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:

Closeable, 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.

This class is not thread-safe

Nested Class Summary

static class

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

Field Summary

protected 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 Deprecated. use GeneralPurposeBit.UFT8_NAMES_FLAG instead
protected boolean	finished indicates if this archive is finished. protected for use in Jar implementation
static int	STORED Compression method for stored entries.

Constructor Summary

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

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

Method Summary

boolean	canWriteEntryData(ArchiveEntry ae) Whether this stream is able to write the given entry.
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(File inputFile, String entryName) Creates a new zip entry taking some information from the given file and using the provided name.
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.
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(String comment) Set the file comment.
void	setCreateUnicodeExtraFields(ZipArchiveOutputStream.UnicodeExtraFieldPolicy b) Whether to create Unicode Extra Fields.
void	setEncoding(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, count, getBytesWritten, 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

Deprecated. use GeneralPurposeBit.UFT8_NAMES_FLAG instead

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

See Also:

Constant Field Values

def

protected final Deflater def

This Deflater object is used for output.

Constructor Detail

ZipArchiveOutputStream

public ZipArchiveOutputStream(OutputStream out)

Creates a new ZIP OutputStream filtering the underlying stream.

Parameters:

out - the outputstream to zip

ZipArchiveOutputStream

public ZipArchiveOutputStream(File file)
                       throws IOException

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

Parameters:

file - the file to zip to

Throws:

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(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 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 IOException

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:

IOException

closeArchiveEntry

public void closeArchiveEntry()
                       throws IOException

Writes all necessary data for this entry.

Specified by:

closeArchiveEntry in class ArchiveOutputStream

Throws:

IOException - on error

putArchiveEntry

public void putArchiveEntry(ArchiveEntry archiveEntry)
                     throws 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:

ClassCastException - if entry is not an instance of ZipArchiveEntry

IOException

setComment

public void setComment(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:

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

canWriteEntryData

public boolean canWriteEntryData(ArchiveEntry ae)

Whether this stream is able to write the given entry.

May return false if it is set up to use encryption or a compression method that hasn't been implemented yet.

Overrides:

canWriteEntryData in class ArchiveOutputStream

Since:

Apache Commons Compress 1.1

write

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

Writes bytes to ZIP entry.

Overrides:

write in class OutputStream

Parameters:

b - the byte array to write

offset - the start position to write from

length - the number of bytes to write

Throws:

IOException - on error

close

public void close()
           throws IOException

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

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

flush

public void flush()
           throws IOException

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

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException - if an I/O error occurs.

deflate

protected final void deflate()
                      throws IOException

Writes next block of compressed data to the output stream.

Throws:

IOException - on error

writeLocalFileHeader

protected void writeLocalFileHeader(ZipArchiveEntry ze)
                             throws IOException

Writes the local file header entry

Parameters:

ze - the entry to write

Throws:

IOException - on error

writeDataDescriptor

protected void writeDataDescriptor(ZipArchiveEntry ze)
                            throws IOException

Writes the data descriptor entry.

Parameters:

ze - the entry to write

Throws:

IOException - on error

writeCentralFileHeader

protected void writeCentralFileHeader(ZipArchiveEntry ze)
                               throws IOException

Writes the central file header entry.

Parameters:

ze - the entry to write

Throws:

IOException - on error

writeCentralDirectoryEnd

protected void writeCentralDirectoryEnd()
                                 throws IOException

Writes the "End of central dir record".

Throws:

IOException - on error

writeOut

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

Write bytes to output or random access file.

Parameters:

data - the byte array to write

Throws:

IOException - on error

writeOut

protected final void writeOut(byte[] data,
                              int offset,
                              int length)
                       throws 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:

IOException - on error

createArchiveEntry

public ArchiveEntry createArchiveEntry(File inputFile,
                                       String entryName)
                                throws IOException

Creates a new zip entry taking some information from the given file and using the provided name.

The name will be adjusted to end with a forward slash "/" if the file is a directory. If the file is not a directory a potential trailing forward slash will be stripped from the entry name.

Must not be used if the stream has already been closed.

Specified by:

createArchiveEntry in class ArchiveOutputStream

Returns:

the ArchiveEntry set up with details from the file

Throws:

IOException