipEntry}.

* *

It doesn't extend {@code java.util.zip.ZipFile} as it would * have to reimplement all methods anyway. Like * {@code java.util.ZipFile}, it uses SeekableByteChannel under the * covers and supports compressed and uncompressed entries. As of * Apache Commons Compress 1.3 it also transparently supports Zip64 * extensions and thus individual entries and archives larger than 4 * GB or with more than 65536 entries.

* *

The method signatures mimic the ones of * {@code java.util.zip.ZipFile}, with a couple of exceptions: * *

    *
  • There is no getName method.
  • *
  • entries has been renamed to getEntries.
  • *
  • getEntries and getEntry return * {@code org.apache.commons.compress.archivers.zip.ZipArchiveEntry} * instances.
  • *
  • close is allowed to throw IOException.
  • *
*/ public class ZipFile implements Closeable { /** * Lock-free implementation of BoundedInputStream. The * implementation uses positioned reads on the underlying archive * file channel and therefore performs significantly faster in * concurrent environment. */ private class BoundedFileChannelInputStream extends BoundedArchiveInputStream { private final FileChannel archive; BoundedFileChannelInputStream(final long start, final long remaining) { super(start, remaining); archive = (FileChannel) ZipFile.this.archive; } @Override protected int read(final long pos, final ByteBuffer buf) throws IOException { final int read = archive.read(buf, pos); buf.flip(); return read; } } /** * Extends ZipArchiveEntry to store the offset within the archive. */ private static class Entry extends ZipArchiveEntry { Entry() { } @Override public boolean equals(final Object other) { if (super.equals(other)) { // super.equals would return false if other were not an Entry final Entry otherEntry = (Entry) other; return getLocalHeaderOffset() == otherEntry.getLocalHeaderOffset() && super.getDataOffset() == otherEntry.getDataOffset() && super.getDiskNumberStart() == otherEntry.getDiskNumberStart(); } return false; } @Override public int hashCode() { return 3 * super.hashCode() + (int) getLocalHeaderOffset()+(int)(getLocalHeaderOffset()>>32); } } private static final class NameAndComment { private final byte[] name; private final byte[] comment; private NameAndComment(final byte[] name, final byte[] comment) { this.name = name; this.comment = comment; } } private static class StoredStatisticsStream extends CountingInputStream implements InputStreamStatistics { StoredStatisticsStream(final InputStream in) { super(in); } @Override public long getCompressedCount() { return super.getBytesRead(); } @Override public long getUncompressedCount() { return getCompressedCount(); } } private static final int HASH_SIZE = 509; static final int NIBLET_MASK = 0x0f; static final int BYTE_SHIFT = 8; private static final int POS_0 = 0; private static final int POS_1 = 1; private static final int POS_2 = 2; private static final int POS_3 = 3; private static final byte[] ONE_ZERO_BYTE = new byte[1]; /** * Length of a "central directory" entry structure without file * name, extra fields or comment. */ private static final int CFH_LEN = /* version made by */ ZipConstants.SHORT /* version needed to extract */ + ZipConstants.SHORT /* general purpose bit flag */ + ZipConstants.SHORT /* compression method */ + ZipConstants.SHORT /* last mod file time */ + ZipConstants.SHORT /* last mod file date */ + ZipConstants.SHORT /* crc-32 */ + ZipConstants.WORD /* compressed size */ + ZipConstants.WORD /* uncompressed size */ + ZipConstants.WORD /* file name length */ + ZipConstants. SHORT /* extra field length */ + ZipConstants.SHORT /* file comment length */ + ZipConstants.SHORT /* disk number start */ + ZipConstants.SHORT /* internal file attributes */ + ZipConstants.SHORT /* external file attributes */ + ZipConstants.WORD /* relative offset of local header */ + ZipConstants.WORD; private static final long CFH_SIG = ZipLong.getValue(ZipArchiveOutputStream.CFH_SIG); /** * Length of the "End of central directory record" - which is * supposed to be the last structure of the archive - without file * comment. */ static final int MIN_EOCD_SIZE = /* end of central dir signature */ ZipConstants.WORD /* number of this disk */ + ZipConstants.SHORT /* number of the disk with the */ /* start of the central directory */ + ZipConstants.SHORT /* total number of entries in */ /* the central dir on this disk */ + ZipConstants.SHORT /* total number of entries in */ /* the central dir */ + ZipConstants.SHORT /* size of the central directory */ + ZipConstants.WORD /* offset of start of central */ /* directory with respect to */ /* the starting disk number */ + ZipConstants.WORD /* ZIP file comment length */ + ZipConstants.SHORT; /** * Maximum length of the "End of central directory record" with a * file comment. */ private static final int MAX_EOCD_SIZE = MIN_EOCD_SIZE /* maximum length of ZIP file comment */ + ZipConstants.ZIP64_MAGIC_SHORT; /** * Offset of the field that holds the location of the length of * the central directory inside the "End of central directory * record" relative to the start of the "End of central directory * record". */ private static final int CFD_LENGTH_OFFSET = /* end of central dir signature */ ZipConstants.WORD /* number of this disk */ + ZipConstants.SHORT /* number of the disk with the */ /* start of the central directory */ + ZipConstants.SHORT /* total number of entries in */ /* the central dir on this disk */ + ZipConstants.SHORT /* total number of entries in */ /* the central dir */ + ZipConstants.SHORT; /** * Offset of the field that holds the disk number of the first * central directory entry inside the "End of central directory * record" relative to the start of the "End of central directory * record". */ private static final int CFD_DISK_OFFSET = /* end of central dir signature */ ZipConstants.WORD /* number of this disk */ + ZipConstants.SHORT; /** * Offset of the field that holds the location of the first * central directory entry inside the "End of central directory * record" relative to the "number of the disk with the start * of the central directory". */ private static final int CFD_LOCATOR_RELATIVE_OFFSET = /* total number of entries in */ /* the central dir on this disk */ + ZipConstants.SHORT /* total number of entries in */ /* the central dir */ + ZipConstants.SHORT /* size of the central directory */ + ZipConstants.WORD; /** * Length of the "Zip64 end of central directory locator" - which * should be right in front of the "end of central directory * record" if one is present at all. */ private static final int ZIP64_EOCDL_LENGTH = /* zip64 end of central dir locator sig */ ZipConstants.WORD /* number of the disk with the start */ /* start of the zip64 end of */ /* central directory */ + ZipConstants.WORD /* relative offset of the zip64 */ /* end of central directory record */ + ZipConstants.DWORD /* total number of disks */ + ZipConstants.WORD; /** * Offset of the field that holds the location of the "Zip64 end * of central directory record" inside the "Zip64 end of central * directory locator" relative to the start of the "Zip64 end of * central directory locator". */ private static final int ZIP64_EOCDL_LOCATOR_OFFSET = /* zip64 end of central dir locator sig */ ZipConstants.WORD /* number of the disk with the start */ /* start of the zip64 end of */ /* central directory */ + ZipConstants.WORD; /** * Offset of the field that holds the location of the first * central directory entry inside the "Zip64 end of central * directory record" relative to the start of the "Zip64 end of * central directory record". */ private static final int ZIP64_EOCD_CFD_LOCATOR_OFFSET = /* zip64 end of central dir */ /* signature */ ZipConstants.WORD /* size of zip64 end of central */ /* directory record */ + ZipConstants.DWORD /* version made by */ + ZipConstants.SHORT /* version needed to extract */ + ZipConstants.SHORT /* number of this disk */ + ZipConstants.WORD /* number of the disk with the */ /* start of the central directory */ + ZipConstants.WORD /* total number of entries in the */ /* central directory on this disk */ + ZipConstants.DWORD /* total number of entries in the */ /* central directory */ + ZipConstants.DWORD /* size of the central directory */ + ZipConstants.DWORD; /** * Offset of the field that holds the disk number of the first * central directory entry inside the "Zip64 end of central * directory record" relative to the start of the "Zip64 end of * central directory record". */ private static final int ZIP64_EOCD_CFD_DISK_OFFSET = /* zip64 end of central dir */ /* signature */ ZipConstants.WORD /* size of zip64 end of central */ /* directory record */ + ZipConstants.DWORD /* version made by */ + ZipConstants.SHORT /* version needed to extract */ + ZipConstants.SHORT /* number of this disk */ + ZipConstants.WORD; /** * Offset of the field that holds the location of the first * central directory entry inside the "Zip64 end of central * directory record" relative to the "number of the disk * with the start of the central directory". */ private static final int ZIP64_EOCD_CFD_LOCATOR_RELATIVE_OFFSET = /* total number of entries in the */ /* central directory on this disk */ ZipConstants.DWORD /* total number of entries in the */ /* central directory */ + ZipConstants.DWORD /* size of the central directory */ + ZipConstants.DWORD; /** * Number of bytes in local file header up to the "length of * file name" entry. */ private static final long LFH_OFFSET_FOR_FILENAME_LENGTH = /* local file header signature */ ZipConstants.WORD /* version needed to extract */ + ZipConstants.SHORT /* general purpose bit flag */ + ZipConstants.SHORT /* compression method */ + ZipConstants.SHORT /* last mod file time */ + ZipConstants.SHORT /* last mod file date */ + ZipConstants.SHORT /* crc-32 */ + ZipConstants.WORD /* compressed size */ + ZipConstants.WORD /* uncompressed size */ + (long) ZipConstants.WORD; /** * Compares two ZipArchiveEntries based on their offset within the archive. * *

