org.apache.commons.compress.archivers.zip.ZipFile Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of commons-compress Show documentation
Show all versions of commons-compress Show documentation
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.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
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 RandomAccessFile 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 {
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;
/**
* Maps ZipArchiveEntrys to two longs, recording the offsets of
* the local file headers and the start of entry data.
*/
private final Map entries =
new LinkedHashMap(HASH_SIZE);
/**
* Maps String to ZipArchiveEntrys, name -> actual entry.
*/
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 RandomAccessFile archive;
/**
* Whether to look for and use Unicode extra fields.
*/
private final boolean useUnicodeExtraFields;
/**
* Whether the file is closed.
*/
private boolean closed;
// cached buffers - must only be used locally in the class (COMPRESS-172 - reduce garbage collection)
private final byte[] DWORD_BUF = new byte[DWORD];
private final byte[] WORD_BUF = new byte[WORD];
private final byte[] CFH_BUF = new byte[CFH_LEN];
private final byte[] SHORT_BUF = new byte[SHORT];
/**
* 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(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(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(String name, 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(File f, 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(File f, String encoding, boolean useUnicodeExtraFields)
throws IOException {
this.archiveName = f.getAbsolutePath();
this.encoding = encoding;
this.zipEncoding = ZipEncodingHelper.getZipEncoding(encoding);
this.useUnicodeExtraFields = useUnicodeExtraFields;
archive = new RandomAccessFile(f, "r");
boolean success = false;
try {
Map entriesWithoutUTF8Flag =
populateFromCentralDirectory();
resolveLocalFileHeaderData(entriesWithoutUTF8Flag);
success = true;
} finally {
if (!success) {
try {
closed = true;
archive.close();
} catch (IOException e2) { // NOPMD
// swallow, throw the original exception instead
}
}
}
}
/**
* 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.
*/
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(ZipFile zipfile) {
if (zipfile != null) {
try {
zipfile.close();
} catch (IOException e) { // NOPMD
//ignore, that's why the method is called "quietly"
}
}
}
/**
* 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.keySet());
}
/**
* 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 Commons Compress 1.1
*/
public Enumeration getEntriesInPhysicalOrder() {
ZipArchiveEntry[] allEntries =
entries.keySet().toArray(new ZipArchiveEntry[0]);
Arrays.sort(allEntries, OFFSET_COMPARATOR);
return Collections.enumeration(Arrays.asList(allEntries));
}
/**
* Returns a named entry - or {@code null} if no entry by
* that name exists.
* @param name name of the entry.
* @return the ZipArchiveEntry corresponding to the given name - or
* {@code null} if not present.
*/
public ZipArchiveEntry getEntry(String name) {
return nameMap.get(name);
}
/**
* 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
*/
public boolean canReadEntryData(ZipArchiveEntry ze) {
return ZipUtil.canHandleEntryData(ze);
}
/**
* 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(ZipArchiveEntry ze)
throws IOException, ZipException {
OffsetEntry offsetEntry = entries.get(ze);
if (offsetEntry == null) {
return null;
}
ZipUtil.checkRequestedFeatures(ze);
long start = offsetEntry.dataOffset;
BoundedInputStream bis =
new BoundedInputStream(start, ze.getCompressedSize());
switch (ze.getMethod()) {
case ZipEntry.STORED:
return bis;
case ZipEntry.DEFLATED:
bis.addDummy();
final Inflater inflater = new Inflater(true);
return new InflaterInputStream(bis, inflater) {
@Override
public void close() throws IOException {
super.close();
inflater.end();
}
};
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(ZipArchiveEntry entry) throws IOException {
