/**
* 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.googlecode.d2j.util.zip;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
import java.util.zip.ZipException;
/**
* This is code is get from Android 4.4.2 intent to read as more zip as possible
*
* Ignore GPBF_ENCRYPTED_FLAG
*
* Allow duplicate ZipEntry
*
* Allow Nul byte in ZipEntry name
*
*/
public class ZipFile implements AutoCloseable, ZipConstants {
/**
* General Purpose Bit Flags, Bit 0. If set, indicates that the file is encrypted.
*/
static final int GPBF_ENCRYPTED_FLAG = 1 << 0;
/**
* General Purpose Bit Flags, Bit 3. If this bit is set, the fields crc-32, compressed size and uncompressed size
* are set to zero in the local header. The correct values are put in the data descriptor immediately following the
* compressed data. (Note: PKZIP version 2.04g for DOS only recognizes this bit for method 8 compression, newer
* versions of PKZIP recognize this bit for any compression method.)
*/
static final int GPBF_DATA_DESCRIPTOR_FLAG = 1 << 3;
/**
* General Purpose Bit Flags, Bit 11. Language encoding flag (EFS). If this bit is set, the filename and comment
* fields for this file must be encoded using UTF-8.
*/
static final int GPBF_UTF8_FLAG = 1 << 11;
/**
* Supported General Purpose Bit Flags Mask. Bit mask of bits not supported. Note: The only bit that we will enforce
* at this time is the encrypted bit. Although other bits are not supported, we must not enforce them as this could
* break some legitimate use cases (See http://b/8617715).
*/
static final int GPBF_UNSUPPORTED_MASK = GPBF_ENCRYPTED_FLAG;
private List<ZipEntry> entries;
private String comment;
final ByteBuffer raf;
public ZipFile(ByteBuffer in) throws IOException {
raf = in.asReadOnlyBuffer().order(ByteOrder.LITTLE_ENDIAN);
readCentralDir();
}
public ZipFile(byte[] data) throws IOException {
this(ByteBuffer.wrap(data));
}
public List<? extends ZipEntry> entries() {
return entries;
}
/**
* Returns this file's comment, or null if it doesn't have one. See {@link java.util.zip.ZipOutputStream#setComment}
* .
*
* @throws IllegalStateException
* if this zip file has been closed.
* @since 1.7
*/
public String getComment() {
return comment;
}
public ZipEntry findFirstEntry(String entryName) {
if (entryName == null) {
throw new NullPointerException("entryName == null");
}
ZipEntry ze = findFirstEntry0(entryName);
if (ze == null) {
ze = findFirstEntry0(entryName + "/");
}
return ze;
}
private ZipEntry findFirstEntry0(String entryName) {
for (ZipEntry e : entries) {
if (e.getName().equals(entryName)) {
return e;
}
}
return null;
}
/**
* Returns an input stream on the data of the specified {@code android.ZipEntry}.
*
* @param entry
* the android.ZipEntry.
* @return an input stream of the data contained in the {@code android.ZipEntry}.
* @throws java.io.IOException
* if an {@code IOException} occurs.
* @throws IllegalStateException
* if this zip file has been closed.
*/
public InputStream getInputStream(ZipEntry entry) throws IOException {
// We don't know the entry data's start position. All we have is the
// position of the entry's local header.
// http://www.pkware.com/documents/casestudies/APPNOTE.TXT
final ByteBuffer is = (ByteBuffer) raf.duplicate().order(ByteOrder.LITTLE_ENDIAN)
.position((int) entry.localHeaderRelOffset);
skip(is, 6); // skip check localMagic
// final int localMagic = is.getInt();
// if (localMagic != LOCSIG) {
// throwZipException("Local File Header", localMagic);
// }
// skip(is, 2);
// At position 6 we find the General Purpose Bit Flag.
int gpbf = is.getShort() & 0xffff;
// Offset 26 has the file name length, and offset 28 has the extra field length.
// These lengths can differ from the ones in the central header.
skip(is, 18);
int fileNameLength = is.getShort() & 0xffff;
int extraFieldLength = is.getShort() & 0xffff;
// Skip the variable-size file name and extra field data.
skip(is, fileNameLength + extraFieldLength);
if (entry.compressionMethod == ZipEntry.STORED) {
final ByteBuffer buf = (ByteBuffer) is.slice().order(ByteOrder.LITTLE_ENDIAN).limit((int) entry.size);
return new ByteBufferBackedInputStream(buf);
} else {
final ByteBuffer buf = (ByteBuffer) is.slice().order(ByteOrder.LITTLE_ENDIAN)
.limit((int) entry.compressedSize);
int bufSize = Math.max(1024, (int) Math.min(entry.getSize(), 65535L));
return new ZipInflaterInputStream(new ByteBufferBackedInputStream(buf), new Inflater(true), bufSize, entry);
}
}
static void skip(ByteBuffer is, int i) {
is.position(is.position() + i);
}
/**
* Returns the number of {@code ZipEntries} in this {@code android.ZipFile}.
