com.github.rapidark.preloader.zip.ZipFile Maven / Gradle / Ivy
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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 com.github.rapidark.preloader.zip;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.zip.CRC32;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
import java.util.zip.ZipException;
/**
* 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.tools.zip.ZipEntry 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.
*
* 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.tools.zip.ZipEntry instances.
* - close is allowed to throw IOException.
*
*
*/
public class ZipFile {
private static final int HASH_SIZE = 509;
private static final int SHORT = 2;
private static final int WORD = 4;
private static final int NIBLET_MASK = 0x0f;
private 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 ZipEntrys to Longs, recording the offsets of the local
* file headers.
*/
private final Map entries = new HashMap(HASH_SIZE);
/**
* Maps String to ZipEntrys, 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 the platform's default character encoding.
*/
private String encoding = null;
/**
* The zip encoding to use for filenames and the file comment.
*/
private final ZipEncoding zipEncoding;
/**
* The actual data source.
*/
private RandomAccessFile archive;
/**
* Whether to look for and use Unicode extra fields.
*/
private final boolean useUnicodeExtraFields;
/**
* Opens the given file for reading, assuming the platform's
* native encoding 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, null);
}
/**
* Opens the given file for reading, assuming the platform's
* native encoding for file names.
*
* @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), null);
}
/**
* 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
*
* @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.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 {
archive.close();
} catch (IOException e2) {
// 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 {
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) {
//ignore
}
}
}
/**
* Returns all entries.
* @return all entries as {@link ZipEntry} instances
*/
public Enumeration getEntries() {
return Collections.enumeration(entries.keySet());
}
/**
* Returns a named entry - or null if no entry by
* that name exists.
* @param name name of the entry.
* @return the ZipEntry corresponding to the given name - or
* null if not present.
*/
public ZipEntry getEntry(String name) {
return (ZipEntry) nameMap.get(name);
}
/**
* 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 zipenty
* @throws ZipException if the zipentry has an unsupported
* compression method
*/
public InputStream getInputStream(ZipEntry ze)
throws IOException, ZipException {
OffsetEntry offsetEntry = (OffsetEntry) entries.get(ze);
if (offsetEntry == null) {
return null;
}
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) {
public void close() throws IOException {
super.close();
inflater.end();
}
};
default:
throw new ZipException("Found unsupported compression method "
+ ze.getMethod());
}
}
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;
/**
* Reads the central directory of the given archive and populates
* the internal tables with ZipEntry instances.
*
* The ZipEntrys 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<ZipEntry, NameAndComment>> of
* zipentries that didn't have the language encoding flag set when
* read.
*/
private Map populateFromCentralDirectory()
throws IOException {
HashMap noUTF8Flag = new HashMap();
positionAtCentralDirectory();
byte[] cfh = new byte[CFH_LEN];
byte[] signatureBytes = new byte[WORD];
archive.readFully(signatureBytes);
long sig = ZipLong.getValue(signatureBytes);
final long cfhSig = ZipLong.getValue(ZipOutputStream.CFH_SIG);
if (sig != cfhSig && startsWithLocalFileHeader()) {
throw new IOException("central directory is empty, can't expand"
+ " corrupt archive.");
}
while (sig == cfhSig) {
archive.readFully(cfh);
int off = 0;
ZipEntry ze = new ZipEntry();
int versionMadeBy = ZipShort.getValue(cfh, off);
off += SHORT;
ze.setPlatform((versionMadeBy >> BYTE_SHIFT) & NIBLET_MASK);
off += SHORT; // skip version info
final int generalPurposeFlag = ZipShort.getValue(cfh, off);
final boolean hasUTF8Flag =
(generalPurposeFlag & ZipOutputStream.UFT8_NAMES_FLAG) != 0;
final ZipEncoding entryEncoding =
hasUTF8Flag ? ZipEncodingHelper.UTF8_ZIP_ENCODING : zipEncoding;
off += SHORT;
ze.setMethod(ZipShort.getValue(cfh, off));
off += SHORT;
// FIXME this is actually not very cpu cycles friendly as we are converting from
// dos to java while the underlying Sun implementation will convert
// from java to dos time for internal storage...
