File	Doc	Category	Size	Date	Package
ZipOutputStream.java	API Doc	Apache Ant 1.70	25348	Wed Dec 13 06:16:20 GMT 2006	org.apache.tools.zip

ZipOutputStream

• java.lang.Object
  • java.io.OutputStream
    • java.io.FilterOutputStream

Fields Summary
public static final int	DEFLATED Compression method for deflated entries.
public static final int	DEFAULT_COMPRESSION Default compression level for deflated entries.
public static final int	STORED Compression method for stored entries.
private ZipEntry	entry Current entry.
private String	comment The file comment.
private int	level Compression level for next entry.
private boolean	hasCompressionLevelChanged Has the compression level changed when compared to the last entry?
private int	method Default compression method for next entry.
private Vector	entries List of ZipEntries written so far.
private CRC32	crc CRC instance to avoid parsing DEFLATED data twice.
private long	written Count the bytes written to out.
private long	dataStart Data for local header data
private long	localDataStart Offset for CRC entry in the local file header data for the current entry starts here.
private long	cdOffset Start of central directory.
private long	cdLength Length of central directory.
private static final byte[]	ZERO Helper, a 0 as ZipShort.
private static final byte[]	LZERO Helper, a 0 as ZipLong.
private Hashtable	offsets Holds the offsets of the LFH starts for each entry.
private String	encoding The encoding to use for filenames and the file comment. For a list of possible values see http://java.sun.com/j2se/1.5.0/docs/guide/intl/encoding.doc.html. Defaults to the platform's default character encoding.
protected Deflater	def This Deflater object is used for output. This attribute is only protected to provide a level of API backwards compatibility. This class used to extend {@link java.util.zip.DeflaterOutputStream DeflaterOutputStream} up to Revision 1.13.
protected byte[]	buf This buffer servers as a Deflater. This attribute is only protected to provide a level of API backwards compatibility. This class used to extend {@link java.util.zip.DeflaterOutputStream DeflaterOutputStream} up to Revision 1.13.
private RandomAccessFile	raf Optional random access output.
protected static final byte[]	LFH_SIG local file header signature
protected static final byte[]	DD_SIG data descriptor signature
protected static final byte[]	CFH_SIG central file header signature
protected static final byte[]	EOCD_SIG end of central dir signature
private static final byte[]	DOS_TIME_MIN Smallest date/time ZIP can handle.

Constructors Summary
public ZipOutputStream(OutputStream out) Creates a new ZIP OutputStream filtering the underlying stream. param out the outputstream to zip since 1.1 super(out);
public ZipOutputStream(File file) Creates a new ZIP OutputStream writing to a File. Will use random access if possible. param file the file to zip to since 1.14 throws IOException on error super(null); try { raf = new RandomAccessFile(file, "rw"); raf.setLength(0); } catch (IOException e) { if (raf != null) { try { raf.close(); } catch (IOException inner) { // ignore } raf = null; } out = new FileOutputStream(file); }

