org.apache.tools.zip
Class ZipOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.FilterOutputStream
          org.apache.tools.zip.ZipOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable

public class ZipOutputStream
extends java.io.FilterOutputStream

Reimplementation of java.util.zip.ZipOutputStream that does handle the extended functionality of this package, especially internal/external file attributes and extra fields with different layouts for local file data and central directory entries.

This class will try to use RandomAccessFile when you know that the output is going to go to a file.

If RandomAccessFile cannot be used, this implementation will use a Data Descriptor to store size and CRC information for DEFLATED entries, this means, you don't need to calculate them yourself. Unfortunately this is not possible for the STORED method, here setting the CRC and uncompressed size information is required before putNextEntry can be called.

Field Summary

protected byte[]	buf This buffer servers as a Deflater.
protected static byte[]	CFH_SIG central file header signature
protected static byte[]	DD_SIG data descriptor signature
protected java.util.zip.Deflater	def This Deflater object is used for output.
static int	DEFAULT_COMPRESSION Default compression level for deflated entries.
static int	DEFLATED Compression method for deflated entries.
protected static byte[]	EOCD_SIG end of central dir signature
protected static byte[]	LFH_SIG local file header signature
static int	STORED Compression method for stored entries.

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

ZipOutputStream(java.io.File file)
Creates a new ZIP OutputStream writing to a File.

ZipOutputStream(java.io.OutputStream out)
Creates a new ZIP OutputStream filtering the underlying stream.

Method 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.
void	close() Closes this output stream and releases any system resources associated with the stream.
void	closeEntry() Writes all necessary data for this entry.
protected void	deflate() Writes next block of compressed data to the output stream.
void	finish() Finishs writing the contents and closes this as well as the underlying stream.
void	flush() Flushes this output stream and forces any buffered output bytes to be written out to the stream.
protected byte[]	getBytes(java.lang.String name) Retrieve the bytes for the given String in the encoding set for this Stream.
java.lang.String	getEncoding() The encoding to use for filenames and the file comment.
boolean	isSeekable() This method indicates whether this archive is writing to a seekable stream (i.e., to a random access file).
void	putNextEntry(ZipEntry ze) Begin writing next entry.
void	setComment(java.lang.String comment) Set the file comment.
void	setEncoding(java.lang.String encoding) The encoding to use for filenames and the file comment.
void	setLevel(int level) Sets the compression level for subsequent entries.
void	setMethod(int method) Sets the default compression method for subsequent entries.
protected static ZipLong	toDosTime(java.util.Date time) Convert a Date object to a DOS date/time field.
protected static byte[]	toDosTime(long t) Convert a Date object to a DOS date/time field.
void	write(byte[] b, int offset, int length) Writes bytes to ZIP entry.
void	write(int b) Writes a single byte to ZIP entry.
protected void	writeCentralDirectoryEnd() Writes the "End of central dir record".
protected void	writeCentralFileHeader(ZipEntry ze) Writes the central file header entry.
protected void	writeDataDescriptor(ZipEntry ze) Writes the data descriptor entry.
protected void	writeLocalFileHeader(ZipEntry ze) Writes the local file header entry
protected void	writeOut(byte[] data) Write bytes to output or random access file.
protected void	writeOut(byte[] data, int offset, int length) Write bytes to output or random access file.

Methods inherited from class java.io.FilterOutputStream

write

Methods inherited from class java.lang.Object

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

Field Detail

DEFLATED

public static final int DEFLATED

Compression method for deflated entries.

Since:

1.1

See Also:

Constant Field Values

DEFAULT_COMPRESSION

public static final int DEFAULT_COMPRESSION

Default compression level for deflated entries.

Since:

Ant 1.7

See Also:

Constant Field Values

STORED

public static final int STORED

Compression method for stored entries.

Since:

1.1

See Also:

Constant Field Values

def

protected java.util.zip.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 DeflaterOutputStream up to Revision 1.13.

Since:

1.14

buf

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 DeflaterOutputStream up to Revision 1.13.

Since:

1.14

LFH_SIG

protected static final byte[] LFH_SIG

local file header signature

Since:

1.1

DD_SIG

protected static final byte[] DD_SIG

data descriptor signature

Since:

1.1

CFH_SIG

protected static final byte[] CFH_SIG

central file header signature

Since:

1.1

EOCD_SIG

protected static final byte[] EOCD_SIG

end of central dir signature

Since:

1.1

Constructor Detail

ZipOutputStream

public ZipOutputStream(java.io.OutputStream out)

Creates a new ZIP OutputStream filtering the underlying stream.

Parameters:

out - the outputstream to zip

Since:

1.1

ZipOutputStream

public ZipOutputStream(java.io.File file)
                throws java.io.IOException

Creates a new ZIP OutputStream writing to a File. Will use random access if possible.

