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.

  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 user RandomAccessFile 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
    --- | ---
    `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

    Constructors
    Constructor and Description
    `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

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `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` | `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 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.

    - #### 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`.

      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`.

    - #### 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`

    - #### 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`
      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`
      Returns:
        the ArchiveEntry set up with details from the file
      Throws:
        `IOException`

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