org.apache.commons.compress.archivers.zip
Class ZipArchiveOutputStream

java.lang.Object
  java.io.OutputStream
      org.apache.commons.compress.archivers.ArchiveOutputStream
          org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable

Direct Known Subclasses:

JarArchiveOutputStream

public class ZipArchiveOutputStream
extends ArchiveOutputStream

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 putArchiveEntry(ArchiveEntry) can be called.

Nested Class Summary

static class

ZipArchiveOutputStream.UnicodeExtraFieldPolicy enum that represents the possible policies for creating Unicode extra fields.

Field Summary

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.
static int	EFS_FLAG General purpose flag, which indicates that filenames are written in utf-8.
protected boolean	finished indicates if this archive is finished.
static int	STORED Compression method for stored entries.

Constructor Summary

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

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

Method Summary

void	close() Closes this output stream and releases any system resources associated with the stream.
void	closeArchiveEntry() Writes all necessary data for this entry.
ArchiveEntry	createArchiveEntry(java.io.File inputFile, java.lang.String entryName) Create an archive entry using the inputFile and entryName provided.
protected void	deflate() Writes next block of compressed data to the output stream.
void	finish() Finishes the addition of entries to this stream, without closing it.
void	flush() Flushes this output stream and forces any buffered output bytes to be written out to the 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	putArchiveEntry(ArchiveEntry archiveEntry) Writes the headers for an archive entry to the output stream.
void	setComment(java.lang.String comment) Set the file comment.
void	setCreateUnicodeExtraFields(ZipArchiveOutputStream.UnicodeExtraFieldPolicy b) Whether to create Unicode Extra Fields.
void	setEncoding(java.lang.String encoding) The encoding to use for filenames and the file comment.
void	setFallbackToUTF8(boolean b) Whether to fall back to UTF and the language encoding flag if the file name cannot be encoded using the specified encoding.
void	setLevel(int level) Sets the compression level for subsequent entries.
void	setMethod(int method) Sets the default compression method for subsequent entries.
void	setUseLanguageEncodingFlag(boolean b) Whether to set the language encoding flag if the file name encoding is UTF-8.
void	write(byte[] b, int offset, int length) Writes bytes to ZIP entry.
protected void	writeCentralDirectoryEnd() Writes the "End of central dir record".
protected void	writeCentralFileHeader(ZipArchiveEntry ze) Writes the central file header entry.
protected void	writeDataDescriptor(ZipArchiveEntry ze) Writes the data descriptor entry.
protected void	writeLocalFileHeader(ZipArchiveEntry 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 org.apache.commons.compress.archivers.ArchiveOutputStream

count, getCount, write

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Field Detail

finished

protected boolean finished

indicates if this archive is finished. protected for use in Jar implementation

DEFLATED

public static final int DEFLATED

Compression method for deflated entries.

See Also:

Constant Field Values

DEFAULT_COMPRESSION

public static final int DEFAULT_COMPRESSION

Default compression level for deflated entries.

See Also:

Constant Field Values

STORED

public static final int STORED

Compression method for stored entries.

See Also:

Constant Field Values

EFS_FLAG

public static final int EFS_FLAG

General purpose flag, which indicates that filenames are written in utf-8.

See Also:

Constant Field Values

def

protected final java.util.zip.Deflater def

This Deflater object is used for output.

Constructor Detail

ZipArchiveOutputStream

public ZipArchiveOutputStream(java.io.OutputStream out)

Creates a new ZIP OutputStream filtering the underlying stream.

Parameters:

out - the outputstream to zip

ZipArchiveOutputStream

public ZipArchiveOutputStream(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

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 putArchiveEntry(ArchiveEntry).

Returns:

true if seekable

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 UTF-8.

Parameters:

encoding - the encoding to use for file names, use null for the platform's default encoding

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.

setUseLanguageEncodingFlag

public void setUseLanguageEncodingFlag(boolean b)

Whether to set the language encoding flag if the file name encoding is UTF-8.

Defaults to true.

setCreateUnicodeExtraFields

public void setCreateUnicodeExtraFields(ZipArchiveOutputStream.UnicodeExtraFieldPolicy b)

Whether to create Unicode Extra Fields.

Defaults to NEVER.

setFallbackToUTF8

public void setFallbackToUTF8(boolean b)

Whether to fall back to UTF and the language encoding flag if the file name cannot be encoded using the specified encoding.

Defaults to false.

finish

public void finish()
            throws java.io.IOException

Description copied from class: ArchiveOutputStream

Finishes the addition of entries to this stream, without closing it. Additional data can be written, if the format supports it. The finish() method throws an Exception if the user forgets to close the entry .

Specified by:

finish in class ArchiveOutputStream

Throws:

java.io.IOException

closeArchiveEntry

public void closeArchiveEntry()
                       throws java.io.IOException

Writes all necessary data for this entry.

Specified by:

closeArchiveEntry in class ArchiveOutputStream

Throws:

java.io.IOException - on error

putArchiveEntry

public void putArchiveEntry(ArchiveEntry archiveEntry)
                     throws java.io.IOException

Writes the headers for an archive entry to the output stream. The caller must then write the content to the stream and call ArchiveOutputStream.closeArchiveEntry() to complete the process.

Specified by:

putArchiveEntry in class ArchiveOutputStream

Parameters:

archiveEntry - describes the entry

Throws:

java.io.IOException

setComment

public void setComment(java.lang.String comment)

Set the file comment.

Parameters:

comment - the comment

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.

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

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.OutputStream

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

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.OutputStream

Throws:

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

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.OutputStream

Throws:

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

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

writeLocalFileHeader

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

Writes the local file header entry

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

writeDataDescriptor

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

Writes the data descriptor entry.

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

writeCentralFileHeader

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

Writes the central file header entry.

Parameters:

ze - the entry to write

Throws:

java.io.IOException - on error

writeCentralDirectoryEnd

protected void writeCentralDirectoryEnd()
                                 throws java.io.IOException

Writes the "End of central dir record".

Throws:

java.io.IOException - on error

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

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

createArchiveEntry

public ArchiveEntry createArchiveEntry(java.io.File inputFile,
                                       java.lang.String entryName)
                                throws java.io.IOException

Description copied from class: ArchiveOutputStream

Create an archive entry using the inputFile and entryName provided.

Specified by:

createArchiveEntry in class ArchiveOutputStream

Returns:

the ArchiveEntry set up with details from the file

Throws:

java.io.IOException