Won't return any meaningful results if one of the entries * isn't part of the archive at all.

* * @since 1.1 */ private static final Comparator offsetComparator = Comparator.comparingLong(ZipArchiveEntry::getDiskNumberStart) .thenComparingLong(ZipArchiveEntry::getLocalHeaderOffset); /** * Closes a ZIP file quietly; throwing no IOException, dooes nothing * on null input. * @param zipFile file to close, can be null */ public static void closeQuietly(final ZipFile zipFile) { IOUtils.closeQuietly(zipFile); } /** * List of entries in the order they appear inside the central * directory. */ private final List entries = new LinkedList<>(); /** * Maps String to list of ZipArchiveEntrys, name -> actual entries. */ private final Map> nameMap = new HashMap<>(HASH_SIZE); /** * The encoding to use for file names and the file comment. * *

For a list of possible values see http://java.sun.com/j2se/1.5.0/docs/guide/intl/encoding.doc.html. * Defaults to UTF-8.

*/ private final String encoding; /** * The ZIP encoding to use for file names and the file comment. */ private final ZipEncoding zipEncoding; /** * File name of actual source. */ private final String archiveName; /** * The actual data source. */ private final SeekableByteChannel archive; /** * Whether to look for and use Unicode extra fields. */ private final boolean useUnicodeExtraFields; /** * Whether the file is closed. */ private volatile boolean closed = true; /** * Whether the ZIP archive is a split ZIP archive */ private final boolean isSplitZipArchive; // cached buffers - must only be used locally in the class (COMPRESS-172 - reduce garbage collection) private final byte[] dwordBuf = new byte[ZipConstants.DWORD]; private final byte[] wordBuf = new byte[ZipConstants.WORD]; private final byte[] cfhBuf = new byte[CFH_LEN]; private final byte[] shortBuf = new byte[ZipConstants.SHORT]; private final ByteBuffer dwordBbuf = ByteBuffer.wrap(dwordBuf); private final ByteBuffer wordBbuf = ByteBuffer.wrap(wordBuf); private final ByteBuffer cfhBbuf = ByteBuffer.wrap(cfhBuf); private final ByteBuffer shortBbuf = ByteBuffer.wrap(shortBuf); private long centralDirectoryStartDiskNumber, centralDirectoryStartRelativeOffset; private long centralDirectoryStartOffset; private long firstLocalFileHeaderOffset; /** * Opens the given file for reading, assuming "UTF8" for file names. * * @param f the archive. * * @throws IOException if an error occurs while reading the file. */ public ZipFile(final File f) throws IOException { this(f, ZipEncodingHelper.UTF8); } /** * Opens the given file for reading, assuming the specified * encoding for file names and scanning for Unicode extra fields. * * @param f the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * * @throws IOException if an error occurs while reading the file. */ public ZipFile(final File f, final String encoding) throws IOException { this(f.toPath(), encoding, true); } /** * Opens the given file for reading, assuming the specified * encoding for file names. * * @param f the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @param useUnicodeExtraFields whether to use InfoZIP Unicode * Extra Fields (if present) to set the file names. * * @throws IOException if an error occurs while reading the file. */ public ZipFile(final File f, final String encoding, final boolean useUnicodeExtraFields) throws IOException { this(f.toPath(), encoding, useUnicodeExtraFields, false); } /** * Opens the given file for reading, assuming the specified * encoding for file names. * *

