/*
* 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;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.HashSet;
import java.util.Vector;
import java.util.zip.CRC32;
import java.util.zip.Deflater;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
/**
* This class implements an output stream filter for writing files in the ZIP
* file format. Includes support for both compressed and uncompressed entries.
*
* @author Jiyi
* @version 1.35, 07/31/06
*/
public class ZipOutputStream extends DeflaterOutputStream implements ZipConstants {
public static String DEFAULT_NAME_ENCODING=Charset.defaultCharset().name();
private static class XEntry {
public final ZipEntry entry;
public final long offset;
public final int flag;
public XEntry(ZipEntry entry, long offset) {
this.entry = entry;
this.offset = offset;
// store size, compressed size, and crc-32 in data descriptor
// immediately following the compressed entry data
// store size, compressed size, and crc-32 in LOC header
this.flag = (entry.getMethod() == DEFLATED && (entry.getSize() == -1 || entry.getCompressedSize() == -1 || entry.getCrc() == -1))? 8: 0;
}
}
private String encoding;
private XEntry current;
private Vector<XEntry> xentries = new Vector<XEntry>();
private HashSet<String> names = new HashSet<String>();
private CRC32 crc = new CRC32();
private long written = 0;
private long locoff = 0;
private byte[] comment;
private int method = DEFLATED;
private boolean finished;
private boolean closed = false;
public String getEncoding() {
return encoding;
}
private byte[] encoding(String str) {
if (encoding == null) {
return str.getBytes();
} else {
try {
return str.getBytes(encoding);
} catch (UnsupportedEncodingException e) {
throw new IllegalArgumentException(e);
}
}
}
private static int version(ZipEntry e) throws ZipException {
switch (e.getMethod()) {
case DEFLATED:
return 20;
case STORED:
return 10;
default:
throw new ZipException("unsupported compression method");
}
}
/**
* Checks to make sure that this stream has not been closed.
*/
private void ensureOpen() throws IOException {
if (closed) {
throw new IOException("Stream closed");
}
}
/**
* Compression method for uncompressed (STORED) entries.
*/
public static final int STORED = ZipEntry.STORED;
/**
* Compression method for compressed (DEFLATED) entries.
*/
public static final int DEFLATED = ZipEntry.DEFLATED;
/**
* Creates a new ZIP output stream.
*
* @param out
* the actual output stream
*/
public ZipOutputStream(OutputStream out) {
this(out, DEFAULT_NAME_ENCODING);
}
public ZipOutputStream(OutputStream out, String encoding) {
super(out, new Deflater(Deflater.DEFAULT_COMPRESSION, true));
usesDefaultDeflater = true;
this.encoding=encoding;
}
/**
* Sets the ZIP file comment.
*
* @param comment
* the comment string
* @exception IllegalArgumentException
* if the length of the specified ZIP file comment is greater
* than 0xFFFF bytes
*/
public void setComment(String comment) {
byte[] tmp = this.encoding(comment);
if (comment != null && comment.length() > 0xffff / 3 && tmp.length > 0xffff) {
throw new IllegalArgumentException("ZIP file comment too long.");
}
}
/**
* Sets the default compression method for subsequent entries. This default
* will be used whenever the compression method is not specified for an
* individual ZIP file entry, and is initially set to DEFLATED.
*
* @param method
* the default compression method
* @exception IllegalArgumentException
* if the specified compression method is invalid
*/
public void setMethod(int method) {
if (method != DEFLATED && method != STORED) {
throw new IllegalArgumentException("invalid compression method");
}
this.method = method;
}
/**
* Sets the compression level for subsequent entries which are DEFLATED. The
* default setting is DEFAULT_COMPRESSION.
*
* @param level
* the compression level (0-9)
* @exception IllegalArgumentException
* if the compression level is invalid
*/
public void setLevel(int level) {
def.setLevel(level);
}
/**
* Begins writing a new ZIP file entry and positions the stream to the start
* of the entry data. Closes the current entry if still active. The default
* compression method will be used if no compression method was specified
* for the entry, and the current time will be used if the entry has no set
* modification time.