Methods Summary
protected static long	adjustToLong(int i) Assumes a negative integer really is a positive integer that has wrapped around and re-creates the original value. param i the value to treat as unsigned int. return the unsigned int as a long. since 1.34 if (i < 0) { return 2 * ((long) Integer.MAX_VALUE) + 2 + i; } else { return i; }
public void	close() Closes this output stream and releases any system resources associated with the stream. exception IOException if an I/O error occurs. since 1.14 finish(); if (raf != null) { raf.close(); } if (out != null) { out.close(); }
public void	closeEntry() Writes all necessary data for this entry. since 1.1 throws IOException on error if (entry == null) { return; } long realCrc = crc.getValue(); crc.reset(); if (entry.getMethod() == DEFLATED) { def.finish(); while (!def.finished()) { deflate(); } entry.setSize(adjustToLong(def.getTotalIn())); entry.setCompressedSize(adjustToLong(def.getTotalOut())); entry.setCrc(realCrc); def.reset(); written += entry.getCompressedSize(); } else if (raf == null) { if (entry.getCrc() != realCrc) { throw new ZipException("bad CRC checksum for entry " + entry.getName() + ": " + Long.toHexString(entry.getCrc()) + " instead of " + Long.toHexString(realCrc)); } if (entry.getSize() != written - dataStart) { throw new ZipException("bad size for entry " + entry.getName() + ": " + entry.getSize() + " instead of " + (written - dataStart)); } } else { /* method is STORED and we used RandomAccessFile */ long size = written - dataStart; entry.setSize(size); entry.setCompressedSize(size); entry.setCrc(realCrc); } // If random access output, write the local file header containing // the correct CRC and compressed/uncompressed sizes if (raf != null) { long save = raf.getFilePointer(); raf.seek(localDataStart); writeOut(ZipLong.getBytes(entry.getCrc())); writeOut(ZipLong.getBytes(entry.getCompressedSize())); writeOut(ZipLong.getBytes(entry.getSize())); raf.seek(save); } writeDataDescriptor(entry); entry = null;
protected final void	deflate() Writes next block of compressed data to the output stream. throws IOException on error since 1.14 int len = def.deflate(buf, 0, buf.length); if (len > 0) { writeOut(buf, 0, len); }
public void	finish() Finishs writing the contents and closes this as well as the underlying stream. since 1.1 throws IOException on error closeEntry(); cdOffset = written; for (int i = 0, entriesSize = entries.size(); i < entriesSize; i++) { writeCentralFileHeader((ZipEntry) entries.elementAt(i)); } cdLength = written - cdOffset; writeCentralDirectoryEnd(); offsets.clear(); entries.removeAllElements();
public void	flush() Flushes this output stream and forces any buffered output bytes to be written out to the stream. exception IOException if an I/O error occurs. since 1.14 if (out != null) { out.flush(); }
protected byte[]	getBytes(java.lang.String name) Retrieve the bytes for the given String in the encoding set for this Stream. param name the string to get bytes from return the bytes as a byte array throws ZipException on error since 1.3 if (encoding == null) { return name.getBytes(); } else { try { return name.getBytes(encoding); } catch (UnsupportedEncodingException uee) { throw new ZipException(uee.getMessage()); } }
public java.lang.String	getEncoding() The encoding to use for filenames and the file comment. return null if using the platform's default character encoding. since 1.3 return encoding;
public boolean	isSeekable() This method indicates whether this archive is writing to a seekable stream (i.e., to a random access file). For seekable streams, you don't need to calculate the CRC or uncompressed size for {@link #STORED} entries before invoking {@link #putNextEntry}. return true if seekable since 1.17 return raf != null;
public void	putNextEntry(ZipEntry ze) Begin writing next entry. param ze the entry to write since 1.1 throws IOException on error closeEntry(); entry = ze; entries.addElement(entry); if (entry.getMethod() == -1) { // not specified entry.setMethod(method); } if (entry.getTime() == -1) { // not specified entry.setTime(System.currentTimeMillis()); } // Size/CRC not required if RandomAccessFile is used if (entry.getMethod() == STORED && raf == null) { if (entry.getSize() == -1) { throw new ZipException("uncompressed size is required for" + " STORED method when not writing to a" + " file"); } if (entry.getCrc() == -1) { throw new ZipException("crc checksum is required for STORED" + " method when not writing to a file"); } entry.setCompressedSize(entry.getSize()); } if (entry.getMethod() == DEFLATED && hasCompressionLevelChanged) { def.setLevel(level); hasCompressionLevelChanged = false; } writeLocalFileHeader(entry);
public void	setComment(java.lang.String comment) Set the file comment. param comment the comment since 1.1 this.comment = comment;
public void	setEncoding(java.lang.String encoding) The encoding to use for filenames and the file comment. For a list of possible values see http://java.sun.com/j2se/1.5.0/docs/guide/intl/encoding.doc.html. Defaults to the platform's default character encoding. param encoding the encoding value since 1.3 this.encoding = encoding;
public void	setLevel(int level) Sets the compression level for subsequent entries. Default is Deflater.DEFAULT_COMPRESSION. param level the compression level. throws IllegalArgumentException if an invalid compression level is specified. since 1.1 if (level < Deflater.DEFAULT_COMPRESSION || level > Deflater.BEST_COMPRESSION) { throw new IllegalArgumentException( "Invalid compression level: " + level); } hasCompressionLevelChanged = (this.level != level); this.level = level;
public void	setMethod(int method) Sets the default compression method for subsequent entries. Default is DEFLATED. param method an int from java.util.zip.ZipEntry since 1.1 this.method = method;
protected static ZipLong	toDosTime(java.util.Date time) Convert a Date object to a DOS date/time field. param time the Date to convert return the date as a ZipLong since 1.1 return new ZipLong(toDosTime(time.getTime()));