By default the central directory record and all local file headers of the archive will be read immediately * which may take a considerable amount of time when the archive is big. The {@code ignoreLocalFileHeader} parameter * can be set to {@code true} which restricts parsing to the central directory. Unfortunately the local file header * may contain information not present inside of the central directory which will not be available when the argument * is set to {@code true}. This includes the content of the Unicode extra field, so setting {@code * ignoreLocalFileHeader} to {@code true} means {@code useUnicodeExtraFields} will be ignored effectively.

* * @param f the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @param useUnicodeExtraFields whether to use InfoZIP Unicode * Extra Fields (if present) to set the file names. * @param ignoreLocalFileHeader whether to ignore information * stored inside the local file header (see the notes in this method's javadoc) * * @throws IOException if an error occurs while reading the file. * @since 1.19 */ public ZipFile(final File f, final String encoding, final boolean useUnicodeExtraFields, final boolean ignoreLocalFileHeader) throws IOException { this(Files.newByteChannel(f.toPath(), EnumSet.of(StandardOpenOption.READ)), f.getAbsolutePath(), encoding, useUnicodeExtraFields, true, ignoreLocalFileHeader); } /** * Opens the given path for reading, assuming "UTF8" for file names. * * @param path path to the archive. * @throws IOException if an error occurs while reading the file. * @since 1.22 */ public ZipFile(final Path path) throws IOException { this(path, ZipEncodingHelper.UTF8); } /** * Opens the given path for reading, assuming the specified * encoding for file names and scanning for Unicode extra fields. * * @param path path to the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @throws IOException if an error occurs while reading the file. * @since 1.22 */ public ZipFile(final Path path, final String encoding) throws IOException { this(path, encoding, true); } /** * Opens the given path for reading, assuming the specified * encoding for file names. * * @param path path to the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @param useUnicodeExtraFields whether to use InfoZIP Unicode * Extra Fields (if present) to set the file names. * @throws IOException if an error occurs while reading the file. * @since 1.22 */ public ZipFile(final Path path, final String encoding, final boolean useUnicodeExtraFields) throws IOException { this(path, encoding, useUnicodeExtraFields, false); } /** * Opens the given path for reading, assuming the specified * encoding for file names. *

By default the central directory record and all local file headers of the archive will be read immediately * which may take a considerable amount of time when the archive is big. The {@code ignoreLocalFileHeader} parameter * can be set to {@code true} which restricts parsing to the central directory. Unfortunately the local file header * may contain information not present inside of the central directory which will not be available when the argument * is set to {@code true}. This includes the content of the Unicode extra field, so setting {@code * ignoreLocalFileHeader} to {@code true} means {@code useUnicodeExtraFields} will be ignored effectively.

* * @param path path to the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @param useUnicodeExtraFields whether to use InfoZIP Unicode * Extra Fields (if present) to set the file names. * @param ignoreLocalFileHeader whether to ignore information * stored inside the local file header (see the notes in this method's javadoc) * @throws IOException if an error occurs while reading the file. * @since 1.22 */ public ZipFile(final Path path, final String encoding, final boolean useUnicodeExtraFields, final boolean ignoreLocalFileHeader) throws IOException { this(Files.newByteChannel(path, EnumSet.of(StandardOpenOption.READ)), path.toAbsolutePath().toString(), encoding, useUnicodeExtraFields, true, ignoreLocalFileHeader); } /** * Opens the given channel for reading, assuming "UTF8" for file names. * *

{@link * org.apache.commons.compress.utils.SeekableInMemoryByteChannel} * allows you to read from an in-memory archive.

* * @param channel the archive. * * @throws IOException if an error occurs while reading the file. * @since 1.13 */ public ZipFile(final SeekableByteChannel channel) throws IOException { this(channel, "unknown archive", ZipEncodingHelper.UTF8, true); } /** * Opens the given channel for reading, assuming the specified * encoding for file names. * *

{@link * org.apache.commons.compress.utils.SeekableInMemoryByteChannel} * allows you to read from an in-memory archive.

* * @param channel the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * * @throws IOException if an error occurs while reading the file. * @since 1.13 */ public ZipFile(final SeekableByteChannel channel, final String encoding) throws IOException { this(channel, "unknown archive", encoding, true); } /** * Opens the given channel for reading, assuming the specified * encoding for file names. * *

{@link * org.apache.commons.compress.utils.SeekableInMemoryByteChannel} * allows you to read from an in-memory archive.

* * @param channel the archive. * @param archiveName name of the archive, used for error messages only. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @param useUnicodeExtraFields whether to use InfoZIP Unicode * Extra Fields (if present) to set the file names. * * @throws IOException if an error occurs while reading the file. * @since 1.13 */ public ZipFile(final SeekableByteChannel channel, final String archiveName, final String encoding, final boolean useUnicodeExtraFields) throws IOException { this(channel, archiveName, encoding, useUnicodeExtraFields, false, false); } /** * Opens the given channel for reading, assuming the specified * encoding for file names. * *

{@link * org.apache.commons.compress.utils.SeekableInMemoryByteChannel} * allows you to read from an in-memory archive.