*
* @param e
* the ZIP entry to be written
* @exception ZipException
* if a ZIP format error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public void putNextEntry(ZipEntry e) throws IOException {
ensureOpen();
if (current != null) {
closeEntry(); // close previous entry
}
if (e.getTime() == -1) {
e.setTime(System.currentTimeMillis());
}
if (e.getMethod() == -1) {
e.setMethod(method); // use default method
}
switch (e.getMethod()) {
case DEFLATED:
break;
case STORED:
// compressed size, uncompressed size, and crc-32 must all be
// set for entries using STORED compression method
if (e.getSize() == -1) {
e.setSize(e.getCompressedSize());
} else if (e.getCompressedSize() == -1) {
e.setCompressedSize(e.getSize());
} else if (e.getSize() != e.getCompressedSize()) {
throw new ZipException("STORED entry where compressed != uncompressed size");
}
if (e.getSize() == -1 || e.getCrc() == -1) {
throw new ZipException("STORED entry missing size, compressed size, or crc-32");
}
break;
default:
throw new ZipException("unsupported compression method");
}
if (!names.add(e.getName())) {
throw new ZipException("duplicate entry: " + e.getName());
}
current = new XEntry(e, written);
xentries.add(current);
writeLOC(current);
}
/**
* Closes the current ZIP entry and positions the stream for writing the
* next entry.
*
* @exception ZipException
* if a ZIP format error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public void closeEntry() throws IOException {
ensureOpen();
if (current != null) {
ZipEntry e = current.entry;
switch (e.getMethod()) {
case DEFLATED:
def.finish();
while (!def.finished()) {
deflate();
}
if ((current.flag & 8) == 0) {
// verify size, compressed size, and crc-32 settings
if (e.getSize() != def.getBytesRead()) {
throw new ZipException("invalid entry size (expected " + e.getSize() + " but got " + def.getBytesRead() + " bytes)");
}
if (e.getCompressedSize() != def.getBytesWritten()) {
throw new ZipException("invalid entry compressed size (expected " + e.getCompressedSize() + " but got " + def.getBytesWritten() + " bytes)");
}
if (e.getCrc() != crc.getValue()) {
throw new ZipException("invalid entry CRC-32 (expected 0x" + Long.toHexString(e.getCrc()) + " but got 0x" + Long.toHexString(crc.getValue()) + ")");
}
} else {
e.setSize(def.getBytesRead());
e.setCompressedSize(def.getBytesWritten());
e.setCrc(crc.getValue());
writeEXT(e);
}
def.reset();
written += e.getCompressedSize();
break;
case STORED:
// we already know that both e.size and e.csize are the same
if (e.getSize() != written - locoff) {
throw new ZipException("invalid entry size (expected " + e.getSize() + " but got " + (written - locoff) + " bytes)");
}
if (e.getCrc() != crc.getValue()) {
throw new ZipException("invalid entry crc-32 (expected 0x" + Long.toHexString(e.getCrc()) + " but got 0x" + Long.toHexString(crc.getValue()) + ")");
}
break;
default:
throw new ZipException("invalid compression method");
}
crc.reset();
current = null;
}
}
/**
* Writes an array of bytes to the current ZIP entry data. This method will
* block until all the bytes are written.
*
* @param b
* the data to be written
* @param off
* the start offset in the data
* @param len
* the number of bytes that are written
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public synchronized void write(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;
}
if (current == null) {
throw new ZipException("no current ZIP entry");
}
ZipEntry entry = current.entry;
switch (entry.getMethod()) {
case DEFLATED:
super.write(b, off, len);
break;
case STORED:
written += len;
if (written - locoff > entry.getSize()) {
throw new ZipException("attempt to write past end of STORED entry");
}
out.write(b, off, len);
break;
default:
throw new ZipException("invalid compression method");
}
crc.update(b, off, len);
}
/**
* Finishes writing the contents of the ZIP output stream without closing
* the underlying stream. Use this method when applying multiple filters in
* succession to the same output stream.
*
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O exception has occurred
*/
public void finish() throws IOException {
ensureOpen();
if (finished) {
return;
}
if (current != null) {
closeEntry();
}
if (xentries.size() < 1) {
throw new ZipException("ZIP file must have at least one entry");
}
// write central directory
long off = written;
for (XEntry xentry : xentries)
writeCEN(xentry);
writeEND(off, written - off);
finished = true;
}
/**
* Closes the ZIP output stream as well as the stream being filtered.
*
* @exception ZipException
* if a ZIP file error has occurred
* @exception IOException
* if an I/O error has occurred
*/
public void close() throws IOException {
if (!closed) {
super.close();
closed = true;
}
}
/*
* Writes local file (LOC) header for specified entry.
*/
private void writeLOC(XEntry xentry) throws IOException {
ZipEntry e = xentry.entry;
int flag = xentry.flag;
writeInt(LOCSIG); // LOC header signature
writeShort(version(e)); // version needed to extract
writeShort(flag); // general purpose bit flag
writeShort(e.getMethod()); // compression method
writeInt(e.getTime()); // last modification time
if ((flag & 8) == 8) {
// store size, uncompressed size, and crc-32 in data descriptor
// immediately following compressed entry data
writeInt(0);
writeInt(0);
writeInt(0);
} else {
writeInt(e.getCrc()); // crc-32
writeInt(e.getCompressedSize()); // compressed size
writeInt(e.getSize()); // uncompressed size
}
byte[] nameBytes = encoding(e.getName());
writeShort(nameBytes.length);
writeShort(e.getExtra() != null ? e.getExtra().length : 0);
writeBytes(nameBytes, 0, nameBytes.length);
if (e.getExtra() != null) {
writeBytes(e.getExtra(), 0, e.getExtra().length);
}
locoff = written;
}
/*
* Writes extra data descriptor (EXT) for specified entry.
*/
private void writeEXT(ZipEntry e) throws IOException {
writeInt(EXTSIG); // EXT header signature
writeInt(e.getCrc()); // crc-32
writeInt(e.getCompressedSize()); // compressed size
writeInt(e.getSize()); // uncompressed size
}
/*
* Write central directory (CEN) header for specified entry. REMIND: add
* support for file attributes
*/
private void writeCEN(XEntry xentry) throws IOException {
ZipEntry e = xentry.entry;
int flag = xentry.flag;
int version = version(e);
writeInt(CENSIG); // CEN header signature
writeShort(version); // version made by
writeShort(version); // version needed to extract
writeShort(flag); // general purpose bit flag
writeShort(e.getMethod()); // compression method
writeInt(e.getTime()); // last modification time
writeInt(e.getCrc()); // crc-32
writeInt(e.getCompressedSize()); // compressed size
writeInt(e.getSize()); // uncompressed size
byte[] nameBytes = encoding(e.getName());
writeShort(nameBytes.length);
writeShort(e.getExtra() != null ? e.getExtra().length : 0);
byte[] commentBytes;
if (e.getComment() != null) {
commentBytes = this.encoding(e.getComment());
writeShort(commentBytes.length);
} else {
commentBytes = null;
writeShort(0);
}
writeShort(0); // starting disk number
writeShort(0); // internal file attributes (unused)
writeInt(0); // external file attributes (unused)
writeInt(xentry.offset); // relative offset of local header
writeBytes(nameBytes, 0, nameBytes.length);
if (e.getExtra() != null) {
writeBytes(e.getExtra(), 0, e.getExtra().length);
}
if (commentBytes != null) {
writeBytes(commentBytes, 0, commentBytes.length);
}
}
/*
* Writes end of central directory (END) header.
*/
private void writeEND(long off, long len) throws IOException {
int count = xentries.size();
writeInt(ENDSIG); // END record signature
writeShort(0); // number of this disk
writeShort(0); // central directory start disk
writeShort(count); // number of directory entries on disk
writeShort(count); // total number of directory entries
writeInt(len); // length of central directory
writeInt(off); // offset of central directory
if (comment != null) { // zip file comment
writeShort(comment.length);
writeBytes(comment, 0, comment.length);
} else {
writeShort(0);
}
}
/*
* Writes a 16-bit short to the output stream in little-endian byte order.
*/
private void writeShort(int v) throws IOException {
OutputStream out = this.out;
out.write((v >>> 0) & 0xff);
out.write((v >>> 8) & 0xff);
written += 2;
}
/*
* Writes a 32-bit int to the output stream in little-endian byte order.
*/
private void writeInt(long v) throws IOException {
OutputStream out = this.out;
out.write((int) ((v >>> 0) & 0xff));
out.write((int) ((v >>> 8) & 0xff));
out.write((int) ((v >>> 16) & 0xff));
out.write((int) ((v >>> 24) & 0xff));
written += 4;
}
/*
* Writes an array of bytes to the output stream.
*/
private void writeBytes(byte[] b, int off, int len) throws IOException {
super.out.write(b, off, len);
written += len;
}
}