protected static byte[]	toDosTime(long t) Convert a Date object to a DOS date/time field. Stolen from InfoZip's fileio.c param t number of milliseconds since the epoch return the date as a byte array since 1.26 Date time = new Date(t); int year = time.getYear() + 1900; if (year < 1980) { return DOS_TIME_MIN; } int month = time.getMonth() + 1; long value = ((year - 1980) << 25) | (month << 21) | (time.getDate() << 16) | (time.getHours() << 11) | (time.getMinutes() << 5) | (time.getSeconds() >> 1); return ZipLong.getBytes(value);
public void	write(byte[] b, int offset, int length) Writes bytes to ZIP entry. param b the byte array to write param offset the start position to write from param length the number of bytes to write throws IOException on error if (entry.getMethod() == DEFLATED) { if (length > 0) { if (!def.finished()) { def.setInput(b, offset, length); while (!def.needsInput()) { deflate(); } } } } else { writeOut(b, offset, length); written += length; } crc.update(b, offset, length);
public void	write(int b) Writes a single byte to ZIP entry. Delegates to the three arg method. param b the byte to write since 1.14 throws IOException on error byte[] buff = new byte[1]; buff[0] = (byte) (b & 0xff); write(buff, 0, 1);
protected void	writeCentralDirectoryEnd() Writes the "End of central dir record". throws IOException on error since 1.1 writeOut(EOCD_SIG); // disk numbers writeOut(ZERO); writeOut(ZERO); // number of entries byte[] num = ZipShort.getBytes(entries.size()); writeOut(num); writeOut(num); // length and location of CD writeOut(ZipLong.getBytes(cdLength)); writeOut(ZipLong.getBytes(cdOffset)); // ZIP file comment byte[] data = getBytes(comment); writeOut(ZipShort.getBytes(data.length)); writeOut(data);
protected void	writeCentralFileHeader(ZipEntry ze) Writes the central file header entry. param ze the entry to write throws IOException on error since 1.1 writeOut(CFH_SIG); written += 4; // version made by writeOut(ZipShort.getBytes((ze.getPlatform() << 8) | 20)); written += 2; // version needed to extract // general purpose bit flag if (ze.getMethod() == DEFLATED && raf == null) { // requires version 2 as we are going to store length info // in the data descriptor writeOut(ZipShort.getBytes(20)); // bit3 set to signal, we use a data descriptor writeOut(ZipShort.getBytes(8)); } else { writeOut(ZipShort.getBytes(10)); writeOut(ZERO); } written += 4; // compression method writeOut(ZipShort.getBytes(ze.getMethod())); written += 2; // last mod. time and date writeOut(toDosTime(ze.getTime())); written += 4; // CRC // compressed length // uncompressed length writeOut(ZipLong.getBytes(ze.getCrc())); writeOut(ZipLong.getBytes(ze.getCompressedSize())); writeOut(ZipLong.getBytes(ze.getSize())); written += 12; // file name length byte[] name = getBytes(ze.getName()); writeOut(ZipShort.getBytes(name.length)); written += 2; // extra field length byte[] extra = ze.getCentralDirectoryExtra(); writeOut(ZipShort.getBytes(extra.length)); written += 2; // file comment length String comm = ze.getComment(); if (comm == null) { comm = ""; } byte[] commentB = getBytes(comm); writeOut(ZipShort.getBytes(commentB.length)); written += 2; // disk number start writeOut(ZERO); written += 2; // internal file attributes writeOut(ZipShort.getBytes(ze.getInternalAttributes())); written += 2; // external file attributes writeOut(ZipLong.getBytes(ze.getExternalAttributes())); written += 4; // relative offset of LFH writeOut((byte[]) offsets.get(ze)); written += 4; // file name writeOut(name); written += name.length; // extra field writeOut(extra); written += extra.length; // file comment writeOut(commentB); written += commentB.length;
protected void	writeDataDescriptor(ZipEntry ze) Writes the data descriptor entry. param ze the entry to write throws IOException on error since 1.1 if (ze.getMethod() != DEFLATED || raf != null) { return; } writeOut(DD_SIG); writeOut(ZipLong.getBytes(entry.getCrc())); writeOut(ZipLong.getBytes(entry.getCompressedSize())); writeOut(ZipLong.getBytes(entry.getSize())); written += 16;
protected void	writeLocalFileHeader(ZipEntry ze) Writes the local file header entry param ze the entry to write throws IOException on error since 1.1 offsets.put(ze, ZipLong.getBytes(written)); writeOut(LFH_SIG); written += 4; //store method in local variable to prevent multiple method calls final int zipMethod = ze.getMethod(); // version needed to extract // general purpose bit flag if (zipMethod == DEFLATED && raf == null) { // requires version 2 as we are going to store length info // in the data descriptor writeOut(ZipShort.getBytes(20)); // bit3 set to signal, we use a data descriptor writeOut(ZipShort.getBytes(8)); } else { writeOut(ZipShort.getBytes(10)); writeOut(ZERO); } written += 4; // compression method writeOut(ZipShort.getBytes(zipMethod)); written += 2; // last mod. time and date writeOut(toDosTime(ze.getTime())); written += 4; // CRC // compressed length // uncompressed length localDataStart = written; if (zipMethod == DEFLATED || raf != null) { writeOut(LZERO); writeOut(LZERO); writeOut(LZERO); } else { writeOut(ZipLong.getBytes(ze.getCrc())); writeOut(ZipLong.getBytes(ze.getSize())); writeOut(ZipLong.getBytes(ze.getSize())); } written += 12; // file name length byte[] name = getBytes(ze.getName()); writeOut(ZipShort.getBytes(name.length)); written += 2; // extra field length byte[] extra = ze.getLocalFileDataExtra(); writeOut(ZipShort.getBytes(extra.length)); written += 2; // file name writeOut(name); written += name.length; // extra field writeOut(extra); written += extra.length; dataStart = written;
protected final void	writeOut(byte[] data) Write bytes to output or random access file. param data the byte array to write throws IOException on error since 1.14 writeOut(data, 0, data.length);
protected final void	writeOut(byte[] data, int offset, int length) Write bytes to output or random access file. param data the byte array to write param offset the start position to write from param length the number of bytes to write throws IOException on error since 1.14 if (raf != null) { raf.write(data, offset, length); } else { out.write(data, offset, length); }