if (entry != null && entry.isUnixSymlink()) {
InputStream in = null;
try {
in = getInputStream(entry);
byte[] symlinkBytes = IOUtils.toByteArray(in);
return zipEncoding.decode(symlinkBytes);
} finally {
if (in != null) {
in.close();
}
}
} else {
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 {
HashMap noUTF8Flag =
new HashMap();
positionAtCentralDirectory();
archive.readFully(WORD_BUF);
long sig = ZipLong.getValue(WORD_BUF);
if (sig != CFH_SIG && startsWithLocalFileHeader()) {
throw new IOException("central directory is empty, can't expand"
+ " corrupt archive.");
}
while (sig == CFH_SIG) {
readCentralDirectoryEntry(noUTF8Flag);
archive.readFully(WORD_BUF);
sig = ZipLong.getValue(WORD_BUF);
}
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(Map noUTF8Flag)
throws IOException {
archive.readFully(CFH_BUF);
int off = 0;
ZipArchiveEntry ze = new ZipArchiveEntry();
int versionMadeBy = ZipShort.getValue(CFH_BUF, off);
off += SHORT;
ze.setPlatform((versionMadeBy >> BYTE_SHIFT) & NIBLET_MASK);
off += SHORT; // skip version info
final GeneralPurposeBit gpFlag = GeneralPurposeBit.parse(CFH_BUF, off);
final boolean hasUTF8Flag = gpFlag.usesUTF8ForNames();
final ZipEncoding entryEncoding =
hasUTF8Flag ? ZipEncodingHelper.UTF8_ZIP_ENCODING : zipEncoding;
ze.setGeneralPurposeBit(gpFlag);
off += SHORT;
ze.setMethod(ZipShort.getValue(CFH_BUF, off));
off += SHORT;
long time = ZipUtil.dosToJavaTime(ZipLong.getValue(CFH_BUF, off));
ze.setTime(time);
off += WORD;
ze.setCrc(ZipLong.getValue(CFH_BUF, off));
off += WORD;
ze.setCompressedSize(ZipLong.getValue(CFH_BUF, off));
off += WORD;
ze.setSize(ZipLong.getValue(CFH_BUF, off));
off += WORD;
int fileNameLen = ZipShort.getValue(CFH_BUF, off);
off += SHORT;
int extraLen = ZipShort.getValue(CFH_BUF, off);
off += SHORT;
int commentLen = ZipShort.getValue(CFH_BUF, off);
off += SHORT;
int diskStart = ZipShort.getValue(CFH_BUF, off);
off += SHORT;
ze.setInternalAttributes(ZipShort.getValue(CFH_BUF, off));
off += SHORT;
ze.setExternalAttributes(ZipLong.getValue(CFH_BUF, off));
off += WORD;
byte[] fileName = new byte[fileNameLen];
archive.readFully(fileName);
ze.setName(entryEncoding.decode(fileName), fileName);
// LFH offset,
OffsetEntry offset = new OffsetEntry();
offset.headerOffset = ZipLong.getValue(CFH_BUF, off);
// data offset will be filled later
entries.put(ze, offset);
nameMap.put(ze.getName(), ze);
byte[] cdExtraData = new byte[extraLen];
archive.readFully(cdExtraData);
ze.setCentralDirectoryExtra(cdExtraData);
setSizesAndOffsetFromZip64Extra(ze, offset, diskStart);
byte[] comment = new byte[commentLen];
archive.readFully(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(ZipArchiveEntry ze,
OffsetEntry offset,
int diskStart)
throws IOException {
Zip64ExtendedInformationExtraField z64 =
(Zip64ExtendedInformationExtraField)
ze.getExtraField(Zip64ExtendedInformationExtraField.HEADER_ID);
if (z64 != null) {
boolean hasUncompressedSize = ze.getSize() == ZIP64_MAGIC;
boolean hasCompressedSize = ze.getCompressedSize() == ZIP64_MAGIC;
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;
boolean searchedForZip64EOCD =
archive.getFilePointer() > ZIP64_EOCDL_LENGTH;
if (searchedForZip64EOCD) {
archive.seek(archive.getFilePointer() - ZIP64_EOCDL_LENGTH);
archive.readFully(WORD_BUF);
found = Arrays.equals(ZipArchiveOutputStream.ZIP64_EOCD_LOC_SIG,
WORD_BUF);
}
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 */);
archive.readFully(DWORD_BUF);
archive.seek(ZipEightByteInteger.getLongValue(DWORD_BUF));
archive.readFully(WORD_BUF);
if (!Arrays.equals(WORD_BUF, 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 */);
archive.readFully(DWORD_BUF);
archive.seek(ZipEightByteInteger.getLongValue(DWORD_BUF));
}
/**
* 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);
archive.readFully(WORD_BUF);
archive.seek(ZipLong.getValue(WORD_BUF));
}
/**
* Searches for the and positions the stream at the start of the
* "End of central dir record".
