/*
* 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.tools.zip;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.util.Calendar;
import java.util.Date;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
import java.util.zip.ZipException;
/**
* Replacement for <code>java.util.ZipFile</code>.
*
* <p>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.tools.zip.ZipEntry</code> instead of
* <code>java.util.zip.ZipEntry</code>.</p>
*
* <p>It doesn't extend <code>java.util.zip.ZipFile</code> as it would
* have to reimplement all methods anyway. Like
* <code>java.util.ZipFile</code>, it uses RandomAccessFile under the
* covers and supports compressed and uncompressed entries.</p>
*
* <p>The method signatures mimic the ones of
* <code>java.util.zip.ZipFile</code>, with a couple of exceptions:
*
* <ul>
* <li>There is no getName method.</li>
* <li>entries has been renamed to getEntries.</li>
* <li>getEntries and getEntry return
* <code>org.apache.tools.zip.ZipEntry</code> instances.</li>
* <li>close is allowed to throw IOException.</li>
* </ul>
*
*/
public class ZipFile {
/**
* Maps ZipEntrys to Longs, recording the offsets of the local
* file headers.
*/
private Hashtable entries = new Hashtable(509);
/**
* Maps String to ZipEntrys, name -> actual entry.
*/
private Hashtable nameMap = new Hashtable(509);
private static final class OffsetEntry {
private long headerOffset = -1;
private long dataOffset = -1;
}
/**
* The encoding to use for filenames and the file comment.
*
* <p>For a list of possible values see <a
* href="http://java.sun.com/j2se/1.5.0/docs/guide/intl/encoding.doc.html">http://java.sun.com/j2se/1.5.0/docs/guide/intl/encoding.doc.html</a>.
* Defaults to the platform's default character encoding.</p>
*/
private String encoding = null;
/**
* The actual data source.
*/
private RandomAccessFile archive;
/**
* 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.
*
* @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);
}
/**
* 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
*
* @throws IOException if an error occurs while reading the file.
*/
public ZipFile(File f, String encoding) throws IOException {
this.encoding = encoding;
archive = new RandomAccessFile(f, "r");
try {
populateFromCentralDirectory();
resolveLocalFileHeaderData();
} catch (IOException e) {
try {
archive.close();
} catch (IOException e2) {
// swallow, throw the original exception instead
}
throw e;
}
}
/**
* 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 entries.keys();
}
/**
* Returns a named entry - or <code>null</code> if no entry by
* that name exists.
* @param name name of the entry.
* @return the ZipEntry corresponding to the given name - or
* <code>null</code> 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();
return new InflaterInputStream(bis, new Inflater(true));
default:
throw new ZipException("Found unsupported compression method "
+ ze.getMethod());
}
}
private static final int CFH_LEN =
/* version made by */ 2
/* version needed to extract */ + 2
/* general purpose bit flag */ + 2
/* compression method */ + 2
/* last mod file time */ + 2
/* last mod file date */ + 2
/* crc-32 */ + 4
/* compressed size */ + 4
/* uncompressed size */ + 4
/* filename length */ + 2
/* extra field length */ + 2
/* file comment length */ + 2
/* disk number start */ + 2
/* internal file attributes */ + 2
/* external file attributes */ + 4
/* relative offset of local header */ + 4;
/**
* Reads the central directory of the given archive and populates
* the internal tables with ZipEntry instances.