* *

By default the central directory record and all local file headers of the archive will be read immediately * which may take a considerable amount of time when the archive is big. The {@code ignoreLocalFileHeader} parameter * can be set to {@code true} which restricts parsing to the central directory. Unfortunately the local file header * may contain information not present inside of the central directory which will not be available when the argument * is set to {@code true}. This includes the content of the Unicode extra field, so setting {@code * ignoreLocalFileHeader} to {@code true} means {@code useUnicodeExtraFields} will be ignored effectively.

* * @param channel the archive. * @param archiveName name of the archive, used for error messages only. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * @param useUnicodeExtraFields whether to use InfoZIP Unicode * Extra Fields (if present) to set the file names. * @param ignoreLocalFileHeader whether to ignore information * stored inside the local file header (see the notes in this method's javadoc) * * @throws IOException if an error occurs while reading the file. * @since 1.19 */ public ZipFile(final SeekableByteChannel channel, final String archiveName, final String encoding, final boolean useUnicodeExtraFields, final boolean ignoreLocalFileHeader) throws IOException { this(channel, archiveName, encoding, useUnicodeExtraFields, false, ignoreLocalFileHeader); } private ZipFile(final SeekableByteChannel channel, final String archiveName, final String encoding, final boolean useUnicodeExtraFields, final boolean closeOnError, final boolean ignoreLocalFileHeader) throws IOException { isSplitZipArchive = (channel instanceof ZipSplitReadOnlySeekableByteChannel); this.archiveName = archiveName; this.encoding = encoding; this.zipEncoding = ZipEncodingHelper.getZipEncoding(encoding); this.useUnicodeExtraFields = useUnicodeExtraFields; archive = channel; boolean success = false; try { final Map entriesWithoutUTF8Flag = populateFromCentralDirectory(); if (!ignoreLocalFileHeader) { resolveLocalFileHeaderData(entriesWithoutUTF8Flag); } fillNameMap(); success = true; } catch (final IOException e) { throw new IOException("Error on ZipFile " + archiveName, e); } finally { closed = !success; if (!success && closeOnError) { IOUtils.closeQuietly(archive); } } } /** * Opens the given file for reading, assuming "UTF8". * * @param name name of the archive. * * @throws IOException if an error occurs while reading the file. */ public ZipFile(final String name) throws IOException { this(new File(name).toPath(), ZipEncodingHelper.UTF8); } /** * Opens the given file for reading, assuming the specified * encoding for file names, scanning unicode extra fields. * * @param name name of the archive. * @param encoding the encoding to use for file names, use null * for the platform's default encoding * * @throws IOException if an error occurs while reading the file. */ public ZipFile(final String name, final String encoding) throws IOException { this(new File(name).toPath(), encoding, true); } /** * Whether this class is able to read the given entry. * *

May return false if it is set up to use encryption or a * compression method that hasn't been implemented yet.

* @since 1.1 * @param ze the entry * @return whether this class is able to read the given entry. */ public boolean canReadEntryData(final ZipArchiveEntry ze) { return ZipUtil.canHandleEntryData(ze); } /** * Closes the archive. * @throws IOException if an error occurs closing the archive. */ @Override public void close() throws IOException { // this flag is only written here and read in finalize() which // can never be run in parallel. // no synchronization needed. closed = true; archive.close(); } /** * Transfer selected entries from this ZIP file to a given #ZipArchiveOutputStream. * Compression and all other attributes will be as in this file. *

This method transfers entries based on the central directory of the ZIP file.

* * @param target The zipArchiveOutputStream to write the entries to * @param predicate A predicate that selects which entries to write * @throws IOException on error */ public void copyRawEntries(final ZipArchiveOutputStream target, final ZipArchiveEntryPredicate predicate) throws IOException { final Enumeration src = getEntriesInPhysicalOrder(); while (src.hasMoreElements()) { final ZipArchiveEntry entry = src.nextElement(); if (predicate.test( entry)) { target.addRawArchiveEntry(entry, getRawInputStream(entry)); } } } /** * Creates new BoundedInputStream, according to implementation of * underlying archive channel. */ private BoundedArchiveInputStream createBoundedInputStream(final long start, final long remaining) { if (start < 0 || remaining < 0 || start + remaining < start) { throw new IllegalArgumentException("Corrupted archive, stream boundaries" + " are out of range"); } return archive instanceof FileChannel ? new BoundedFileChannelInputStream(start, remaining) : new BoundedSeekableByteChannelInputStream(start, remaining, archive); } private void fillNameMap() { entries.forEach(ze -> { // entries is filled in populateFromCentralDirectory and // never modified final String name = ze.getName(); final LinkedList entriesOfThatName = nameMap.computeIfAbsent(name, k -> new LinkedList<>()); entriesOfThatName.addLast(ze); }); } /** * Ensures that the close method of this ZIP file is called when * there are no more references to it. * @see #close() */ @Override protected void finalize() throws Throwable { try { if (!closed) { close(); } } finally { super.finalize(); } } /** * Gets an InputStream for reading the content before the first local file header. * * @return null if there is no content before the first local file header. * Otherwise returns a stream to read the content before the first local file header. * @since 1.23 */ public InputStream getContentBeforeFirstLocalFileHeader() { return firstLocalFileHeaderOffset == 0 ? null : createBoundedInputStream(0, firstLocalFileHeaderOffset); } private long getDataOffset(final ZipArchiveEntry ze) throws IOException { final long s = ze.getDataOffset(); if (s == EntryStreamOffsets.OFFSET_UNKNOWN) { setDataOffset(ze); return ze.getDataOffset(); } return s; } /** * Gets the encoding to use for file names and the file comment. * * @return null if using the platform's default character encoding. */ public String getEncoding() { return encoding; } /** * Gets all entries. * *

Entries will be returned in the same order they appear * within the archive's central directory.

