/*
* JEF - Copyright 2009-2010 Jiyi (mr.jiyi@gmail.com)
*
* Licensed 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 jef.tools.zip;
/*
* @(#)ZipInputStream.java 1.44 07/06/15
*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.util.zip.CRC32;
import java.util.zip.Inflater;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import jef.common.log.LogUtil;
/**
* This class implements an input stream filter for reading files in the ZIP
* file format. Includes support for both compressed and uncompressed entries.
*
* @author David Connelly
* @version 1.44, 06/15/07
*/
public class ZipInputStream extends InflaterInputStream implements ZipConstants {
private ZipEntry entry;
private int flag;
private CRC32 crc = new CRC32();
private long remaining;
private byte[] tmpbuf = new byte[512];
private static final int STORED = ZipEntry.STORED;
private static final int DEFLATED = ZipEntry.DEFLATED;
private boolean closed = false;
// this flag is set to true after EOF has reached for
// one entry
private boolean entryEOF = false;
/**
* Check to make sure that this stream has not been closed
*/
private void ensureOpen() throws IOException {
if (closed) {
throw new IOException("Stream closed");
}
}
/**
* Creates a new ZIP input stream.
*
* @param in
* the actual input stream
*/
public ZipInputStream(InputStream in) {
this(in,null);
}
public ZipInputStream(InputStream in,String encoding) {
super(new PushbackInputStream(in, 512), new Inflater(true), 512);
usesDefaultInflater = true;
this.encoding=encoding;
if (in == null) {
throw new NullPointerException("in is null");
}
}
/**
* Reads the next ZIP file entry and positions the stream at the beginning
* of the entry data.
*
* @return the next ZIP file entry, or null if there are no more entries
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public ZipEntry getNextEntry() throws IOException {
ensureOpen();
if (entry != null) {
closeEntry();
}
crc.reset();
inf.reset();
if ((entry = readLOC()) == null) {
return null;
}
if (entry.getMethod() == STORED) {
remaining = entry.getSize();
}
entryEOF = false;
return entry;
}
/**
* Closes the current ZIP entry and positions the stream for reading the
* next entry.
*
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public void closeEntry() throws IOException {
ensureOpen();
while (read(tmpbuf, 0, tmpbuf.length) != -1)
;
entryEOF = true;
}
/**
* Returns 0 after EOF has reached for the current entry data, otherwise
* always return 1.
* <p>
* Programs should not count on this method to return the actual number of
* bytes that could be read without blocking.
*
* @return 1 before EOF and 0 after EOF has reached for current entry.
* @exception IOException
* if an I/O error occurs.
*
*/
public int available() throws IOException {
ensureOpen();
if (entryEOF) {
return 0;
} else {
return 1;
}
}
/**
* Reads from the current ZIP entry into an array of bytes. If
* <code>len</code> is not zero, the method blocks until some input is
* available; otherwise, no bytes are read and <code>0</code> is returned.
*
* @param b
* the buffer into which the data is read
* @param off
* the start offset in the destination array <code>b</code>
* @param len
* the maximum number of bytes read
* @return the actual number of bytes read, or -1 if the end of the entry is
* reached
* @exception NullPointerException
* If <code>b</code> is <code>null</code>.
* @exception IndexOutOfBoundsException
* If <code>off</code> is negative, <code>len</code> is
* negative, or <code>len</code> is greater than
* <code>b.length - off</code>
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public int read(byte[] b, int off, int len) throws IOException {
ensureOpen();
if (off < 0 || len < 0 || off > b.length - len) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return 0;
}
if (entry == null) {
return -1;
}
switch (entry.getMethod()) {
case DEFLATED:
len = super.read(b, off, len);
if (len == -1) {
readEnd(entry);
entryEOF = true;
entry = null;
} else {
crc.update(b, off, len);
}
return len;
case STORED:
if (remaining <= 0) {
entryEOF = true;
entry = null;
return -1;
}
if (len > remaining) {
len = (int) remaining;
}
len = in.read(b, off, len);
if (len == -1) {
throw new ZipException("unexpected EOF");
}
crc.update(b, off, len);
remaining -= len;
if (remaining == 0 && entry.getCrc() != crc.getValue()) {
throw new ZipException("invalid entry CRC (expected 0x" + Long.toHexString(entry.getCrc()) + " but got 0x" + Long.toHexString(crc.getValue()) + ")");
}
return len;
default:
throw new ZipException("invalid compression method");
}
}
/**
* Skips specified number of bytes in the current ZIP entry.