*
* <p>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.</p>
*/
private void populateFromCentralDirectory()
throws IOException {
positionAtCentralDirectory();
byte[] cfh = new byte[CFH_LEN];
byte[] signatureBytes = new byte[4];
archive.readFully(signatureBytes);
long sig = ZipLong.getValue(signatureBytes);
final long cfhSig = ZipLong.getValue(ZipOutputStream.CFH_SIG);
while (sig == cfhSig) {
archive.readFully(cfh);
int off = 0;
ZipEntry ze = new ZipEntry();
int versionMadeBy = ZipShort.getValue(cfh, off);
off += 2;
ze.setPlatform((versionMadeBy >> 8) & 0x0F);
off += 4; // skip version info and general purpose byte
ze.setMethod(ZipShort.getValue(cfh, off));
off += 2;
// 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 += 4;
ze.setCrc(ZipLong.getValue(cfh, off));
off += 4;
ze.setCompressedSize(ZipLong.getValue(cfh, off));
off += 4;
ze.setSize(ZipLong.getValue(cfh, off));
off += 4;
int fileNameLen = ZipShort.getValue(cfh, off);
off += 2;
int extraLen = ZipShort.getValue(cfh, off);
off += 2;
int commentLen = ZipShort.getValue(cfh, off);
off += 2;
off += 2; // disk number
ze.setInternalAttributes(ZipShort.getValue(cfh, off));
off += 2;
ze.setExternalAttributes(ZipLong.getValue(cfh, off));
off += 4;
byte[] fileName = new byte[fileNameLen];
archive.readFully(fileName);
ze.setName(getString(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);
archive.skipBytes(extraLen);
byte[] comment = new byte[commentLen];
archive.readFully(comment);
ze.setComment(getString(comment));
archive.readFully(signatureBytes);
sig = ZipLong.getValue(signatureBytes);
}
}
private static final int MIN_EOCD_SIZE =
/* end of central dir signature */ 4
/* number of this disk */ + 2
/* number of the disk with the */
/* start of the central directory */ + 2
/* total number of entries in */
/* the central dir on this disk */ + 2
/* total number of entries in */
/* the central dir */ + 2
/* size of the central directory */ + 4
/* offset of start of central */
/* directory with respect to */
/* the starting disk number */ + 4
/* zipfile comment length */ + 2;
private static final int CFD_LOCATOR_OFFSET =
/* end of central dir signature */ 4
/* number of this disk */ + 2
/* number of the disk with the */
/* start of the central directory */ + 2
/* total number of entries in */
/* the central dir on this disk */ + 2
/* total number of entries in */
/* the central dir */ + 2
/* size of the central directory */ + 4;
/**
* 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;
if (off >= 0) {
archive.seek(off);
byte[] sig = ZipOutputStream.EOCD_SIG;
int curr = archive.read();
while (curr != -1) {
if (curr == sig[0]) {
curr = archive.read();
if (curr == sig[1]) {
curr = archive.read();
if (curr == sig[2]) {
curr = archive.read();
if (curr == sig[3]) {
found = true;
break;
}
}
}
}
archive.seek(--off);
curr = archive.read();
}
}
if (!found) {
throw new ZipException("archive is not a ZIP archive");
}
archive.seek(off + CFD_LOCATOR_OFFSET);
byte[] cfdOffset = new byte[4];
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 */ 4
/* version needed to extract */ + 2
/* general purpose bit flag */ + 2
/* compression method */ + 2
/* last mod file time */ + 2
/* last mod file date */ + 2
/* crc-32 */ + 4
/* compressed size */ + 4
/* uncompressed size */ + 4;
/**
* Walks through all recorded entries and adds the data available
* from the local file header.
*
* <p>Also records the offsets for the data to read from the
* entries.</p>
*/
private void resolveLocalFileHeaderData()
throws IOException {
Enumeration e = getEntries();
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[2];
archive.readFully(b);
int fileNameLen = ZipShort.getValue(b);
archive.readFully(b);
int extraFieldLen = ZipShort.getValue(b);
archive.skipBytes(fileNameLen);
byte[] localExtraData = new byte[extraFieldLen];
archive.readFully(localExtraData);
ze.setExtra(localExtraData);
/*dataOffsets.put(ze,
new Long(offset + LFH_OFFSET_FOR_FILENAME_LENGTH
+ 2 + 2 + fileNameLen + extraFieldLen));
*/
offsetEntry.dataOffset = offset + LFH_OFFSET_FOR_FILENAME_LENGTH
+ 2 + 2 + fileNameLen + extraFieldLen;
}
}
/**
* 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();
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);
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 {
if (encoding == null) {
return new String(bytes);
} else {
try {
return new String(bytes, encoding);
} catch (UnsupportedEncodingException uee) {
throw new ZipException(uee.getMessage());
}
}
}
/**
* 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;
}
}
}
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