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, AutoCloseable

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 SeekableByteChannel when it knows that the output is going to go to a file and no split archive shall be created.

If SeekableByteChannel 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.

As of Apache Commons Compress 1.3 it transparently supports Zip64 extensions and thus individual entries and archives larger than 4 GB or with more than 65536 entries in most cases but explicit control is provided via setUseZip64(org.apache.commons.compress.archivers.zip.Zip64Mode). If the stream can not use SeekableByteChannel and you try to write a ZipArchiveEntry of unknown size then Zip64 extensions will be disabled by default.

This class is not thread-safe

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ZipArchiveOutputStream.UnicodeExtraFieldPolicy enum that represents the possible policies for creating Unicode extra fields.

Field Summary

Fields

Modifier and Type	Field and Description
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.
static int	STORED Compression method for stored entries.

Constructor Summary

Constructors

Constructor and Description
ZipArchiveOutputStream(File file) Creates a new ZIP OutputStream writing to a File.
ZipArchiveOutputStream(File file, long zipSplitSize) Creates a split ZIP Archive.
ZipArchiveOutputStream(OutputStream out) Creates a new ZIP OutputStream filtering the underlying stream.
ZipArchiveOutputStream(SeekableByteChannel channel) Creates a new ZIP OutputStream writing to a SeekableByteChannel.

Method Summary

Modifier and Type	Method and Description
void	addRawArchiveEntry(ZipArchiveEntry entry, InputStream rawStream) Adds an archive entry with a raw input stream.
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 file names 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 file names 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	setUseZip64(Zip64Mode mode) Whether Zip64 extensions will be used.
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.
protected void	writeZip64CentralDirectory() Writes the "ZIP64 End of central dir record" and "ZIP64 End of central dir locator".

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

@Deprecated
public static final int EFS_FLAG

Deprecated. use GeneralPurposeBit.UFT8_NAMES_FLAG instead

General purpose flag, which indicates that file names 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

ZipArchiveOutputStream

public ZipArchiveOutputStream(File file,
                              long zipSplitSize)
                       throws IOException

Creates a split ZIP Archive.

The files making up the archive will use Z01, Z02, ... extensions and the last part of it will be the given file.

Even though the stream writes to a file this stream will behave as if no random access was possible. This means the sizes of stored entries need to be known before the actual entry data is written.

Parameters:

file - the file that will become the last part of the split archive

zipSplitSize - maximum size of a single part of the split archive created by this stream. Must be between 64kB and about 4GB.

Throws:

IOException - on error

IllegalArgumentException - if zipSplitSize is not in the required range

Since:

1.20

ZipArchiveOutputStream

public ZipArchiveOutputStream(SeekableByteChannel channel)
                       throws IOException

Creates a new ZIP OutputStream writing to a SeekableByteChannel.

SeekableInMemoryByteChannel allows you to write to an in-memory archive using random access.

Parameters:

channel - the channel to zip to

Throws:

IOException - on error

Since:

1.13

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 file names 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 file names 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.

Parameters:

b - whether to set the language encoding flag if the file name encoding is UTF-8

setCreateUnicodeExtraFields

public void setCreateUnicodeExtraFields(ZipArchiveOutputStream.UnicodeExtraFieldPolicy b)

Whether to create Unicode Extra Fields.

Defaults to NEVER.

Parameters:

b - whether to create Unicode Extra Fields.

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.

Parameters:

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

setUseZip64

public void setUseZip64(Zip64Mode mode)

Whether Zip64 extensions will be used.

When setting the mode to Never, putArchiveEntry(org.apache.commons.compress.archivers.ArchiveEntry), closeArchiveEntry(), finish() or close() may throw a Zip64RequiredException if the entry's size or the total size of the archive exceeds 4GB or there are more than 65536 entries inside the archive. Any archive created in this mode will be readable by implementations that don't support Zip64.