long time = dosToJavaTime(ZipLong.getValue(cfh, off));
ze.setTime(time);
off += WORD;
ze.setCrc(ZipLong.getValue(cfh, off));
off += WORD;
ze.setCompressedSize(ZipLong.getValue(cfh, off));
off += WORD;
ze.setSize(ZipLong.getValue(cfh, off));
off += WORD;
int fileNameLen = ZipShort.getValue(cfh, off);
off += SHORT;
int extraLen = ZipShort.getValue(cfh, off);
off += SHORT;
int commentLen = ZipShort.getValue(cfh, off);
off += SHORT;
off += SHORT; // disk number
ze.setInternalAttributes(ZipShort.getValue(cfh, off));
off += SHORT;
ze.setExternalAttributes(ZipLong.getValue(cfh, off));
off += WORD;
byte[] fileName = new byte[fileNameLen];
archive.readFully(fileName);
ze.setName(entryEncoding.decode(fileName));
// LFH offset,
OffsetEntry offset = new OffsetEntry();
offset.headerOffset = ZipLong.getValue(cfh, 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);
byte[] comment = new byte[commentLen];
archive.readFully(comment);
ze.setComment(entryEncoding.decode(comment));
archive.readFully(signatureBytes);
sig = ZipLong.getValue(signatureBytes);
if (!hasUTF8Flag && useUnicodeExtraFields) {
noUTF8Flag.put(ze, new NameAndComment(fileName, comment));
}
}
return noUTF8Flag;
}
private 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;
private static final int MAX_EOCD_SIZE = MIN_EOCD_SIZE
/* maximum length of zipfile comment */ + 0xFFFF;
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;
/**
* Searches for the "End of central dir record", parses
* it and positions the stream at the first central directory
* record.
*/
private void positionAtCentralDirectory()
throws IOException {
boolean found = false;
long off = archive.length() - MIN_EOCD_SIZE;
final long stopSearching =
Math.max(0L, archive.length() - MAX_EOCD_SIZE);
if (off >= 0) {
final byte[] sig = ZipOutputStream.EOCD_SIG;
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) {
throw new ZipException("archive is not a ZIP archive");
}
archive.seek(off + CFD_LOCATOR_OFFSET);
byte[] cfdOffset = new byte[WORD];
archive.readFully(cfdOffset);
archive.seek(ZipLong.getValue(cfdOffset));
}
/**
* 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 {
Enumeration e = Collections.enumeration(new HashSet(entries.keySet()));
while (e.hasMoreElements()) {
ZipEntry ze = (ZipEntry) e.nextElement();
OffsetEntry offsetEntry = (OffsetEntry) entries.get(ze);
long offset = offsetEntry.headerOffset;
archive.seek(offset + LFH_OFFSET_FOR_FILENAME_LENGTH);
byte[] b = new byte[SHORT];
archive.readFully(b);
int fileNameLen = ZipShort.getValue(b);
archive.readFully(b);
int extraFieldLen = ZipShort.getValue(b);
int lenToSkip = fileNameLen;
while (lenToSkip > 0) {
int skipped = archive.skipBytes(lenToSkip);
if (skipped <= 0) {
throw new RuntimeException("failed to skip file name in"
+ " local file header");
}
lenToSkip -= skipped;
}
byte[] localExtraData = new byte[extraFieldLen];
archive.readFully(localExtraData);
ze.setExtra(localExtraData);
/*dataOffsets.put(ze,
new Long(offset + LFH_OFFSET_FOR_FILENAME_LENGTH
+ SHORT + SHORT + fileNameLen + extraFieldLen));
*/
offsetEntry.dataOffset = offset + LFH_OFFSET_FOR_FILENAME_LENGTH
+ SHORT + SHORT + fileNameLen + extraFieldLen;
if (entriesWithoutUTF8Flag.containsKey(ze)) {
// changing the name of a ZipEntry is going to change
// the hashcode
// - see https://issues.apache.org/jira/browse/COMPRESS-164
entries.remove(ze);
setNameAndCommentFromExtraFields(ze,
(NameAndComment)
entriesWithoutUTF8Flag.get(ze));
entries.put(ze, offsetEntry);
}
}
}
/**
* Convert a DOS date/time field to a Date object.
