Module java.base

Package java.util.zip

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

Fields

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

Constructors

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:

• Constant Field Values

DEFLATED

public static final int DEFLATED

Compression method for compressed (DEFLATED) entries.

See Also:

• Constant Field Values

LOCSIG

static final long LOCSIG

Local file (LOC) header signature.

See Also:

• Constant Field Values

EXTSIG

static final long EXTSIG

Extra local (EXT) header signature.

See Also:

• Constant Field Values

CENSIG

static final long CENSIG

Central directory (CEN) header signature.

See Also:

• Constant Field Values

ENDSIG

static final long ENDSIG

End of central directory (END) header signature.

See Also:

• Constant Field Values

LOCHDR

static final int LOCHDR

Local file (LOC) header size in bytes (including signature).

See Also:

• Constant Field Values

EXTHDR

static final int EXTHDR

Extra local (EXT) header size in bytes (including signature).

See Also:

• Constant Field Values

CENHDR

static final int CENHDR

Central directory (CEN) header size in bytes (including signature).

See Also:

• Constant Field Values

ENDHDR

static final int ENDHDR

End of central directory (END) header size in bytes (including signature).

See Also:

• Constant Field Values

LOCVER

static final int LOCVER

Local file (LOC) header version needed to extract field offset.

See Also:

• Constant Field Values

LOCFLG

static final int LOCFLG

Local file (LOC) header general purpose bit flag field offset.

See Also:

• Constant Field Values

LOCHOW

static final int LOCHOW

Local file (LOC) header compression method field offset.

See Also:

• Constant Field Values

LOCTIM

static final int LOCTIM

Local file (LOC) header modification time field offset.

See Also:

• Constant Field Values

LOCCRC

static final int LOCCRC

Local file (LOC) header uncompressed file crc-32 value field offset.

See Also:

• Constant Field Values

LOCSIZ

static final int LOCSIZ

Local file (LOC) header compressed size field offset.

See Also:

• Constant Field Values

LOCLEN

static final int LOCLEN

Local file (LOC) header uncompressed size field offset.

See Also:

• Constant Field Values

LOCNAM

static final int LOCNAM

Local file (LOC) header filename length field offset.

See Also:

• Constant Field Values

LOCEXT

static final int LOCEXT

Local file (LOC) header extra field length field offset.

See Also:

• Constant Field Values

EXTCRC

static final int EXTCRC

Extra local (EXT) header uncompressed file crc-32 value field offset.

See Also:

• Constant Field Values

EXTSIZ

static final int EXTSIZ

Extra local (EXT) header compressed size field offset.

See Also:

• Constant Field Values

EXTLEN

static final int EXTLEN

Extra local (EXT) header uncompressed size field offset.

See Also:

• Constant Field Values

CENVEM

static final int CENVEM

Central directory (CEN) header version made by field offset.

See Also:

• Constant Field Values

CENVER

static final int CENVER

Central directory (CEN) header version needed to extract field offset.

See Also:

• Constant Field Values

CENFLG

static final int CENFLG

Central directory (CEN) header encrypt, decrypt flags field offset.

See Also:

• Constant Field Values

CENHOW

static final int CENHOW

Central directory (CEN) header compression method field offset.

See Also:

• Constant Field Values

CENTIM

static final int CENTIM

Central directory (CEN) header modification time field offset.

See Also:

• Constant Field Values

CENCRC

static final int CENCRC

Central directory (CEN) header uncompressed file crc-32 value field offset.

See Also:

• Constant Field Values

CENSIZ

static final int CENSIZ

Central directory (CEN) header compressed size field offset.

See Also:

• Constant Field Values

CENLEN

static final int CENLEN

Central directory (CEN) header uncompressed size field offset.

See Also:

• Constant Field Values

CENNAM

static final int CENNAM

Central directory (CEN) header filename length field offset.

See Also:

• Constant Field Values

CENEXT

static final int CENEXT

Central directory (CEN) header extra field length field offset.

See Also:

• Constant Field Values

CENCOM

static final int CENCOM

Central directory (CEN) header comment length field offset.

See Also:

• Constant Field Values

CENDSK

static final int CENDSK

Central directory (CEN) header disk number start field offset.

See Also:

• Constant Field Values

CENATT

static final int CENATT

Central directory (CEN) header internal file attributes field offset.

See Also:

• Constant Field Values

CENATX

static final int CENATX

Central directory (CEN) header external file attributes field offset.

See Also:

• Constant Field Values

CENOFF

static final int CENOFF

Central directory (CEN) header LOC header offset field offset.

See Also:

• Constant Field Values

ENDSUB

static final int ENDSUB

End of central directory (END) header number of entries on this disk field offset.

See Also:

• Constant Field Values

ENDTOT

static final int ENDTOT

End of central directory (END) header total number of entries field offset.

See Also:

• Constant Field Values

ENDSIZ

static final int ENDSIZ

End of central directory (END) header central directory size in bytes field offset.

See Also:

• Constant Field Values

ENDOFF

static final int ENDOFF

End of central directory (END) header offset for the first CEN header field offset.

See Also:

• Constant Field Values

ENDCOM

static final int ENDCOM

End of central directory (END) header zip file comment length field offset.

See Also:

• Constant Field Values

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:

• FilterOutputStream.write(int)

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:

• FilterOutputStream.flush()
• FilterOutputStream.out