*/
private void positionAtEndOfCentralDirectoryRecord()
throws IOException {
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(long minDistanceFromEnd,
long maxDistanceFromEnd,
byte[] sig) throws IOException {
boolean found = false;
long off = archive.length() - minDistanceFromEnd;
final long stopSearching =
Math.max(0L, archive.length() - maxDistanceFromEnd);
if (off >= 0) {
for (; off >= stopSearching; off--) {
archive.seek(off);
int curr = archive.read();
if (curr == -1) {
break;
}
if (curr == sig[POS_0]) {
curr = archive.read();
if (curr == sig[POS_1]) {
curr = archive.read();
if (curr == sig[POS_2]) {
curr = archive.read();
if (curr == sig[POS_3]) {
found = true;
break;
}
}
}
}
}
}
if (found) {
archive.seek(off);
}
return found;
}
/**
* Skips the given number of bytes or throws an EOFException if
* skipping failed.
*/
private void skipBytes(final int count) throws IOException {
int totalSkipped = 0;
while (totalSkipped < count) {
int skippedNow = archive.skipBytes(count - totalSkipped);
if (skippedNow <= 0) {
throw new EOFException();
}
totalSkipped += skippedNow;
}
}
/**
* 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 */ + 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(Map
entriesWithoutUTF8Flag)
throws IOException {
// changing the name of a ZipArchiveEntry is going to change
// the hashcode - see COMPRESS-164
// Map needs to be reconstructed in order to keep central
// directory order
Map origMap =
new LinkedHashMap(entries);
entries.clear();
for (Map.Entry ent : origMap.entrySet()) {
ZipArchiveEntry ze = ent.getKey();
OffsetEntry offsetEntry = ent.getValue();
long offset = offsetEntry.headerOffset;
archive.seek(offset + LFH_OFFSET_FOR_FILENAME_LENGTH);
archive.readFully(SHORT_BUF);
int fileNameLen = ZipShort.getValue(SHORT_BUF);
archive.readFully(SHORT_BUF);
int extraFieldLen = ZipShort.getValue(SHORT_BUF);
int lenToSkip = fileNameLen;
while (lenToSkip > 0) {
int skipped = archive.skipBytes(lenToSkip);
if (skipped <= 0) {
throw new IOException("failed to skip file name in"
+ " local file header");
}
lenToSkip -= skipped;
}
byte[] localExtraData = new byte[extraFieldLen];
archive.readFully(localExtraData);
ze.setExtra(localExtraData);
offsetEntry.dataOffset = offset + LFH_OFFSET_FOR_FILENAME_LENGTH
+ SHORT + SHORT + fileNameLen + extraFieldLen;
if (entriesWithoutUTF8Flag.containsKey(ze)) {
String orig = ze.getName();
NameAndComment nc = entriesWithoutUTF8Flag.get(ze);
ZipUtil.setNameAndCommentFromExtraFields(ze, nc.name,
nc.comment);
if (!orig.equals(ze.getName())) {
nameMap.remove(orig);
nameMap.put(ze.getName(), ze);
}
}
entries.put(ze, offsetEntry);
}
}
/**
* Checks whether the archive starts with a LFH. If it doesn't,
* it may be an empty archive.
*/
private boolean startsWithLocalFileHeader() throws IOException {
archive.seek(0);
archive.readFully(WORD_BUF);
return Arrays.equals(WORD_BUF, ZipArchiveOutputStream.LFH_SIG);
}
/**
* InputStream that delegates requests to the underlying
* RandomAccessFile, making sure that only bytes from a certain
* range can be read.
*/
private class BoundedInputStream extends InputStream {
private long remaining;
private long loc;
private boolean addDummyByte = false;
BoundedInputStream(long start, long remaining) {
this.remaining = remaining;
loc = start;
}
@Override
public int read() throws IOException {
if (remaining-- <= 0) {
if (addDummyByte) {
addDummyByte = false;
return 0;
}
return -1;
}
synchronized (archive) {
archive.seek(loc++);
return archive.read();
}
}
@Override
public int read(byte[] b, 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;
}
int ret = -1;
synchronized (archive) {
archive.seek(loc);
ret = archive.read(b, off, len);
}
if (ret > 0) {
loc += ret;
remaining -= ret;
}
return ret;
}
/**
* 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(byte[] name, 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 Commons Compress 1.1
*/
private final Comparator OFFSET_COMPARATOR =
new Comparator() {
public int compare(ZipArchiveEntry e1, ZipArchiveEntry e2) {
if (e1 == e2) {
return 0;
}
OffsetEntry off1 = entries.get(e1);
OffsetEntry off2 = entries.get(e2);
if (off1 == null) {
return 1;
}
if (off2 == null) {
return -1;
}
long val = (off1.headerOffset - off2.headerOffset);
return val == 0 ? 0 : val < 0 ? -1 : +1;
}
};
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy