/*
* 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 java.util.zip;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charsets;
import java.util.Arrays;
import java.util.HashSet;
/**
* This class provides an implementation of {@code FilterOutputStream} that
* compresses data entries into a <i>ZIP-archive</i> output stream.
* <p>
* {@code ZipOutputStream} is used to write {@code ZipEntries} to the underlying
* stream. Output from {@code ZipOutputStream} conforms to the {@code ZipFile}
* file format.
* <p>
* While {@code DeflaterOutputStream} can write a compressed <i>ZIP-archive</i>
* entry, this extension can write uncompressed entries as well. In this case
* special rules apply, for this purpose refer to the <a
* href="http://www.pkware.com/documents/casestudies/APPNOTE.TXT">file format
* specification</a>.
*
* <h3>Example</h3>
* <p>Using {@code ZipOutputStream} is a little more complicated than {@link GZIPOutputStream}
* because ZIP archives are containers that can contain multiple files. This code creates a ZIP
* archive containing several files, similar to the {@code zip(1)} utility.
* <pre>
* OutputStream os = ...
* ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(os));
* try {
* for (int i = 0; i < fileCount; ++i) {
* String filename = ...
* byte[] bytes = ...
* ZipEntry entry = new ZipEntry(filename);
* zos.putNextEntry(entry);
* zos.write(bytes);
* zos.closeEntry();
* }
* } finally {
* zos.close();
* }
* </pre>
*
* @see ZipEntry
* @see ZipFile
*/
public class ZipOutputStream extends DeflaterOutputStream implements ZipConstants {
/**
* Indicates deflated entries.
*/
public static final int DEFLATED = 8;
/**
* Indicates uncompressed entries.
*/
public static final int STORED = 0;
private static final int ZIPLocalHeaderVersionNeeded = 20;
private String comment;
private final HashSet<String> entries = new HashSet<String>();
private int compressMethod = DEFLATED;
private int compressLevel = Deflater.DEFAULT_COMPRESSION;
private ByteArrayOutputStream cDir = new ByteArrayOutputStream();
private ZipEntry currentEntry;
private final CRC32 crc = new CRC32();
private int offset = 0, curOffset = 0, nameLength;
private byte[] nameBytes;
/**
* Constructs a new {@code ZipOutputStream} with the specified output
* stream.
*
* @param p1
* the {@code OutputStream} to write the data to.
*/
public ZipOutputStream(OutputStream p1) {
super(p1, new Deflater(Deflater.DEFAULT_COMPRESSION, true));
}
/**
* Closes the current {@code ZipEntry}, if any, and the underlying output
* stream. If the stream is already closed this method does nothing.
*
* @throws IOException
* If an error occurs closing the stream.
*/
@Override
public void close() throws IOException {
// don't call super.close() because that calls finish() conditionally
if (out != null) {
finish();
def.end();
out.close();
out = null;
}
}
/**
* Closes the current {@code ZipEntry}. Any entry terminal data is written
* to the underlying stream.
*
* @throws IOException
* If an error occurs closing the entry.
*/
public void closeEntry() throws IOException {
checkClosed();
if (currentEntry == null) {
return;
}
if (currentEntry.getMethod() == DEFLATED) {
super.finish();
}
// Verify values for STORED types
if (currentEntry.getMethod() == STORED) {
if (crc.getValue() != currentEntry.crc) {
throw new ZipException("CRC mismatch");
}
if (currentEntry.size != crc.tbytes) {
throw new ZipException("Size mismatch");
}
}
curOffset = LOCHDR;
// Write the DataDescriptor
if (currentEntry.getMethod() != STORED) {
curOffset += EXTHDR;
writeLong(out, EXTSIG);
writeLong(out, currentEntry.crc = crc.getValue());
writeLong(out, currentEntry.compressedSize = def.getTotalOut());
writeLong(out, currentEntry.size = def.getTotalIn());
}
// Update the CentralDirectory
// http://www.pkware.com/documents/casestudies/APPNOTE.TXT
int flags = currentEntry.getMethod() == STORED ? 0 : ZipFile.GPBF_DATA_DESCRIPTOR_FLAG;
// Since gingerbread, we always set the UTF-8 flag on individual files.
// Some tools insist that the central directory also have the UTF-8 flag.
// http://code.google.com/p/android/issues/detail?id=20214
flags |= ZipFile.GPBF_UTF8_FLAG;
writeLong(cDir, CENSIG);
writeShort(cDir, ZIPLocalHeaderVersionNeeded); // Version created
writeShort(cDir, ZIPLocalHeaderVersionNeeded); // Version to extract
writeShort(cDir, flags);
writeShort(cDir, currentEntry.getMethod());
writeShort(cDir, currentEntry.time);
writeShort(cDir, currentEntry.modDate);
writeLong(cDir, crc.getValue());
if (currentEntry.getMethod() == DEFLATED) {
curOffset += writeLong(cDir, def.getTotalOut());
writeLong(cDir, def.getTotalIn());
} else {
curOffset += writeLong(cDir, crc.tbytes);
writeLong(cDir, crc.tbytes);
}
curOffset += writeShort(cDir, nameLength);
if (currentEntry.extra != null) {
curOffset += writeShort(cDir, currentEntry.extra.length);
} else {
writeShort(cDir, 0);
}
String c;
if ((c = currentEntry.getComment()) != null) {
writeShort(cDir, c.length());
} else {
writeShort(cDir, 0);
}
writeShort(cDir, 0); // Disk Start
writeShort(cDir, 0); // Internal File Attributes
writeLong(cDir, 0); // External File Attributes
writeLong(cDir, offset);
cDir.write(nameBytes);
nameBytes = null;
if (currentEntry.extra != null) {
cDir.write(currentEntry.extra);
}
offset += curOffset;
if (c != null) {
cDir.write(c.getBytes());
}
currentEntry = null;
crc.reset();
def.reset();
done = false;
}
/**
* Indicates that all entries have been written to the stream. Any terminal
* information is written to the underlying stream.
*
* @throws IOException
* if an error occurs while terminating the stream.
*/
@Override
public void finish() throws IOException {
// TODO: is there a bug here? why not checkClosed?
if (out == null) {
throw new IOException("Stream is closed");
}
if (cDir == null) {
return;
}
if (entries.isEmpty()) {
throw new ZipException("No entries");
}
if (currentEntry != null) {
closeEntry();
}
int cdirSize = cDir.size();
// Write Central Dir End
writeLong(cDir, ENDSIG);
writeShort(cDir, 0); // Disk Number
writeShort(cDir, 0); // Start Disk
writeShort(cDir, entries.size()); // Number of entries
writeShort(cDir, entries.size()); // Number of entries
writeLong(cDir, cdirSize); // Size of central dir
writeLong(cDir, offset); // Offset of central dir
if (comment != null) {
writeShort(cDir, comment.length());
cDir.write(comment.getBytes());
} else {
writeShort(cDir, 0);
}
// Write the central directory.
cDir.writeTo(out);
cDir = null;
}
/**
* Writes entry information to the underlying stream. Data associated with
* the entry can then be written using {@code write()}. After data is
* written {@code closeEntry()} must be called to complete the writing of
* the entry to the underlying stream.
*
* @param ze
* the {@code ZipEntry} to store.
* @throws IOException
* If an error occurs storing the entry.
* @see #write
*/
public void putNextEntry(ZipEntry ze) throws IOException {
if (currentEntry != null) {
closeEntry();
}
if (ze.getMethod() == STORED || (compressMethod == STORED && ze.getMethod() == -1)) {
if (ze.crc == -1) {
throw new ZipException("CRC mismatch");
}
if (ze.size == -1 && ze.compressedSize == -1) {
throw new ZipException("Size mismatch");
}
if (ze.size != ze.compressedSize && ze.compressedSize != -1 && ze.size != -1) {
throw new ZipException("Size mismatch");
}
}
checkClosed();
if (entries.contains(ze.name)) {
throw new ZipException("Entry already exists: " + ze.name);
}
if (entries.size() == 64*1024-1) {
// TODO: support Zip64.
throw new ZipException("Too many entries for the zip file format's 16-bit entry count");
}
nameBytes = ze.name.getBytes(Charsets.UTF_8);
nameLength = nameBytes.length;
if (nameLength > 0xffff) {
throw new IllegalArgumentException("Name too long: " + nameLength + " UTF-8 bytes");
}
def.setLevel(compressLevel);
currentEntry = ze;
entries.add(currentEntry.name);
if (currentEntry.getMethod() == -1) {
currentEntry.setMethod(compressMethod);
}
// Local file header.
// http://www.pkware.com/documents/casestudies/APPNOTE.TXT
int flags = currentEntry.getMethod() == STORED ? 0 : ZipFile.GPBF_DATA_DESCRIPTOR_FLAG;
// Java always outputs UTF-8 filenames. (Before Java 7, the RI didn't set this flag and used
// modified UTF-8. From Java 7, it sets this flag and uses normal UTF-8.)
flags |= ZipFile.GPBF_UTF8_FLAG;
writeLong(out, LOCSIG); // Entry header
writeShort(out, ZIPLocalHeaderVersionNeeded); // Extraction version
writeShort(out, flags);
writeShort(out, currentEntry.getMethod());
if (currentEntry.getTime() == -1) {
currentEntry.setTime(System.currentTimeMillis());
}
writeShort(out, currentEntry.time);
writeShort(out, currentEntry.modDate);
if (currentEntry.getMethod() == STORED) {
if (currentEntry.size == -1) {
currentEntry.size = currentEntry.compressedSize;
} else if (currentEntry.compressedSize == -1) {
currentEntry.compressedSize = currentEntry.size;
}
writeLong(out, currentEntry.crc);
writeLong(out, currentEntry.size);
writeLong(out, currentEntry.size);
} else {
writeLong(out, 0);
writeLong(out, 0);
writeLong(out, 0);
}
writeShort(out, nameLength);
if (currentEntry.extra != null) {
writeShort(out, currentEntry.extra.length);
} else {
writeShort(out, 0);
}
out.write(nameBytes);
if (currentEntry.extra != null) {
out.write(currentEntry.extra);
}
}
/**
* Sets the {@code ZipFile} comment associated with the file being written.
*
* @param comment
* the comment associated with the file.
*/
public void setComment(String comment) {
if (comment.length() > 0xFFFF) {
throw new IllegalArgumentException("Comment too long: " + comment.length() + " characters");
}
this.comment = comment;
}
/**
* Sets the compression level to be used for writing entry data. This level
* may be set on a per entry basis. The level must have a value between -1
* and 8 according to the {@code Deflater} compression level bounds.
*
* @param level
* the compression level (ranging from -1 to 8).
* @see Deflater
*/
public void setLevel(int level) {
if (level < Deflater.DEFAULT_COMPRESSION || level > Deflater.BEST_COMPRESSION) {
throw new IllegalArgumentException();
}
compressLevel = level;
}
/**
* Sets the compression method to be used when compressing entry data.
* method must be one of {@code STORED} (for no compression) or {@code
* DEFLATED}.
*
* @param method
* the compression method to use.
*/
public void setMethod(int method) {
if (method != STORED && method != DEFLATED) {
throw new IllegalArgumentException();
}
compressMethod = method;
}
private long writeLong(OutputStream os, long i) throws IOException {
// Write out the long value as an unsigned int
os.write((int) (i & 0xFF));
os.write((int) (i >> 8) & 0xFF);
os.write((int) (i >> 16) & 0xFF);
os.write((int) (i >> 24) & 0xFF);
return i;
}
private int writeShort(OutputStream os, int i) throws IOException {
os.write(i & 0xFF);
os.write((i >> 8) & 0xFF);
return i;
}
/**
* Writes data for the current entry to the underlying stream.
*
* @exception IOException
* If an error occurs writing to the stream
*/
@Override
public void write(byte[] buffer, int offset, int byteCount) throws IOException {
Arrays.checkOffsetAndCount(buffer.length, offset, byteCount);
if (currentEntry == null) {
throw new ZipException("No active entry");
}
if (currentEntry.getMethod() == STORED) {
out.write(buffer, offset, byteCount);
} else {
super.write(buffer, offset, byteCount);
}
crc.update(buffer, offset, byteCount);
}
private void checkClosed() throws IOException {
if (cDir == null) {
throw new IOException("Stream is closed");
}
}
}