## 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.

As of Apache Ant 1.9.0 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.tools.zip.Zip64Mode)`. If the stream can not user RandomAccessFile and you try to write a ZipEntry of unknown size then Zip64 extensions will be disabled by default.

Nested Class Summary
`static class` `ZipOutputStream.UnicodeExtraFieldPolicy` enum that represents the possible policies for creating Unicode extra fields.

Field Summary
`protected byte[]` `buf` This buffer serves 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.
`static int` `EFS_FLAG` Deprecated. use `GeneralPurposeBit.UFT8_NAMES_FLAG` instead
`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)` Deprecated. use ZipUtil#adjustToLong
`boolean` `canWriteEntryData(ZipEntry 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` `closeEntry()` Writes all necessary data for this entry.
`protected void` `deflate()` Writes next block of compressed data to the output stream.
`void` `finish()`
`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 archiveEntry)`
`void` `setComment(java.lang.String comment)` Set the file comment.
`void` `setCreateUnicodeExtraFields(ZipOutputStream.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.
`protected static ZipLong` `toDosTime(java.util.Date time)` Deprecated. use ZipUtil#toDosTime
`protected static byte[]` `toDosTime(long t)` Deprecated. use ZipUtil#toDosTime
`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(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.
`protected void` `writeZip64CentralDirectory()` Writes the "ZIP64 End of central dir record" and "ZIP64 End of central dir locator".

Methods inherited from class java.io.FilterOutputStream
`write, 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

### 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

### def

    protected final java.util.zip.Deflater def

  This Deflater object is used for output.

### buf

    protected byte[] buf

  This buffer serves 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

### 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(ZipOutputStream.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.

### setUseZip64

    public void setUseZip64(Zip64Mode mode)

  Whether Zip64 extensions will be used.

  When setting the mode to `Never`, `putNextEntry(org.apache.tools.zip.ZipEntry)`, `closeEntry()`, `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 `ZipEntry` is known when calling `putNextEntry(org.apache.tools.zip.ZipEntry)` 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 `putNextEntry(org.apache.tools.zip.ZipEntry)` 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 `putNextEntry(org.apache.tools.zip.ZipEntry)` is called with an entry of unknown size and data is written to a non-seekable stream - in this case the default is `Never`.

  Since:
    1.3

### finish

    public void finish()
                throws java.io.IOException

  Throws:
    `Zip64RequiredException` - if the archive's size exceeds 4 GByte or there are more than 65535 entries inside the archive and `setUseZip64(org.apache.tools.zip.Zip64Mode)` is `Zip64Mode.Never`.
    `java.io.IOException`

### closeEntry

    public void closeEntry()
                    throws java.io.IOException

  Writes all necessary data for this entry.

  Throws:
    `java.io.IOException` - on error
    `Zip64RequiredException` - if the entry's uncompressed or compressed size exceeds 4 GByte and `setUseZip64(org.apache.tools.zip.Zip64Mode)` is `Zip64Mode.Never`.
  Since:
    1.1

### putNextEntry

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

  Throws:
    `Zip64RequiredException` - if the entry's uncompressed or compressed size is known to exceed 4 GByte and `setUseZip64(org.apache.tools.zip.Zip64Mode)` is `Zip64Mode.Never`.
    `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.
  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

### canWriteEntryData

    public boolean canWriteEntryData(ZipEntry 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.

### 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

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

### writeCentralDirectoryEnd

    protected void writeCentralDirectoryEnd()
                                     throws java.io.IOException

  Writes the "End of central dir record".

  Throws:
    `java.io.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`.

### toDosTime

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

  Deprecated. use ZipUtil#toDosTime

  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)

  Deprecated. use ZipUtil#toDosTime

  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

### writeZip64CentralDirectory

    protected void writeZip64CentralDirectory()
                                       throws java.io.IOException

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

  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
  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)

  Deprecated. use ZipUtil#adjustToLong

  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