*
* @return the number of entries in this file.
* @throws IllegalStateException
* if this zip file has been closed.
*/
public int size() {
return entries.size();
}
/**
* Find the central directory and read the contents.
*
* <p>
* The central directory can be followed by a variable-length comment field, so we have to scan through it
* backwards. The comment is at most 64K, plus we have 18 bytes for the end-of-central-dir stuff itself, plus
* apparently sometimes people throw random junk on the end just for the fun of it.
*
* <p>
* This is all a little wobbly. If the wrong value ends up in the EOCD area, we're hosed. This appears to be the way
* that everybody handles it though, so we're in good company if this fails.
*/
private void readCentralDir() throws IOException {
ByteBuffer raf = this.raf;
// Scan back, looking for the End Of Central Directory field. If the zip file doesn't
// have an overall comment (unrelated to any per-entry comments), we'll hit the EOCD
// on the first try.
// No need to synchronize raf here -- we only do this when we first open the zip file.
long scanOffset = raf.limit() - ENDHDR;
if (scanOffset < 0) {
throw new ZipException("File too short to be a zip file: " + raf.limit());
}
// not check Magic
// raf.position(0);
// final int headerMagic = raf.getInt();
// if (headerMagic != LOCSIG) {
// throw new ZipException("Not a zip archive");
// }
long stopOffset = scanOffset - 65536;
if (stopOffset < 0) {
stopOffset = 0;
}
while (true) {
raf.position((int) scanOffset);
if (raf.getInt() == ENDSIG) {
break;
}
scanOffset--;
if (scanOffset < stopOffset) {
throw new ZipException("End Of Central Directory signature not found");
}
}
// Read the End Of Central Directory. ENDHDR includes the signature bytes,
// which we've already read.
// Pull out the information we need.
int diskNumber = raf.getShort() & 0xffff;
int diskWithCentralDir = raf.getShort() & 0xffff;
int numEntries = raf.getShort() & 0xffff;
int totalNumEntries = raf.getShort() & 0xffff;
skip(raf, 4); // Ignore centralDirSize.
long centralDirOffset = ((long) raf.getInt()) & 0xffffffffL;
int commentLength = raf.getShort() & 0xffff;
if (numEntries != totalNumEntries || diskNumber != 0 || diskWithCentralDir != 0) {
throw new ZipException("Spanned archives not supported");
}
boolean skipCommentsAndExtra = true;
if (commentLength > 0) {
if (skipCommentsAndExtra) {
skip(raf, commentLength);
} else {
byte[] commentBytes = new byte[commentLength];
raf.get(commentBytes);
comment = new String(commentBytes, 0, commentBytes.length, StandardCharsets.UTF_8);
}
}
// Seek to the first CDE and read all entries.
// We have to do this now (from the constructor) rather than lazily because the
// public API doesn't allow us to throw IOException except from the constructor
// or from getInputStream.
ByteBuffer buf = (ByteBuffer) raf.duplicate().order(ByteOrder.LITTLE_ENDIAN).position((int) centralDirOffset);
entries = new ArrayList<>(numEntries);
for (int i = 0; i < numEntries; ++i) {
ZipEntry newEntry = new ZipEntry(buf, skipCommentsAndExtra);
if (newEntry.localHeaderRelOffset >= centralDirOffset) {
// Ignore the entry
// throw new ZipException("Local file header offset is after central directory");
} else {
entries.add(newEntry);
}
}
}
static void throwZipException(String msg, int magic) throws ZipException {
final String hexString = String.format("0x%08x", magic);
throw new ZipException(msg + " signature not found; was " + hexString);
}
@Override
public void close() throws IOException {
}
static class ZipInflaterInputStream extends InflaterInputStream {
private final ZipEntry entry;
private long bytesRead = 0;
public ZipInflaterInputStream(InputStream is, Inflater inf, int bsize, ZipEntry entry) {
super(is, inf, bsize);
this.entry = entry;
}
@Override
public int read(byte[] buffer, int byteOffset, int byteCount) throws IOException {
final int i;
try {
i = super.read(buffer, byteOffset, byteCount);
} catch (IOException e) {
throw new IOException("Error reading data for " + entry.getName() + " near offset " + bytesRead, e);
}
if (i == -1) {
if (entry.size != bytesRead) {
throw new IOException("Size mismatch on inflated file: " + bytesRead + " vs " + entry.size);
}
} else {
bytesRead += i;
}
return i;
}
@Override
public int available() throws IOException {
return super.available() == 0 ? 0 : (int) (entry.getSize() - bytesRead);
}
}
private static class ByteBufferBackedInputStream extends InputStream {
private final ByteBuffer buf;
public ByteBufferBackedInputStream(ByteBuffer buf) {
this.buf = buf;
}
@Override
public int read() throws IOException {
if (!buf.hasRemaining()) {
return -1;
}
return buf.get() & 0xFF;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (!buf.hasRemaining()) {
return -1;
}
len = Math.min(len, buf.remaining());
buf.get(b, off, len);
return len;
}
}
}