When setting the mode to Always, Zip64 extensions will be used for all entries. Any archive created in this mode may be unreadable by implementations that don't support Zip64 even if all its contents would be.

When setting the mode to AsNeeded, Zip64 extensions will transparently be used for those entries that require them. This mode can only be used if the uncompressed size of the ZipArchiveEntry is known when calling putArchiveEntry(org.apache.commons.compress.archivers.ArchiveEntry) or the archive is written to a seekable output (i.e. you have used the File-arg constructor) - this mode is not valid when the output stream is not seekable and the uncompressed size is unknown when putArchiveEntry(org.apache.commons.compress.archivers.ArchiveEntry) is called.

If no entry inside the resulting archive requires Zip64 extensions then Never will create the smallest archive. AsNeeded will create a slightly bigger archive if the uncompressed size of any entry has initially been unknown and create an archive identical to Never otherwise. Always will create an archive that is at least 24 bytes per entry bigger than the one Never would create.

Defaults to AsNeeded unless putArchiveEntry(org.apache.commons.compress.archivers.ArchiveEntry) is called with an entry of unknown size and data is written to a non-seekable stream - in this case the default is Never.

Parameters:

mode - Whether Zip64 extensions will be used.

Since:

1.3

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.

Specified by:

finish in class ArchiveOutputStream

Throws:

Zip64RequiredException - if the archive's size exceeds 4 GByte or there are more than 65535 entries inside the archive and setUseZip64(org.apache.commons.compress.archivers.zip.Zip64Mode) is Zip64Mode.Never.

IOException - if the user forgets to close the entry.

closeArchiveEntry

public void closeArchiveEntry()
                       throws IOException

Writes all necessary data for this entry.

Specified by:

closeArchiveEntry in class ArchiveOutputStream

Throws:

IOException - on error

Zip64RequiredException - if the entry's uncompressed or compressed size exceeds 4 GByte and setUseZip64(org.apache.commons.compress.archivers.zip.Zip64Mode) is Zip64Mode.Never.

addRawArchiveEntry

public void addRawArchiveEntry(ZipArchiveEntry entry,
                               InputStream rawStream)
                        throws IOException

Adds an archive entry with a raw input stream. If crc, size and compressed size are supplied on the entry, these values will be used as-is. Zip64 status is re-established based on the settings in this stream, and the supplied value is ignored. The entry is put and closed immediately.

Parameters:

entry - The archive entry to add

rawStream - The raw input stream of a different entry. May be compressed/encrypted.

Throws:

IOException - If copying fails

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

Zip64RequiredException - if the entry's uncompressed or compressed size is known to exceed 4 GByte and setUseZip64(org.apache.commons.compress.archivers.zip.Zip64Mode) is Zip64Mode.Never.

IOException - if an I/O error occurs

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

Parameters:

ae - the entry to test

Returns:

This implementation always returns true.

Since:

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

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

Zip64RequiredException - if the archive's size exceeds 4 GByte or there are more than 65535 entries inside the archive and setUseZip64(org.apache.commons.compress.archivers.zip.Zip64Mode) is Zip64Mode.Never.

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

Zip64RequiredException - if the archive's size exceeds 4 GByte and #setUseZip64 is Zip64Mode.Never.

writeCentralDirectoryEnd

protected void writeCentralDirectoryEnd()
                                 throws IOException

Writes the "End of central dir record".

Throws:

IOException - on error

Zip64RequiredException - if the archive's size exceeds 4 GByte or there are more than 65535 entries inside the archive and #setUseZip64 is Zip64Mode.Never.

writeZip64CentralDirectory

protected void writeZip64CentralDirectory()
                                   throws IOException

Writes the "ZIP64 End of central dir record" and "ZIP64 End of central dir locator".

Throws:

IOException - on error

Since:

1.3

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

Parameters:

inputFile - the file to create the entry from

entryName - name to use for the entry

Returns:

the ArchiveEntry set up with details from the file

Throws:

IOException - if an I/O error occurs