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Apache Commons Compress 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.
/*
* 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.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.EnumSet;
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.InflaterInputStream;
import java.util.zip.ZipException;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.commons.compress.utils.IOUtils;
import static org.apache.commons.compress.archivers.zip.ZipConstants.DWORD;
import static org.apache.commons.compress.archivers.zip.ZipConstants.SHORT;
import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD;
import static org.apache.commons.compress.archivers.zip.ZipConstants.ZIP64_MAGIC;
import static org.apache.commons.compress.archivers.zip.ZipConstants.ZIP64_MAGIC_SHORT;
/**
* Replacement for 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
* org.apache.commons.compress.archivers.zip.ZipArchiveEntry
* instead of java.util.zip.ZipEntry.
*
* It doesn't extend java.util.zip.ZipFile as it would
* have to reimplement all methods anyway. Like
* 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
* java.util.zip.ZipFile, with a couple of exceptions:
*
*
* - There is no getName method.
* - entries has been renamed to getEntries.
* - getEntries and getEntry return
*
org.apache.commons.compress.archivers.zip.ZipArchiveEntry
* instances.
* - close is allowed to throw IOException.
*
*
*/
public class ZipFile implements Closeable {
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;
/**
* 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);
private static final class OffsetEntry {
private long headerOffset = -1;
private long dataOffset = -1;
}
/**
* The encoding to use for filenames 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 filenames 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;
// cached buffers - must only be used locally in the class (COMPRESS-172 - reduce garbage collection)
private final byte[] dwordBuf = new byte[DWORD];
private final byte[] wordBuf = new byte[WORD];
private final byte[] cfhBuf = new byte[CFH_LEN];
private final byte[] shortBuf = new byte[SHORT];
private final ByteBuffer dwordBbuf = ByteBuffer.wrap(dwordBuf);
private final ByteBuffer wordBbuf = ByteBuffer.wrap(wordBuf);
private final ByteBuffer cfhBbuf = ByteBuffer.wrap(cfhBuf);
/**
* 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 "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), 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), encoding, true);
}
/**
* 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, 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(Files.newByteChannel(f.toPath(), EnumSet.of(StandardOpenOption.READ)),
f.getAbsolutePath(), encoding, useUnicodeExtraFields, true);
}
/**
* 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);
}
private ZipFile(final SeekableByteChannel channel, final String archiveName,
final String encoding, final boolean useUnicodeExtraFields,
final boolean closeOnError)
throws IOException {
this.archiveName = archiveName;
this.encoding = encoding;
this.zipEncoding = ZipEncodingHelper.getZipEncoding(encoding);
this.useUnicodeExtraFields = useUnicodeExtraFields;
archive = channel;
boolean success = false;
try {
final Map entriesWithoutUTF8Flag =
populateFromCentralDirectory();
resolveLocalFileHeaderData(entriesWithoutUTF8Flag);
success = true;
} finally {
closed = !success;
if (!success && closeOnError) {
IOUtils.closeQuietly(archive);
}
}
}
/**
* The encoding to use for filenames and the file comment.
*
* @return null if using the platform's default character encoding.
*/
public String getEncoding() {
return encoding;
}
/**
* 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();
}
/**
* close a zipfile quietly; throw no io fault, do nothing
* on a null parameter
* @param zipfile file to close, can be null
*/
public static void closeQuietly(final ZipFile zipfile) {
IOUtils.closeQuietly(zipfile);
}
/**
* Returns 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);
}
/**
* Returns 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(new ZipArchiveEntry[entries.size()]);
Arrays.sort(allEntries, offsetComparator);
return Collections.enumeration(Arrays.asList(allEntries));
}
/**
* Returns 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;
}
/**
* Returns 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();
}
/**
* Returns 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 = new ZipArchiveEntry[0];
if (nameMap.containsKey(name)) {
entriesOfThatName = nameMap.get(name).toArray(entriesOfThatName);
Arrays.sort(entriesOfThatName, offsetComparator);
}
return Arrays.asList(entriesOfThatName);
}
/**
* 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);
}
/**
* Expose 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.