* * @return all entries as {@link ZipArchiveEntry} instances */ public Enumeration getEntries() { return Collections.enumeration(entries); } /** * Gets all named entries in the same order they appear within * the archive's central directory. * * @param name name of the entry. * @return the Iterable<ZipArchiveEntry> corresponding to the * given name * @since 1.6 */ public Iterable getEntries(final String name) { final List entriesOfThatName = nameMap.get(name); return entriesOfThatName != null ? entriesOfThatName : Collections.emptyList(); } /** * Gets all entries in physical order. * *

Entries will be returned in the same order their contents * appear within the archive.

* * @return all entries as {@link ZipArchiveEntry} instances * * @since 1.1 */ public Enumeration getEntriesInPhysicalOrder() { final ZipArchiveEntry[] allEntries = entries.toArray(ZipArchiveEntry.EMPTY_ARRAY); Arrays.sort(allEntries, offsetComparator); return Collections.enumeration(Arrays.asList(allEntries)); } /** * Gets all named entries in the same order their contents * appear within the archive. * * @param name name of the entry. * @return the Iterable<ZipArchiveEntry> corresponding to the * given name * @since 1.6 */ public Iterable getEntriesInPhysicalOrder(final String name) { ZipArchiveEntry[] entriesOfThatName = ZipArchiveEntry.EMPTY_ARRAY; final LinkedList linkedList = nameMap.get(name); if (linkedList != null) { entriesOfThatName = linkedList.toArray(entriesOfThatName); Arrays.sort(entriesOfThatName, offsetComparator); } return Arrays.asList(entriesOfThatName); } /** * Gets a named entry or {@code null} if no entry by * that name exists. * *

If multiple entries with the same name exist the first entry * in the archive's central directory by that name is * returned.

* * @param name name of the entry. * @return the ZipArchiveEntry corresponding to the given name - or * {@code null} if not present. */ public ZipArchiveEntry getEntry(final String name) { final LinkedList entriesOfThatName = nameMap.get(name); return entriesOfThatName != null ? entriesOfThatName.getFirst() : null; } /** * Gets the offset of the first local file header in the file. * * @return the length of the content before the first local file header * @since 1.23 */ public long getFirstLocalFileHeaderOffset() { return firstLocalFileHeaderOffset; } /** * Gets an InputStream for reading the contents of the given entry. * * @param zipEntry the entry to get the stream for. * @return a stream to read the entry from. The returned stream * implements {@link InputStreamStatistics}. * @throws IOException if unable to create an input stream from the zipEntry. */ public InputStream getInputStream(final ZipArchiveEntry zipEntry) throws IOException { if (!(zipEntry instanceof Entry)) { return null; } // cast validity is checked just above ZipUtil.checkRequestedFeatures(zipEntry); // doesn't get closed if the method is not supported - which // should never happen because of the checkRequestedFeatures // call above final InputStream is = new BufferedInputStream(getRawInputStream(zipEntry)); //NOSONAR switch (ZipMethod.getMethodByCode(zipEntry.getMethod())) { case STORED: return new StoredStatisticsStream(is); case UNSHRINKING: return new UnshrinkingInputStream(is); case IMPLODING: try { return new ExplodingInputStream(zipEntry.getGeneralPurposeBit().getSlidingDictionarySize(), zipEntry.getGeneralPurposeBit().getNumberOfShannonFanoTrees(), is); } catch (final IllegalArgumentException ex) { throw new IOException("bad IMPLODE data", ex); } case DEFLATED: final Inflater inflater = new Inflater(true); // Inflater with nowrap=true has this odd contract for a zero padding // byte following the data stream; this used to be zlib's requirement // and has been fixed a long time ago, but the contract persists so // we comply. // https://docs.oracle.com/javase/7/docs/api/java/util/zip/Inflater.html#Inflater(boolean) return new InflaterInputStreamWithStatistics(new SequenceInputStream(is, new ByteArrayInputStream(ONE_ZERO_BYTE)), inflater) { @Override public void close() throws IOException { try { super.close(); } finally { inflater.end(); } } }; case BZIP2: return new BZip2CompressorInputStream(is); case ENHANCED_DEFLATED: return new Deflate64CompressorInputStream(is); case AES_ENCRYPTED: case EXPANDING_LEVEL_1: case EXPANDING_LEVEL_2: case EXPANDING_LEVEL_3: case EXPANDING_LEVEL_4: case JPEG: case LZMA: case PKWARE_IMPLODING: case PPMD: case TOKENIZATION: case UNKNOWN: case WAVPACK: case XZ: default: throw new UnsupportedZipFeatureException(ZipMethod.getMethodByCode(zipEntry.getMethod()), zipEntry); } } /** * Gets the raw stream of the archive entry (compressed form). * *

This method does not relate to how/if we understand the payload in the * stream, since we really only intend to move it on to somewhere else.

* *

Since version 1.22, this method will make an attempt to read the entry's data * stream offset, even if the {@code ignoreLocalFileHeader} parameter was {@code true} * in the constructor. An IOException can also be thrown from the body of the method * if this lookup fails for some reason.

* * @param ze The entry to get the stream for * @return The raw input stream containing (possibly) compressed data. * @since 1.11 * @throws IOException if there is a problem reading data offset (added in version 1.22). */ public InputStream getRawInputStream(final ZipArchiveEntry ze) throws IOException { if (!(ze instanceof Entry)) { return null; } final long start = getDataOffset(ze); if (start == EntryStreamOffsets.OFFSET_UNKNOWN) { return null; } return createBoundedInputStream(start, ze.getCompressedSize()); } /** * Gets the entry's content as a String if isUnixSymlink() * returns true for it, otherwise returns null. *

This method assumes the symbolic link's file name uses the * same encoding that as been specified for this ZipFile.

