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/OpenJDK 21

Class ZipOutputStream

java.lang.Object
java.io.OutputStream
java.io.FilterOutputStream
java.util.zip.DeflaterOutputStream
java.util.zip.ZipOutputStream
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
Direct Known Subclasses:
JarOutputStream
public class ZipOutputStream extends DeflaterOutputStream
This class implements an output stream filter for writing files in the ZIP file format. Includes support for both compressed and uncompressed entries.
Since:
1.1

Field Summary

Modifier and Type Field Description
static final int CENATT
Central directory (CEN) header internal file attributes field offset.
static final int CENATX
Central directory (CEN) header external file attributes field offset.
static final int CENCOM
Central directory (CEN) header comment length field offset.
static final int CENCRC
Central directory (CEN) header uncompressed file crc-32 value field offset.
static final int CENDSK
Central directory (CEN) header disk number start field offset.
static final int CENEXT
Central directory (CEN) header extra field length field offset.
static final int CENFLG
Central directory (CEN) header encrypt, decrypt flags field offset.
static final int CENHDR
Central directory (CEN) header size in bytes (including signature).
static final int CENHOW
Central directory (CEN) header compression method field offset.
static final int CENLEN
Central directory (CEN) header uncompressed size field offset.
static final int CENNAM
Central directory (CEN) header filename length field offset.
static final int CENOFF
Central directory (CEN) header LOC header offset field offset.
static final long CENSIG
Central directory (CEN) header signature.
static final int CENSIZ
Central directory (CEN) header compressed size field offset.
static final int CENTIM
Central directory (CEN) header modification time field offset.
static final int CENVEM
Central directory (CEN) header version made by field offset.
static final int CENVER
Central directory (CEN) header version needed to extract field offset.
static final int DEFLATED
Compression method for compressed (DEFLATED) entries.
static final int ENDCOM
End of central directory (END) header zip file comment length field offset.
static final int ENDHDR
End of central directory (END) header size in bytes (including signature).
static final int ENDOFF
End of central directory (END) header offset for the first CEN header field offset.
static final long ENDSIG
End of central directory (END) header signature.
static final int ENDSIZ
End of central directory (END) header central directory size in bytes field offset.
static final int ENDSUB
End of central directory (END) header number of entries on this disk field offset.
static final int ENDTOT
End of central directory (END) header total number of entries field offset.
static final int EXTCRC
Extra local (EXT) header uncompressed file crc-32 value field offset.
static final int EXTHDR
Extra local (EXT) header size in bytes (including signature).
static final int EXTLEN
Extra local (EXT) header uncompressed size field offset.
static final long EXTSIG
Extra local (EXT) header signature.
static final int EXTSIZ
Extra local (EXT) header compressed size field offset.
static final int LOCCRC
Local file (LOC) header uncompressed file crc-32 value field offset.
static final int LOCEXT
Local file (LOC) header extra field length field offset.
static final int LOCFLG
Local file (LOC) header general purpose bit flag field offset.
static final int LOCHDR
Local file (LOC) header size in bytes (including signature).
static final int LOCHOW
Local file (LOC) header compression method field offset.
static final int LOCLEN
Local file (LOC) header uncompressed size field offset.
static final int LOCNAM
Local file (LOC) header filename length field offset.
static final long LOCSIG
Local file (LOC) header signature.
static final int LOCSIZ
Local file (LOC) header compressed size field offset.
static final int LOCTIM
Local file (LOC) header modification time field offset.
static final int LOCVER
Local file (LOC) header version needed to extract field offset.
static final int STORED
Compression method for uncompressed (STORED) entries.

Fields declared in class java.util.zip.DeflaterOutputStream

buf, def

Fields declared in class java.io.FilterOutputStream

out

Constructor Summary

Constructor Description
ZipOutputStream(OutputStream out)
Creates a new ZIP output stream.
ZipOutputStream(OutputStream out, Charset charset)
Creates a new ZIP output stream.