*
* @param ze The entry to get the stream for
* @return The raw input stream containing (possibly) compressed data.
* @since 1.11
*/
public InputStream getRawInputStream(final ZipArchiveEntry ze) {
if (!(ze instanceof Entry)) {
return null;
}
final OffsetEntry offsetEntry = ((Entry) ze).getOffsetEntry();
final long start = offsetEntry.dataOffset;
return new BoundedInputStream(start, ze.getCompressedSize());
}
/**
* Transfer selected entries from this zipfile 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));
}
}
}
/**
* Returns an InputStream for reading the contents of the given entry.
*
* @param ze the entry to get the stream for.
* @return a stream to read the entry from.
* @throws IOException if unable to create an input stream from the zipentry
* @throws ZipException if the zipentry uses an unsupported feature
*/
public InputStream getInputStream(final ZipArchiveEntry ze)
throws IOException, ZipException {
if (!(ze instanceof Entry)) {
return null;
}
// cast valididty is checked just above
final OffsetEntry offsetEntry = ((Entry) ze).getOffsetEntry();
ZipUtil.checkRequestedFeatures(ze);
final long start = offsetEntry.dataOffset;
// doesn't get closed if the method is not supported, but doesn't hold any resources either
final BoundedInputStream bis =
new BoundedInputStream(start, ze.getCompressedSize()); //NOSONAR
switch (ZipMethod.getMethodByCode(ze.getMethod())) {
case STORED:
return bis;
case UNSHRINKING:
return new UnshrinkingInputStream(bis);
case IMPLODING:
return new ExplodingInputStream(ze.getGeneralPurposeBit().getSlidingDictionarySize(),
ze.getGeneralPurposeBit().getNumberOfShannonFanoTrees(), new BufferedInputStream(bis));
case DEFLATED:
bis.addDummy();
final Inflater inflater = new Inflater(true);
return new InflaterInputStream(bis, inflater) {
@Override
public void close() throws IOException {
try {
super.close();
} finally {
inflater.end();
}
}
};
case BZIP2:
return new BZip2CompressorInputStream(bis);
case AES_ENCRYPTED:
case ENHANCED_DEFLATED:
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:
default:
throw new ZipException("Found unsupported compression method "
+ ze.getMethod());
}
}
/**
*
* Convenience method to return 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;
}
/**
* Ensures that the close method of this zipfile is called when
* there are no more references to it.
* @see #close()
*/
@Override
protected void finalize() throws Throwable {
try {
if (!closed) {
System.err.println("Cleaning up unclosed ZipFile for archive "
+ archiveName);
close();
}
} finally {
super.finalize();
}
}
/**
* Length of a "central directory" entry structure without file
* name, extra fields or comment.