*
* @param n
* the number of bytes to skip
* @return the actual number of bytes skipped
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O error has occurred
* @exception IllegalArgumentException
* if n < 0
*/
public long skip(long n) throws IOException {
if (n < 0) {
throw new IllegalArgumentException("negative skip length");
}
ensureOpen();
int max = (int) Math.min(n, Integer.MAX_VALUE);
int total = 0;
while (total < max) {
int len = max - total;
if (len > tmpbuf.length) {
len = tmpbuf.length;
}
len = read(tmpbuf, 0, len);
if (len == -1) {
entryEOF = true;
break;
}
total += len;
}
return total;
}
/**
* Closes this input stream and releases any system resources associated
* with the stream.
*
* @exception IOException
* if an I/O error has occurred
*/
public void close() throws IOException {
if (!closed) {
super.close();
closed = true;
}
}
private byte[] b = new byte[256];
private String encoding;
/*
* Reads local file (LOC) header for next entry.
*/
private ZipEntry readLOC() throws IOException {
try {
readFully(tmpbuf, 0, LOCHDR);
} catch (EOFException e) {
return null;
}
if (get32(tmpbuf, 0) != LOCSIG) {
return null;
}
// get the entry name and create the ZipEntry first
int len = get16(tmpbuf, LOCNAM);
int blen = b.length;
if (len > blen) {
do
blen = blen * 2;
while (len > blen);
b = new byte[blen];
}
readFully(b, 0, len);
// ZipEntry e = createZipEntry(getUTF8String(b, 0, len));
ZipEntry e = null;
try {
if (this.encoding == null)
e = createZipEntry(new String(b, 0, len));
else
e = createZipEntry(new String(b, 0, len, this.encoding));
;
} catch (Exception byteE) {
LogUtil.exception(byteE);
e = createZipEntry(getUTF8String(b, 0, len));
}
// now get the remaining fields for the entry
flag = get16(tmpbuf, LOCFLG);
if ((flag & 1) == 1) {
throw new ZipException("encrypted ZIP entry not supported");
}
e.setMethod(get16(tmpbuf, LOCHOW));
e.setTime(get32(tmpbuf, LOCTIM));
if ((flag & 8) == 8) {
/* "Data Descriptor" present */
if (e.getMethod() != DEFLATED) {
throw new ZipException("only DEFLATED entries can have EXT descriptor");
}
} else {
e.setCrc(get32(tmpbuf, LOCCRC));
e.setCompressedSize(get32(tmpbuf, LOCSIZ));
e.setSize(get32(tmpbuf, LOCLEN));
}
len = get16(tmpbuf, LOCEXT);
if (len > 0) {
byte[] bb = new byte[len];
readFully(bb, 0, len);
e.setExtra(bb);
}
return e;
}
/*
* Fetches a UTF8-encoded String from the specified byte array.