Parameters:

file - the file to zip to

Throws:

java.io.IOException - on error

Since:

1.14

Method Detail

isSeekable

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 STORED entries before invoking putNextEntry(org.apache.tools.zip.ZipEntry).

Returns:

true if seekable

Since:

1.17

setEncoding

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.

Parameters:

encoding - the encoding value

Since:

1.3

getEncoding

public java.lang.String getEncoding()

The encoding to use for filenames and the file comment.

Returns:

null if using the platform's default character encoding.

Since:

1.3

finish

public void finish()
            throws java.io.IOException

Finishs writing the contents and closes this as well as the underlying stream.

Throws:

java.io.IOException - on error

Since:

1.1

closeEntry

public void closeEntry()
                throws java.io.IOException

Writes all necessary data for this entry.

Throws:

java.io.IOException - on error

Since:

1.1

putNextEntry

public void putNextEntry(ZipEntry ze)
                  throws java.io.IOException

Begin writing next entry.

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

Since:

1.1

setComment

public void setComment(java.lang.String comment)

Set the file comment.

Parameters:

comment - the comment

Since:

1.1

setLevel

public void setLevel(int level)

Sets the compression level for subsequent entries.

Default is Deflater.DEFAULT_COMPRESSION.

Parameters:

level - the compression level.

Throws:

java.lang.IllegalArgumentException - if an invalid compression level is specified.

Since:

1.1

setMethod

public void setMethod(int method)

Sets the default compression method for subsequent entries.

Default is DEFLATED.

Parameters:

method - an int from java.util.zip.ZipEntry

Since:

1.1

write

public void write(byte[] b,
                  int offset,
                  int length)
           throws java.io.IOException

Writes bytes to ZIP entry.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - the byte array to write

offset - the start position to write from

length - the number of bytes to write

Throws:

java.io.IOException - on error

write

public void write(int b)
           throws java.io.IOException

Writes a single byte to ZIP entry.

Delegates to the three arg method.

Overrides:

write in class java.io.FilterOutputStream

Parameters:

b - the byte to write

Throws:

java.io.IOException - on error

Since:

1.14

close

public void close()
           throws java.io.IOException

Closes this output stream and releases any system resources associated with the stream.

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.FilterOutputStream

Throws:

java.io.IOException - if an I/O error occurs.

Since:

1.14

flush

public void flush()
           throws java.io.IOException

Flushes this output stream and forces any buffered output bytes to be written out to the stream.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.FilterOutputStream

Throws:

java.io.IOException - if an I/O error occurs.

Since:

1.14

deflate

protected final void deflate()
                      throws java.io.IOException

Writes next block of compressed data to the output stream.

Throws:

java.io.IOException - on error

Since:

1.14

writeLocalFileHeader

protected void writeLocalFileHeader(ZipEntry ze)
                             throws java.io.IOException

Writes the local file header entry

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

Since:

1.1

writeDataDescriptor

protected void writeDataDescriptor(ZipEntry ze)
                            throws java.io.IOException

Writes the data descriptor entry.

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

Since:

1.1

writeCentralFileHeader

protected void writeCentralFileHeader(ZipEntry ze)
                               throws java.io.IOException

Writes the central file header entry.

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

Since:

1.1

writeCentralDirectoryEnd

protected void writeCentralDirectoryEnd()
                                 throws java.io.IOException

Writes the "End of central dir record".

Throws:

java.io.IOException - on error

Since:

1.1

toDosTime

protected static ZipLong toDosTime(java.util.Date time)

Convert a Date object to a DOS date/time field.

Parameters:

time - the Date to convert

Returns:

the date as a ZipLong

Since:

1.1

toDosTime

protected static byte[] toDosTime(long t)

Convert a Date object to a DOS date/time field.

Stolen from InfoZip's fileio.c

Parameters:

t - number of milliseconds since the epoch

Returns:

the date as a byte array

Since:

1.26

getBytes

protected byte[] getBytes(java.lang.String name)
                   throws java.util.zip.ZipException

Retrieve the bytes for the given String in the encoding set for this Stream.

Parameters:

name - the string to get bytes from

Returns:

the bytes as a byte array

Throws:

java.util.zip.ZipException - on error

Since:

1.3

writeOut

protected final void writeOut(byte[] data)
                       throws java.io.IOException

Write bytes to output or random access file.

Parameters:

data - the byte array to write

Throws:

java.io.IOException - on error

Since:

1.14

writeOut

protected final void writeOut(byte[] data,
                              int offset,
                              int length)
                       throws java.io.IOException

Write bytes to output or random access file.

Parameters:

data - the byte array to write

offset - the start position to write from

length - the number of bytes to write

Throws:

java.io.IOException - on error

Since:

1.14

adjustToLong

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.

Parameters:

i - the value to treat as unsigned int.

Returns:

the unsigned int as a long.

Since:

1.34