* * @param entry ZipArchiveEntry object that represents the symbolic link * @return entry's content as a String * @throws IOException problem with content's input stream * @since 1.5 */ public String getUnixSymlink(final ZipArchiveEntry entry) throws IOException { if (entry != null && entry.isUnixSymlink()) { try (InputStream in = getInputStream(entry)) { return zipEncoding.decode(IOUtils.toByteArray(in)); } } return null; } /** * Reads the central directory of the given archive and populates * the internal tables with ZipArchiveEntry instances. * *

The ZipArchiveEntrys will know all data that can be obtained from * the central directory alone, but not the data that requires the * local file header or additional data to be read.

* * @return a map of zipentries that didn't have the language * encoding flag set when read. */ private Map populateFromCentralDirectory() throws IOException { final HashMap noUTF8Flag = new HashMap<>(); positionAtCentralDirectory(); centralDirectoryStartOffset = archive.position(); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); long sig = ZipLong.getValue(wordBuf); if (sig != CFH_SIG && startsWithLocalFileHeader()) { throw new IOException("Central directory is empty, can't expand" + " corrupt archive."); } while (sig == CFH_SIG) { readCentralDirectoryEntry(noUTF8Flag); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); sig = ZipLong.getValue(wordBuf); } return noUTF8Flag; } /** * Searches for either the "Zip64 end of central directory * locator" or the "End of central dir record", parses * it and positions the stream at the first central directory * record. */ private void positionAtCentralDirectory() throws IOException { positionAtEndOfCentralDirectoryRecord(); boolean found = false; final boolean searchedForZip64EOCD = archive.position() > ZIP64_EOCDL_LENGTH; if (searchedForZip64EOCD) { archive.position(archive.position() - ZIP64_EOCDL_LENGTH); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); found = Arrays.equals(ZipArchiveOutputStream.ZIP64_EOCD_LOC_SIG, wordBuf); } if (!found) { // not a ZIP64 archive if (searchedForZip64EOCD) { skipBytes(ZIP64_EOCDL_LENGTH - ZipConstants.WORD); } positionAtCentralDirectory32(); } else { positionAtCentralDirectory64(); } } /** * Parses the "End of central dir record" and positions * the stream at the first central directory record. * * Expects stream to be positioned at the beginning of the * "End of central dir record". */ private void positionAtCentralDirectory32() throws IOException { final long endOfCentralDirectoryRecordOffset = archive.position(); if (isSplitZipArchive) { skipBytes(CFD_DISK_OFFSET); shortBbuf.rewind(); IOUtils.readFully(archive, shortBbuf); centralDirectoryStartDiskNumber = ZipShort.getValue(shortBuf); skipBytes(CFD_LOCATOR_RELATIVE_OFFSET); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); centralDirectoryStartRelativeOffset = ZipLong.getValue(wordBuf); ((ZipSplitReadOnlySeekableByteChannel) archive) .position(centralDirectoryStartDiskNumber, centralDirectoryStartRelativeOffset); } else { skipBytes(CFD_LENGTH_OFFSET); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); final long centralDirectoryLength = ZipLong.getValue(wordBuf); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); centralDirectoryStartDiskNumber = 0; centralDirectoryStartRelativeOffset = ZipLong.getValue(wordBuf); firstLocalFileHeaderOffset = Long.max( endOfCentralDirectoryRecordOffset - centralDirectoryLength - centralDirectoryStartRelativeOffset, 0L); archive.position(centralDirectoryStartRelativeOffset + firstLocalFileHeaderOffset); } } /** * Parses the "Zip64 end of central directory locator", * finds the "Zip64 end of central directory record" using the * parsed information, parses that and positions the stream at the * first central directory record. * * Expects stream to be positioned right behind the "Zip64 * end of central directory locator"'s signature. */ private void positionAtCentralDirectory64() throws IOException { if (isSplitZipArchive) { wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); final long diskNumberOfEOCD = ZipLong.getValue(wordBuf); dwordBbuf.rewind(); IOUtils.readFully(archive, dwordBbuf); final long relativeOffsetOfEOCD = ZipEightByteInteger.getLongValue(dwordBuf); ((ZipSplitReadOnlySeekableByteChannel) archive) .position(diskNumberOfEOCD, relativeOffsetOfEOCD); } else { skipBytes(ZIP64_EOCDL_LOCATOR_OFFSET - ZipConstants.WORD /* signature has already been read */); dwordBbuf.rewind(); IOUtils.readFully(archive, dwordBbuf); archive.position(ZipEightByteInteger.getLongValue(dwordBuf)); } wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); if (!Arrays.equals(wordBuf, ZipArchiveOutputStream.ZIP64_EOCD_SIG)) { throw new ZipException("Archive's ZIP64 end of central " + "directory locator is corrupt."); } if (isSplitZipArchive) { skipBytes(ZIP64_EOCD_CFD_DISK_OFFSET - ZipConstants.WORD /* signature has already been read */); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); centralDirectoryStartDiskNumber = ZipLong.getValue(wordBuf); skipBytes(ZIP64_EOCD_CFD_LOCATOR_RELATIVE_OFFSET); dwordBbuf.rewind(); IOUtils.readFully(archive, dwordBbuf); centralDirectoryStartRelativeOffset = ZipEightByteInteger.getLongValue(dwordBuf); ((ZipSplitReadOnlySeekableByteChannel) archive) .position(centralDirectoryStartDiskNumber, centralDirectoryStartRelativeOffset); } else { skipBytes(ZIP64_EOCD_CFD_LOCATOR_OFFSET - ZipConstants.WORD /* signature has already been read */); dwordBbuf.rewind(); IOUtils.readFully(archive, dwordBbuf); centralDirectoryStartDiskNumber = 0; centralDirectoryStartRelativeOffset = ZipEightByteInteger.getLongValue(dwordBuf); archive.position(centralDirectoryStartRelativeOffset); } } /** * Searches for the and positions the stream at the start of the * "End of central dir record". */ private void positionAtEndOfCentralDirectoryRecord() throws IOException { final boolean found = tryToLocateSignature(MIN_EOCD_SIZE, MAX_EOCD_SIZE, ZipArchiveOutputStream.EOCD_SIG); if (!found) { throw new ZipException("Archive is not a ZIP archive"); } } /** * Reads an individual entry of the central directory, creats an * ZipArchiveEntry from it and adds it to the global maps. * * @param noUTF8Flag map used to collect entries that don't have * their UTF-8 flag set and whose name will be set by data read * from the local file header later. The current entry may be * added to this map. */ private void readCentralDirectoryEntry(final Map noUTF8Flag) throws IOException { cfhBbuf.rewind(); IOUtils.readFully(archive, cfhBbuf); int off = 0; final Entry ze = new Entry(); final int versionMadeBy = ZipShort.getValue(cfhBuf, off); off += ZipConstants.SHORT; ze.setVersionMadeBy(versionMadeBy); ze.setPlatform((versionMadeBy >> BYTE_SHIFT) & NIBLET_MASK); ze.setVersionRequired(ZipShort.getValue(cfhBuf, off)); off += ZipConstants.SHORT; // version required final GeneralPurposeBit gpFlag = GeneralPurposeBit.parse(cfhBuf, off); final boolean hasUTF8Flag = gpFlag.usesUTF8ForNames(); final ZipEncoding entryEncoding = hasUTF8Flag ? ZipEncodingHelper.UTF8_ZIP_ENCODING : zipEncoding; if (hasUTF8Flag) { ze.setNameSource(ZipArchiveEntry.NameSource.NAME_WITH_EFS_FLAG); } ze.setGeneralPurposeBit(gpFlag); ze.setRawFlag(ZipShort.getValue(cfhBuf, off)); off += ZipConstants.SHORT; //noinspection MagicConstant ze.setMethod(ZipShort.getValue(cfhBuf, off)); off += ZipConstants.SHORT; final long time = ZipUtil.dosToJavaTime(ZipLong.getValue(cfhBuf, off)); ze.setTime(time); off += ZipConstants.WORD; ze.setCrc(ZipLong.getValue(cfhBuf, off)); off += ZipConstants.WORD; long size = ZipLong.getValue(cfhBuf, off); if (size < 0) { throw new IOException("broken archive, entry with negative compressed size"); } ze.setCompressedSize(size); off += ZipConstants.WORD; size = ZipLong.getValue(cfhBuf, off); if (size < 0) { throw new IOException("broken archive, entry with negative size"); } ze.setSize(size); off += ZipConstants.WORD; final int fileNameLen = ZipShort.getValue(cfhBuf, off); off += ZipConstants.SHORT; if (fileNameLen < 0) { throw new IOException("broken archive, entry with negative fileNameLen"); } final int extraLen = ZipShort.getValue(cfhBuf, off); off += ZipConstants.SHORT; if (extraLen < 0) { throw new IOException("broken archive, entry with negative extraLen"); } final int commentLen = ZipShort.getValue(cfhBuf, off); off += ZipConstants.SHORT; if (commentLen < 0) { throw new IOException("broken archive, entry with negative commentLen"); } ze.setDiskNumberStart(ZipShort.getValue(cfhBuf, off)); off += ZipConstants.SHORT; ze.setInternalAttributes(ZipShort.getValue(cfhBuf, off)); off += ZipConstants.SHORT; ze.setExternalAttributes(ZipLong.getValue(cfhBuf, off)); off += ZipConstants.WORD; final byte[] fileName = IOUtils.readRange(archive, fileNameLen); if (fileName.length < fileNameLen) { throw new EOFException(); } ze.setName(entryEncoding.decode(fileName), fileName); // LFH offset, ze.setLocalHeaderOffset(ZipLong.getValue(cfhBuf, off) + firstLocalFileHeaderOffset); // data offset will be filled later entries.add(ze); final byte[] cdExtraData = IOUtils.readRange(archive, extraLen); if (cdExtraData.length < extraLen) { throw new EOFException(); } try { ze.setCentralDirectoryExtra(cdExtraData); } catch (final RuntimeException ex) { final ZipException z = new ZipException("Invalid extra data in entry " + ze.getName()); z.initCause(ex); throw z; } setSizesAndOffsetFromZip64Extra(ze); sanityCheckLFHOffset(ze); final byte[] comment = IOUtils.readRange(archive, commentLen); if (comment.length < commentLen) { throw new EOFException(); } ze.setComment(entryEncoding.decode(comment)); if (!hasUTF8Flag && useUnicodeExtraFields) { noUTF8Flag.put(ze, new NameAndComment(fileName, comment)); } ze.setStreamContiguous(true); } /** * Walks through all recorded entries and adds the data available * from the local file header. * *

Also records the offsets for the data to read from the * entries.

*/ private void resolveLocalFileHeaderData(final Map entriesWithoutUTF8Flag) throws IOException { for (final ZipArchiveEntry zipArchiveEntry : entries) { // entries is filled in populateFromCentralDirectory and // never modified final Entry ze = (Entry) zipArchiveEntry; final int[] lens = setDataOffset(ze); final int fileNameLen = lens[0]; final int extraFieldLen = lens[1]; skipBytes(fileNameLen); final byte[] localExtraData = IOUtils.readRange(archive, extraFieldLen); if (localExtraData.length < extraFieldLen) { throw new EOFException(); } try { ze.setExtra(localExtraData); } catch (final RuntimeException ex) { final ZipException z = new ZipException("Invalid extra data in entry " + ze.getName()); z.initCause(ex); throw z; } if (entriesWithoutUTF8Flag.containsKey(ze)) { final NameAndComment nc = entriesWithoutUTF8Flag.get(ze); ZipUtil.setNameAndCommentFromExtraFields(ze, nc.name, nc.comment); } } } private void sanityCheckLFHOffset(final ZipArchiveEntry ze) throws IOException { if (ze.getDiskNumberStart() < 0) { throw new IOException("broken archive, entry with negative disk number"); } if (ze.getLocalHeaderOffset() < 0) { throw new IOException("broken archive, entry with negative local file header offset"); } if (isSplitZipArchive) { if (ze.getDiskNumberStart() > centralDirectoryStartDiskNumber) { throw new IOException("local file header for " + ze.getName() + " starts on a later disk than central directory"); } if (ze.getDiskNumberStart() == centralDirectoryStartDiskNumber && ze.getLocalHeaderOffset() > centralDirectoryStartRelativeOffset) { throw new IOException("local file header for " + ze.getName() + " starts after central directory"); } } else if (ze.getLocalHeaderOffset() > centralDirectoryStartOffset) { throw new IOException("local file header for " + ze.getName() + " starts after central directory"); } } private int[] setDataOffset(final ZipArchiveEntry ze) throws IOException { long offset = ze.getLocalHeaderOffset(); if (isSplitZipArchive) { ((ZipSplitReadOnlySeekableByteChannel) archive) .position(ze.getDiskNumberStart(), offset + LFH_OFFSET_FOR_FILENAME_LENGTH); // the offset should be updated to the global offset offset = archive.position() - LFH_OFFSET_FOR_FILENAME_LENGTH; } else { archive.position(offset + LFH_OFFSET_FOR_FILENAME_LENGTH); } wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); wordBbuf.flip(); wordBbuf.get(shortBuf); final int fileNameLen = ZipShort.getValue(shortBuf); wordBbuf.get(shortBuf); final int extraFieldLen = ZipShort.getValue(shortBuf); ze.setDataOffset(offset + LFH_OFFSET_FOR_FILENAME_LENGTH + ZipConstants.SHORT + ZipConstants.SHORT + fileNameLen + extraFieldLen); if (ze.getDataOffset() + ze.getCompressedSize() > centralDirectoryStartOffset) { throw new IOException("data for " + ze.getName() + " overlaps with central directory."); } return new int[] { fileNameLen, extraFieldLen }; } /** * If the entry holds a Zip64 extended information extra field, * read sizes from there if the entry's sizes are set to * 0xFFFFFFFFF, do the same for the offset of the local file * header. * *

Ensures the Zip64 extra either knows both compressed and * uncompressed size or neither of both as the internal logic in * ExtraFieldUtils forces the field to create local header data * even if they are never used - and here a field with only one * size would be invalid.

*/ private void setSizesAndOffsetFromZip64Extra(final ZipArchiveEntry ze) throws IOException { final ZipExtraField extra = ze.getExtraField(Zip64ExtendedInformationExtraField.HEADER_ID); if (extra != null && !(extra instanceof Zip64ExtendedInformationExtraField)) { throw new ZipException("archive contains unparseable zip64 extra field"); } final Zip64ExtendedInformationExtraField z64 = (Zip64ExtendedInformationExtraField) extra; if (z64 != null) { final boolean hasUncompressedSize = ze.getSize() == ZipConstants.ZIP64_MAGIC; final boolean hasCompressedSize = ze.getCompressedSize() == ZipConstants.ZIP64_MAGIC; final boolean hasRelativeHeaderOffset = ze.getLocalHeaderOffset() == ZipConstants.ZIP64_MAGIC; final boolean hasDiskStart = ze.getDiskNumberStart() == ZipConstants.ZIP64_MAGIC_SHORT; z64.reparseCentralDirectoryData(hasUncompressedSize, hasCompressedSize, hasRelativeHeaderOffset, hasDiskStart); if (hasUncompressedSize) { final long size = z64.getSize().getLongValue(); if (size < 0) { throw new IOException("broken archive, entry with negative size"); } ze.setSize(size); } else if (hasCompressedSize) { z64.setSize(new ZipEightByteInteger(ze.getSize())); } if (hasCompressedSize) { final long size = z64.getCompressedSize().getLongValue(); if (size < 0) { throw new IOException("broken archive, entry with negative compressed size"); } ze.setCompressedSize(size); } else if (hasUncompressedSize) { z64.setCompressedSize(new ZipEightByteInteger(ze.getCompressedSize())); } if (hasRelativeHeaderOffset) { ze.setLocalHeaderOffset(z64.getRelativeHeaderOffset().getLongValue()); } if (hasDiskStart) { ze.setDiskNumberStart(z64.getDiskStartNumber().getValue()); } } } /** * Skips the given number of bytes or throws an EOFException if * skipping failed. */ private void skipBytes(final int count) throws IOException { final long currentPosition = archive.position(); final long newPosition = currentPosition + count; if (newPosition > archive.size()) { throw new EOFException(); } archive.position(newPosition); } /** * Checks whether the archive starts with a LFH. If it doesn't, * it may be an empty archive. */ private boolean startsWithLocalFileHeader() throws IOException { archive.position(firstLocalFileHeaderOffset); wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); return Arrays.equals(wordBuf, ZipArchiveOutputStream.LFH_SIG); } /** * Searches the archive backwards from minDistance to maxDistance * for the given signature, positions the RandomaccessFile right * at the signature if it has been found. */ private boolean tryToLocateSignature(final long minDistanceFromEnd, final long maxDistanceFromEnd, final byte[] sig) throws IOException { boolean found = false; long off = archive.size() - minDistanceFromEnd; final long stopSearching = Math.max(0L, archive.size() - maxDistanceFromEnd); if (off >= 0) { for (; off >= stopSearching; off--) { archive.position(off); try { wordBbuf.rewind(); IOUtils.readFully(archive, wordBbuf); wordBbuf.flip(); } catch (final EOFException ex) { // NOSONAR break; } int curr = wordBbuf.get(); if (curr == sig[POS_0]) { curr = wordBbuf.get(); if (curr == sig[POS_1]) { curr = wordBbuf.get(); if (curr == sig[POS_2]) { curr = wordBbuf.get(); if (curr == sig[POS_3]) { found = true; break; } } } } } } if (found) { archive.position(off); } return found; } }




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