*/
private static String getUTF8String(byte[] b, int off, int len) {
// First, count the number of characters in the sequence
int count = 0;
int max = off + len;
int i = off;
while (i < max) {
int c = b[i++] & 0xff;
switch (c >> 4) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
// 0xxxxxxx
count++;
break;
case 12:
case 13:
// 110xxxxx 10xxxxxx
if ((int) (b[i++] & 0xc0) != 0x80) {
throw new IllegalArgumentException();
}
count++;
break;
case 14:
// 1110xxxx 10xxxxxx 10xxxxxx
if (((int) (b[i++] & 0xc0) != 0x80) || ((int) (b[i++] & 0xc0) != 0x80)) {
throw new IllegalArgumentException();
}
count++;
break;
default:
// 10xxxxxx, 1111xxxx
throw new IllegalArgumentException();
}
}
if (i != max) {
throw new IllegalArgumentException();
}
// Now decode the characters...
char[] cs = new char[count];
i = 0;
while (off < max) {
int c = b[off++] & 0xff;
switch (c >> 4) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
// 0xxxxxxx
cs[i++] = (char) c;
break;
case 12:
case 13:
// 110xxxxx 10xxxxxx
cs[i++] = (char) (((c & 0x1f) << 6) | (b[off++] & 0x3f));
break;
case 14:
// 1110xxxx 10xxxxxx 10xxxxxx
int t = (b[off++] & 0x3f) << 6;
cs[i++] = (char) (((c & 0x0f) << 12) | t | (b[off++] & 0x3f));
break;
default:
// 10xxxxxx, 1111xxxx
throw new IllegalArgumentException();
}
}
return new String(cs, 0, count);
}
/**
* Creates a new <code>ZipEntry</code> object for the specified entry name.
*
* @param name
* the ZIP file entry name
* @return the ZipEntry just created
*/
protected ZipEntry createZipEntry(String name) {
return new ZipEntry(name);
}
/*
* Reads end of deflated entry as well as EXT descriptor if present.
*/
private void readEnd(ZipEntry e) throws IOException {
int n = inf.getRemaining();
if (n > 0) {
((PushbackInputStream) in).unread(buf, len - n, n);
}
if ((flag & 8) == 8) {
/* "Data Descriptor" present */
readFully(tmpbuf, 0, EXTHDR);
long sig = get32(tmpbuf, 0);
if (sig != EXTSIG) { // no EXTSIG present
e.setCrc(sig);
e.setCompressedSize(get32(tmpbuf, EXTSIZ - EXTCRC));
e.setSize(get32(tmpbuf, EXTLEN - EXTCRC));
((PushbackInputStream) in).unread(tmpbuf, EXTHDR - EXTCRC - 1, EXTCRC);
} else {
e.setCrc(get32(tmpbuf, EXTCRC));
e.setCompressedSize(get32(tmpbuf, EXTSIZ));
e.setSize(get32(tmpbuf, EXTLEN));
}
}
if (e.getSize() != inf.getBytesWritten()) {
throw new ZipException("invalid entry size (expected " + e.getSize() + " but got " + inf.getBytesWritten() + " bytes)");
}
if (e.getCompressedSize() != inf.getBytesRead()) {
throw new ZipException("invalid entry compressed size (expected " + e.getCompressedSize() + " but got " + inf.getBytesRead() + " bytes)");
}
if (e.getCrc() != crc.getValue()) {
throw new ZipException("invalid entry CRC (expected 0x" + Long.toHexString(e.getCrc()) + " but got 0x" + Long.toHexString(crc.getValue()) + ")");
}
}
/*
* Reads bytes, blocking until all bytes are read.
*/
private void readFully(byte[] b, int off, int len) throws IOException {
while (len > 0) {
int n = in.read(b, off, len);
if (n == -1) {
throw new EOFException();
}
off += n;
len -= n;
}
}
/*
* Fetches unsigned 16-bit value from byte array at specified offset. The
* bytes are assumed to be in Intel (little-endian) byte order.
*/
private static final int get16(byte b[], int off) {
return (b[off] & 0xff) | ((b[off + 1] & 0xff) << 8);
}
/*
* Fetches unsigned 32-bit value from byte array at specified offset. The
* bytes are assumed to be in Intel (little-endian) byte order.
*/
private static final long get32(byte b[], int off) {
return get16(b, off) | ((long) get16(b, off + 2) << 16);
}
}