*/
private static final int CFH_LEN =
/* version made by */ SHORT
/* version needed to extract */ + SHORT
/* general purpose bit flag */ + SHORT
/* compression method */ + SHORT
/* last mod file time */ + SHORT
/* last mod file date */ + SHORT
/* crc-32 */ + WORD
/* compressed size */ + WORD
/* uncompressed size */ + WORD
/* filename length */ + SHORT
/* extra field length */ + SHORT
/* file comment length */ + SHORT
/* disk number start */ + SHORT
/* internal file attributes */ + SHORT
/* external file attributes */ + WORD
/* relative offset of local header */ + WORD;
private static final long CFH_SIG =
ZipLong.getValue(ZipArchiveOutputStream.CFH_SIG);
/**
* 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();
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;
}
/**
* 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 OffsetEntry offset = new OffsetEntry();
final Entry ze = new Entry(offset);
final int versionMadeBy = ZipShort.getValue(cfhBuf, off);
off += SHORT;
ze.setVersionMadeBy(versionMadeBy);
ze.setPlatform((versionMadeBy >> BYTE_SHIFT) & NIBLET_MASK);
ze.setVersionRequired(ZipShort.getValue(cfhBuf, off));
off += SHORT; // version required
final GeneralPurposeBit gpFlag = GeneralPurposeBit.parse(cfhBuf, off);
final boolean hasUTF8Flag = gpFlag.usesUTF8ForNames();
final ZipEncoding entryEncoding =
hasUTF8Flag ? ZipEncodingHelper.UTF8_ZIP_ENCODING : zipEncoding;
ze.setGeneralPurposeBit(gpFlag);
ze.setRawFlag(ZipShort.getValue(cfhBuf, off));
off += SHORT;
//noinspection MagicConstant
ze.setMethod(ZipShort.getValue(cfhBuf, off));
off += SHORT;
final long time = ZipUtil.dosToJavaTime(ZipLong.getValue(cfhBuf, off));
ze.setTime(time);
off += WORD;
ze.setCrc(ZipLong.getValue(cfhBuf, off));
off += WORD;
ze.setCompressedSize(ZipLong.getValue(cfhBuf, off));
off += WORD;
ze.setSize(ZipLong.getValue(cfhBuf, off));
off += WORD;
final int fileNameLen = ZipShort.getValue(cfhBuf, off);
off += SHORT;
final int extraLen = ZipShort.getValue(cfhBuf, off);
off += SHORT;
final int commentLen = ZipShort.getValue(cfhBuf, off);
off += SHORT;
final int diskStart = ZipShort.getValue(cfhBuf, off);
off += SHORT;
ze.setInternalAttributes(ZipShort.getValue(cfhBuf, off));
off += SHORT;
ze.setExternalAttributes(ZipLong.getValue(cfhBuf, off));
off += WORD;
final byte[] fileName = new byte[fileNameLen];
IOUtils.readFully(archive, ByteBuffer.wrap(fileName));
ze.setName(entryEncoding.decode(fileName), fileName);
// LFH offset,
offset.headerOffset = ZipLong.getValue(cfhBuf, off);
// data offset will be filled later
entries.add(ze);
final byte[] cdExtraData = new byte[extraLen];
IOUtils.readFully(archive, ByteBuffer.wrap(cdExtraData));
ze.setCentralDirectoryExtra(cdExtraData);
setSizesAndOffsetFromZip64Extra(ze, offset, diskStart);
final byte[] comment = new byte[commentLen];
IOUtils.readFully(archive, ByteBuffer.wrap(comment));
ze.setComment(entryEncoding.decode(comment));
if (!hasUTF8Flag && useUnicodeExtraFields) {
noUTF8Flag.put(ze, new NameAndComment(fileName, comment));
}
}
/**
* 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,
final OffsetEntry offset,
final int diskStart)
throws IOException {
final Zip64ExtendedInformationExtraField z64 =
(Zip64ExtendedInformationExtraField)
ze.getExtraField(Zip64ExtendedInformationExtraField.HEADER_ID);
if (z64 != null) {
final boolean hasUncompressedSize = ze.getSize() == ZIP64_MAGIC;
final boolean hasCompressedSize = ze.getCompressedSize() == ZIP64_MAGIC;
final boolean hasRelativeHeaderOffset =
offset.headerOffset == ZIP64_MAGIC;
z64.reparseCentralDirectoryData(hasUncompressedSize,
hasCompressedSize,
hasRelativeHeaderOffset,
diskStart == ZIP64_MAGIC_SHORT);
if (hasUncompressedSize) {
ze.setSize(z64.getSize().getLongValue());
} else if (hasCompressedSize) {
z64.setSize(new ZipEightByteInteger(ze.getSize()));
}
if (hasCompressedSize) {
ze.setCompressedSize(z64.getCompressedSize().getLongValue());
} else if (hasUncompressedSize) {
z64.setCompressedSize(new ZipEightByteInteger(ze.getCompressedSize()));
}
if (hasRelativeHeaderOffset) {
offset.headerOffset =
z64.getRelativeHeaderOffset().getLongValue();
}
}
}
/**
* 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 */ WORD
/* number of this disk */ + SHORT
/* number of the disk with the */
/* start of the central directory */ + SHORT
/* total number of entries in */
/* the central dir on this disk */ + SHORT
/* total number of entries in */
/* the central dir */ + SHORT
/* size of the central directory */ + WORD
/* offset of start of central */
/* directory with respect to */
/* the starting disk number */ + WORD
/* zipfile comment length */ + 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 zipfile comment */ + ZIP64_MAGIC_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 start of the "End of central directory
* record".
