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, java.lang.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.

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.

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
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
static int	STORED Compression method for stored entries.

Constructor Summary

Constructors

Constructor and Description
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.
ZipArchiveOutputStream(java.nio.channels.SeekableByteChannel channel) Creates a new ZIP OutputStream writing to a SeekableByteChannel.

Method Summary

Modifier and Type	Method and Description
void	addRawArchiveEntry(ZipArchiveEntry entry, java.io.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(java.io.File inputFile, java.lang.String entryName) Creates a new zip entry taking some information from the given file and using the provided name.
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	setUseZip64(Zip64Mode mode) Whether Zip64 extensions will be used.
void	write(byte[] b, int offset, int length) Writes bytes to ZIP entry.

Methods inherited from class org.apache.commons.compress.archivers.ArchiveOutputStream

getBytesWritten, getCount, write

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Field Detail

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 filenames are written in UTF-8.

See Also:

Constant Field Values

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

ZipArchiveOutputStream

public ZipArchiveOutputStream(java.nio.channels.SeekableByteChannel channel)
                       throws java.io.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:

java.io.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(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.

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 java.io.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.

java.io.IOException - if the user forgets to close the entry.

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

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,
                               java.io.InputStream rawStream)
                        throws java.io.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:

java.io.IOException - If copying fails

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.lang.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.

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

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

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 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

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.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 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.

createArchiveEntry

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

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