Method Summary

Modifier and Type Method Description
void close()
Closes the ZIP output stream as well as the stream being filtered.
void closeEntry()
Closes the current ZIP entry and positions the stream for writing the next entry.
void finish()
Finishes writing the contents of the ZIP output stream without closing the underlying stream.
void putNextEntry(ZipEntry e)
Begins writing a new ZIP file entry and positions the stream to the start of the entry data.
void setComment(String comment)
Sets the ZIP file comment.
void setLevel(int level)
Sets the compression level for subsequent entries which are DEFLATED.
void setMethod(int method)
Sets the default compression method for subsequent entries.
void write(byte[] b, int off, int len)
Writes an array of bytes to the current ZIP entry data.

Methods declared in class java.util.zip.DeflaterOutputStream

deflate, flush, write

Methods declared in class java.io.FilterOutputStream

write

Methods declared in class java.io.OutputStream

nullOutputStream

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

STORED

public static final int STORED
Compression method for uncompressed (STORED) entries.
See Also:

DEFLATED

public static final int DEFLATED
Compression method for compressed (DEFLATED) entries.
See Also:

LOCSIG

static final long LOCSIG
Local file (LOC) header signature.
See Also:

EXTSIG

static final long EXTSIG
Extra local (EXT) header signature.
See Also:

CENSIG

static final long CENSIG
Central directory (CEN) header signature.
See Also:

ENDSIG

static final long ENDSIG
End of central directory (END) header signature.
See Also:

LOCHDR

static final int LOCHDR
Local file (LOC) header size in bytes (including signature).
See Also:

EXTHDR

static final int EXTHDR
Extra local (EXT) header size in bytes (including signature).
See Also:

CENHDR

static final int CENHDR
Central directory (CEN) header size in bytes (including signature).
See Also:

ENDHDR

static final int ENDHDR
End of central directory (END) header size in bytes (including signature).
See Also:

LOCVER

static final int LOCVER
Local file (LOC) header version needed to extract field offset.
See Also:

LOCFLG

static final int LOCFLG
Local file (LOC) header general purpose bit flag field offset.
See Also:

LOCHOW

static final int LOCHOW
Local file (LOC) header compression method field offset.
See Also:

LOCTIM

static final int LOCTIM
Local file (LOC) header modification time field offset.
See Also:

LOCCRC

static final int LOCCRC
Local file (LOC) header uncompressed file crc-32 value field offset.
See Also:

LOCSIZ

static final int LOCSIZ
Local file (LOC) header compressed size field offset.
See Also:

LOCLEN

static final int LOCLEN
Local file (LOC) header uncompressed size field offset.
See Also:

LOCNAM

static final int LOCNAM
Local file (LOC) header filename length field offset.
See Also:

LOCEXT

static final int LOCEXT
Local file (LOC) header extra field length field offset.
See Also:

EXTCRC

static final int EXTCRC
Extra local (EXT) header uncompressed file crc-32 value field offset.
See Also:

EXTSIZ

static final int EXTSIZ
Extra local (EXT) header compressed size field offset.
See Also:

EXTLEN

static final int EXTLEN
Extra local (EXT) header uncompressed size field offset.
See Also:

CENVEM

static final int CENVEM
Central directory (CEN) header version made by field offset.
See Also:

CENVER

static final int CENVER
Central directory (CEN) header version needed to extract field offset.
See Also:

CENFLG

static final int CENFLG
Central directory (CEN) header encrypt, decrypt flags field offset.
See Also:

CENHOW

static final int CENHOW
Central directory (CEN) header compression method field offset.
See Also:

CENTIM

static final int CENTIM
Central directory (CEN) header modification time field offset.
See Also:

CENCRC

static final int CENCRC
Central directory (CEN) header uncompressed file crc-32 value field offset.
See Also:

CENSIZ

static final int CENSIZ
Central directory (CEN) header compressed size field offset.
See Also:

CENLEN

static final int CENLEN
Central directory (CEN) header uncompressed size field offset.
See Also:

CENNAM

static final int CENNAM
Central directory (CEN) header filename length field offset.
See Also:

CENEXT

static final int CENEXT
Central directory (CEN) header extra field length field offset.
See Also:

CENCOM

static final int CENCOM
Central directory (CEN) header comment length field offset.
See Also:

CENDSK

static final int CENDSK
Central directory (CEN) header disk number start field offset.
See Also:

CENATT

static final int CENATT
Central directory (CEN) header internal file attributes field offset.
See Also:

CENATX

static final int CENATX
Central directory (CEN) header external file attributes field offset.
See Also:

CENOFF

static final int CENOFF
Central directory (CEN) header LOC header offset field offset.
See Also:

ENDSUB

static final int ENDSUB
End of central directory (END) header number of entries on this disk field offset.
See Also:

ENDTOT

static final int ENDTOT
End of central directory (END) header total number of entries field offset.
See Also:

ENDSIZ

static final int ENDSIZ
End of central directory (END) header central directory size in bytes field offset.
See Also:

ENDOFF

static final int ENDOFF
End of central directory (END) header offset for the first CEN header field offset.
See Also:

ENDCOM

static final int ENDCOM
End of central directory (END) header zip file comment length field offset.
See Also:

Constructor Details

ZipOutputStream

public ZipOutputStream(OutputStream out)
Creates a new ZIP output stream.

The UTF-8 charset is used to encode the entry names and comments.

Parameters:
out - the actual output stream

ZipOutputStream

public ZipOutputStream(OutputStream out, Charset charset)
Creates a new ZIP output stream.
Parameters:
out - the actual output stream
charset - the charset to be used to encode the entry names and comments
Since:
1.7

Method Details

setComment

public void setComment(String comment)
Sets the ZIP file comment.
Parameters:
comment - the comment string
Throws:
IllegalArgumentException - if the length of the specified ZIP file comment is greater than 0xFFFF bytes

setMethod

public void setMethod(int method)
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.
Parameters:
method - the default compression method
Throws:
IllegalArgumentException - if the specified compression method is invalid

setLevel

public void setLevel(int level)
Sets the compression level for subsequent entries which are DEFLATED. The default setting is DEFAULT_COMPRESSION.
Parameters:
level - the compression level (0-9)
Throws:
IllegalArgumentException - if the compression level is invalid

putNextEntry

public void putNextEntry(ZipEntry e) throws IOException
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. When writing a compressed (DEFLATED) entry, and the compressed size has not been explicitly set with the ZipEntry.setCompressedSize(long) method, then the compressed size will be set to the actual compressed size after deflation.

The current time will be used if the entry has no set modification time.

API Note:
When writing a directory entry, the STORED compression method should be used and the size and CRC-32 values should be set to 0: 
     ZipEntry e = new ZipEntry(entryName);
     if (e.isDirectory()) {
         e.setMethod(ZipEntry.STORED);
         e.setSize(0);
         e.setCrc(0);
     }
     stream.putNextEntry(e);
This allows optimal performance when processing directory entries.
Parameters:
e - the ZIP entry to be written
Throws:
ZipException - if a ZIP format error has occurred
IOException - if an I/O error has occurred

closeEntry

public void closeEntry() throws IOException
Closes the current ZIP entry and positions the stream for writing the next entry.
Throws:
ZipException - if a ZIP format error has occurred
IOException - if an I/O error has occurred

write

public void write(byte[] b, int off, int len) throws IOException
Writes an array of bytes to the current ZIP entry data. This method will block until all the bytes are written.
Overrides:
write in class DeflaterOutputStream
Parameters:
b - the data to be written
off - the start offset in the data
len - the number of bytes that are written
Throws:
ZipException - if a ZIP file error has occurred
IOException - if an I/O error has occurred
See Also:

finish

public void finish() throws IOException
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.
Overrides:
finish in class DeflaterOutputStream
Throws:
ZipException - if a ZIP file error has occurred
IOException - if an I/O exception has occurred

close

public void close() throws IOException
Closes the ZIP output stream as well as the stream being filtered.
Specified by:
close in interface AutoCloseable
Specified by:
close in interface Closeable
Overrides:
close in class DeflaterOutputStream
Throws:
ZipException - if a ZIP file error has occurred
IOException - if an I/O error has occurred
See Also:

© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/zip/ZipOutputStream.html