*
* @param zipDosTime contains the stored DOS time.
* @return a Date instance corresponding to the given time.
*/
protected static Date fromDosTime(ZipLong zipDosTime) {
long dosTime = zipDosTime.getValue();
return new Date(dosToJavaTime(dosTime));
}
/*
* Converts DOS time to Java time (number of milliseconds since epoch).
*/
private static long dosToJavaTime(long dosTime) {
Calendar cal = Calendar.getInstance();
// CheckStyle:MagicNumberCheck OFF - no point
cal.set(Calendar.YEAR, (int) ((dosTime >> 25) & 0x7f) + 1980);
cal.set(Calendar.MONTH, (int) ((dosTime >> 21) & 0x0f) - 1);
cal.set(Calendar.DATE, (int) (dosTime >> 16) & 0x1f);
cal.set(Calendar.HOUR_OF_DAY, (int) (dosTime >> 11) & 0x1f);
cal.set(Calendar.MINUTE, (int) (dosTime >> 5) & 0x3f);
cal.set(Calendar.SECOND, (int) (dosTime << 1) & 0x3e);
// CheckStyle:MagicNumberCheck ON
return cal.getTime().getTime();
}
/**
* Retrieve a String from the given bytes using the encoding set
* for this ZipFile.
*
* @param bytes the byte array to transform
* @return String obtained by using the given encoding
* @throws ZipException if the encoding cannot be recognized.
*/
protected String getString(byte[] bytes) throws ZipException {
try {
return ZipEncodingHelper.getZipEncoding(encoding).decode(bytes);
} catch (IOException ex) {
throw new ZipException("Failed to decode name: " + ex.getMessage());
}
}
/**
* 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);
final byte[] start = new byte[WORD];
archive.readFully(start);
for (int i = 0; i < start.length; i++) {
if (start[i] != ZipOutputStream.LFH_SIG[i]) {
return false;
}
}
return true;
}
/**
* If the entry has Unicode*ExtraFields and the CRCs of the
* names/comments match those of the extra fields, transfer the
* known Unicode values from the extra field.
*/
private void setNameAndCommentFromExtraFields(ZipEntry ze,
NameAndComment nc) {
UnicodePathExtraField name = (UnicodePathExtraField)
ze.getExtraField(UnicodePathExtraField.UPATH_ID);
String originalName = ze.getName();
String newName = getUnicodeStringIfOriginalMatches(name, nc.name);
if (newName != null && !originalName.equals(newName)) {
ze.setName(newName);
nameMap.remove(originalName);
nameMap.put(newName, ze);
}
if (nc.comment != null && nc.comment.length > 0) {
UnicodeCommentExtraField cmt = (UnicodeCommentExtraField)
ze.getExtraField(UnicodeCommentExtraField.UCOM_ID);
String newComment =
getUnicodeStringIfOriginalMatches(cmt, nc.comment);
if (newComment != null) {
ze.setComment(newComment);
}
}
}
/**
* If the stored CRC matches the one of the given name, return the
* Unicode name of the given field.
*
* If the field is null or the CRCs don't match, return null
* instead.
*/
private String getUnicodeStringIfOriginalMatches(AbstractUnicodeExtraField f,
byte[] orig) {
if (f != null) {
CRC32 crc32 = new CRC32();
crc32.update(orig);
long origCRC32 = crc32.getValue();
if (origCRC32 == f.getNameCRC32()) {
try {
return ZipEncodingHelper
.UTF8_ZIP_ENCODING.decode(f.getUnicodeName());
} catch (IOException ex) {
// UTF-8 unsupported? should be impossible the
// Unicode*ExtraField must contain some bad bytes
// TODO log this anywhere?
return null;
}
}
}
return null;
}
/**
* 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;
}
public int read() throws IOException {
if (remaining-- <= 0) {
if (addDummyByte) {
addDummyByte = false;
return 0;
}
return -1;
}
synchronized (archive) {
archive.seek(loc++);
return archive.read();
}
}
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;
}
}
}