*/
private static final int CFD_LOCATOR_OFFSET =
/* end of central dir signature */ WORD
/* number of this disk */ + SHORT
/* number of the disk with the */
/* start of the central directory */ + SHORT
/* total number of entries in */
/* the central dir on this disk */ + SHORT
/* total number of entries in */
/* the central dir */ + SHORT
/* size of the central directory */ + 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 */ WORD
/* number of the disk with the start */
/* start of the zip64 end of */
/* central directory */ + WORD
/* relative offset of the zip64 */
/* end of central directory record */ + DWORD
/* total number of disks */ + 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 */ WORD
/* number of the disk with the start */
/* start of the zip64 end of */
/* central directory */ + 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 */ WORD
/* size of zip64 end of central */
/* directory record */ + DWORD
/* version made by */ + SHORT
/* version needed to extract */ + SHORT
/* number of this disk */ + WORD
/* number of the disk with the */
/* start of the central directory */ + WORD
/* total number of entries in the */
/* central directory on this disk */ + DWORD
/* total number of entries in the */
/* central directory */ + DWORD
/* size of the central directory */ + DWORD;
/**
* 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 - WORD);
}
positionAtCentralDirectory32();
} else {
positionAtCentralDirectory64();
}
}
/**
* 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 {
skipBytes(ZIP64_EOCDL_LOCATOR_OFFSET
- 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.");
}
skipBytes(ZIP64_EOCD_CFD_LOCATOR_OFFSET
- WORD /* signature has already been read */);
dwordBbuf.rewind();
IOUtils.readFully(archive, dwordBbuf);
archive.position(ZipEightByteInteger.getLongValue(dwordBuf));
}
/**
* 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 {
skipBytes(CFD_LOCATOR_OFFSET);
wordBbuf.rewind();
IOUtils.readFully(archive, wordBbuf);
archive.position(ZipLong.getValue(wordBuf));
}
/**
* 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");
}
}
/**
* 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 (EOFException ex) {
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;
}
/**
* Skips the given number of bytes or throws an EOFException if
* skipping failed.
*/
private void skipBytes(final int count) throws IOException {
long currentPosition = archive.position();
long newPosition = currentPosition + count;
if (newPosition > archive.size()) {
throw new EOFException();
}
archive.position(newPosition);
}
/**
* Number of bytes in local file header up to the "length of
* filename" entry.
*/
private static final long LFH_OFFSET_FOR_FILENAME_LENGTH =
/* local file header signature */ WORD
/* version needed to extract */ + SHORT
/* general purpose bit flag */ + SHORT
/* compression method */ + SHORT
/* last mod file time */ + SHORT
/* last mod file date */ + SHORT
/* crc-32 */ + WORD
/* compressed size */ + WORD
/* uncompressed size */ + (long) WORD;
/**
* 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 OffsetEntry offsetEntry = ze.getOffsetEntry();
final long offset = offsetEntry.headerOffset;
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);
skipBytes(fileNameLen);
final byte[] localExtraData = new byte[extraFieldLen];
IOUtils.readFully(archive, ByteBuffer.wrap(localExtraData));
ze.setExtra(localExtraData);
offsetEntry.dataOffset = offset + LFH_OFFSET_FOR_FILENAME_LENGTH
+ SHORT + SHORT + fileNameLen + extraFieldLen;
if (entriesWithoutUTF8Flag.containsKey(ze)) {
final NameAndComment nc = entriesWithoutUTF8Flag.get(ze);
ZipUtil.setNameAndCommentFromExtraFields(ze, nc.name,
nc.comment);
}
final String name = ze.getName();
LinkedList entriesOfThatName = nameMap.get(name);
if (entriesOfThatName == null) {
entriesOfThatName = new LinkedList<>();
nameMap.put(name, entriesOfThatName);
}
entriesOfThatName.addLast(ze);
}
}
/**
* 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(0);
wordBbuf.rewind();
IOUtils.readFully(archive, wordBbuf);
return Arrays.equals(wordBuf, ZipArchiveOutputStream.LFH_SIG);
}
/**
* InputStream that delegates requests to the underlying
* SeekableByteChannel, making sure that only bytes from a certain
* range can be read.
*/
private class BoundedInputStream extends InputStream {
private static final int MAX_BUF_LEN = 8192;
private final ByteBuffer buffer;
private long remaining;
private long loc;
private boolean addDummyByte = false;
BoundedInputStream(final long start, final long remaining) {
this.remaining = remaining;
loc = start;
if (remaining < MAX_BUF_LEN && remaining > 0) {
buffer = ByteBuffer.allocate((int) remaining);
} else {
buffer = ByteBuffer.allocate(MAX_BUF_LEN);
}
}
@Override
public int read() throws IOException {
if (remaining-- <= 0) {
if (addDummyByte) {
addDummyByte = false;
return 0;
}
return -1;
}
synchronized (archive) {
archive.position(loc++);
int read = read(1);
if (read < 0) {
return read;
}
return buffer.get() & 0xff;
}
}
@Override
public int read(final byte[] b, final int off, int len) throws IOException {
if (remaining <= 0) {
if (addDummyByte) {
addDummyByte = false;
b[off] = 0;
return 1;
}
return -1;
}
if (len <= 0) {
return 0;
}
if (len > remaining) {
len = (int) remaining;
}
ByteBuffer buf;
int ret = -1;
synchronized (archive) {
archive.position(loc);
if (len <= buffer.capacity()) {
buf = buffer;
ret = read(len);
} else {
buf = ByteBuffer.allocate(len);
ret = archive.read(buf);
buf.flip();
}
}
if (ret > 0) {
buf.get(b, off, ret);
loc += ret;
remaining -= ret;
}
return ret;
}
private int read(int len) throws IOException {
buffer.rewind().limit(len);
int read = archive.read(buffer);
buffer.flip();
return read;
}
/**
* Inflater needs an extra dummy byte for nowrap - see
* Inflater's javadocs.
*/
void addDummy() {
addDummyByte = true;
}
}
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;
}
}
/**
* 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 final Comparator offsetComparator =
new Comparator() {
@Override
public int compare(final ZipArchiveEntry e1, final ZipArchiveEntry e2) {
if (e1 == e2) {
return 0;
}
final Entry ent1 = e1 instanceof Entry ? (Entry) e1 : null;
final Entry ent2 = e2 instanceof Entry ? (Entry) e2 : null;
if (ent1 == null) {
return 1;
}
if (ent2 == null) {
return -1;
}
final long val = (ent1.getOffsetEntry().headerOffset
- ent2.getOffsetEntry().headerOffset);
return val == 0 ? 0 : val < 0 ? -1 : +1;
}
};
/**
* Extends ZipArchiveEntry to store the offset within the archive.
*/
private static class Entry extends ZipArchiveEntry {
private final OffsetEntry offsetEntry;
Entry(final OffsetEntry offset) {
this.offsetEntry = offset;
}
OffsetEntry getOffsetEntry() {
return offsetEntry;
}
@Override
public int hashCode() {
return 3 * super.hashCode()
+ (int) (offsetEntry.headerOffset % Integer.MAX_VALUE);
}
@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 offsetEntry.headerOffset
== otherEntry.offsetEntry.headerOffset
&& offsetEntry.dataOffset
== otherEntry.offsetEntry.dataOffset;
}
return false;
}
}
}
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