Class ZipOutputStream

All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
Direct Known Subclasses:
JarOutputStream

public class ZipOutputStream extends DeflaterOutputStream
This class implements an output stream filter for writing files in the ZIP file format. Includes support for both compressed and uncompressed entries.

Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a NullPointerException to be thrown.

Since:
1.1
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    Central directory (CEN) header internal file attributes field offset.
    static final int
    Central directory (CEN) header external file attributes field offset.
    static final int
    Central directory (CEN) header comment length field offset.
    static final int
    Central directory (CEN) header uncompressed file crc-32 value field offset.
    static final int
    Central directory (CEN) header disk number start field offset.
    static final int
    Central directory (CEN) header extra field length field offset.
    static final int
    Central directory (CEN) header encrypt, decrypt flags field offset.
    static final int
    Central directory (CEN) header size in bytes (including signature).
    static final int
    Central directory (CEN) header compression method field offset.
    static final int
    Central directory (CEN) header uncompressed size field offset.
    static final int
    Central directory (CEN) header filename length field offset.
    static final int
    Central directory (CEN) header LOC header offset field offset.
    static final long
    Central directory (CEN) header signature.
    static final int
    Central directory (CEN) header compressed size field offset.
    static final int
    Central directory (CEN) header modification time field offset.
    static final int
    Central directory (CEN) header version made by field offset.
    static final int
    Central directory (CEN) header version needed to extract field offset.
    static final int
    Compression method for compressed (DEFLATED) entries.
    static final int
    End of central directory (END) header ZIP file comment length field offset.
    static final int
    End of central directory (END) header size in bytes (including signature).
    static final int
    End of central directory (END) header offset for the first CEN header field offset.
    static final long
    End of central directory (END) header signature.
    static final int
    End of central directory (END) header central directory size in bytes field offset.
    static final int
    End of central directory (END) header number of entries on this disk field offset.
    static final int
    End of central directory (END) header total number of entries field offset.
    static final int
    Extra local (EXT) header uncompressed file crc-32 value field offset.
    static final int
    Extra local (EXT) header size in bytes (including signature).
    static final int
    Extra local (EXT) header uncompressed size field offset.
    static final long
    Extra local (EXT) header signature.
    static final int
    Extra local (EXT) header compressed size field offset.
    static final int
    Local file (LOC) header uncompressed file crc-32 value field offset.
    static final int
    Local file (LOC) header extra field length field offset.
    static final int
    Local file (LOC) header general purpose bit flag field offset.
    static final int
    Local file (LOC) header size in bytes (including signature).
    static final int
    Local file (LOC) header compression method field offset.
    static final int
    Local file (LOC) header uncompressed size field offset.
    static final int
    Local file (LOC) header filename length field offset.
    static final long
    Local file (LOC) header signature.
    static final int
    Local file (LOC) header compressed size field offset.
    static final int
    Local file (LOC) header modification time field offset.
    static final int
    Local file (LOC) header version needed to extract field offset.
    static final int
    Compression method for uncompressed (STORED) entries.

    Fields inherited from class java.util.zip.DeflaterOutputStream

    buf, def

    Fields inherited from class java.io.FilterOutputStream

    out
  • Constructor Summary

    Constructors
    Constructor
    Description
    Creates a new ZIP output stream.
    Creates a new ZIP output stream.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Closes the underlying stream and the stream being filtered after the contents of the ZIP output stream are fully written.
    void
    Closes the current ZIP entry and positions the stream for writing the next entry.
    void
    Finishes writing the contents of the ZIP output stream without closing the underlying stream.
    void
    Begins writing a new ZIP file entry and positions the stream to the start of the entry data.
    void
    setComment(String comment)
    Sets the ZIP file comment.
    void
    setLevel(int level)
    Sets the compression level for subsequent entries which are DEFLATED.
    void
    setMethod(int method)
    Sets the default compression method for subsequent entries.
    void
    write(byte[] b, int off, int len)
    Writes an array of bytes to the current ZIP entry data.

    Methods inherited from class java.util.zip.DeflaterOutputStream

    deflate, flush, write

    Methods inherited from class java.io.FilterOutputStream

    write

    Methods inherited from class java.io.OutputStream

    nullOutputStream

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • STORED

      public static final int STORED
      Compression method for uncompressed (STORED) entries.
      See Also:
    • DEFLATED

      public static final int DEFLATED
      Compression method for compressed (DEFLATED) entries.
      See Also:
    • LOCSIG

      static final long LOCSIG
      Local file (LOC) header signature.
      See Also:
    • EXTSIG

      static final long EXTSIG
      Extra local (EXT) header signature.
      See Also:
    • CENSIG

      static final long CENSIG
      Central directory (CEN) header signature.
      See Also:
    • ENDSIG

      static final long ENDSIG
      End of central directory (END) header signature.
      See Also:
    • LOCHDR

      static final int LOCHDR
      Local file (LOC) header size in bytes (including signature).
      See Also:
    • EXTHDR

      static final int EXTHDR
      Extra local (EXT) header size in bytes (including signature).
      See Also:
    • CENHDR

      static final int CENHDR
      Central directory (CEN) header size in bytes (including signature).
      See Also:
    • ENDHDR

      static final int ENDHDR
      End of central directory (END) header size in bytes (including signature).
      See Also:
    • LOCVER

      static final int LOCVER
      Local file (LOC) header version needed to extract field offset.
      See Also:
    • LOCFLG

      static final int LOCFLG
      Local file (LOC) header general purpose bit flag field offset.
      See Also:
    • LOCHOW

      static final int LOCHOW
      Local file (LOC) header compression method field offset.
      See Also:
    • LOCTIM

      static final int LOCTIM
      Local file (LOC) header modification time field offset.
      See Also:
    • LOCCRC

      static final int LOCCRC
      Local file (LOC) header uncompressed file crc-32 value field offset.
      See Also:
    • LOCSIZ

      static final int LOCSIZ
      Local file (LOC) header compressed size field offset.
      See Also:
    • LOCLEN

      static final int LOCLEN
      Local file (LOC) header uncompressed size field offset.
      See Also:
    • LOCNAM

      static final int LOCNAM
      Local file (LOC) header filename length field offset.
      See Also:
    • LOCEXT

      static final int LOCEXT
      Local file (LOC) header extra field length field offset.
      See Also:
    • EXTCRC

      static final int EXTCRC
      Extra local (EXT) header uncompressed file crc-32 value field offset.
      See Also:
    • EXTSIZ

      static final int EXTSIZ
      Extra local (EXT) header compressed size field offset.
      See Also:
    • EXTLEN

      static final int EXTLEN
      Extra local (EXT) header uncompressed size field offset.
      See Also:
    • CENVEM

      static final int CENVEM
      Central directory (CEN) header version made by field offset.
      See Also:
    • CENVER

      static final int CENVER
      Central directory (CEN) header version needed to extract field offset.
      See Also:
    • CENFLG

      static final int CENFLG
      Central directory (CEN) header encrypt, decrypt flags field offset.
      See Also:
    • CENHOW

      static final int CENHOW
      Central directory (CEN) header compression method field offset.
      See Also:
    • CENTIM

      static final int CENTIM
      Central directory (CEN) header modification time field offset.
      See Also:
    • CENCRC

      static final int CENCRC
      Central directory (CEN) header uncompressed file crc-32 value field offset.
      See Also:
    • CENSIZ

      static final int CENSIZ
      Central directory (CEN) header compressed size field offset.
      See Also:
    • CENLEN

      static final int CENLEN
      Central directory (CEN) header uncompressed size field offset.
      See Also:
    • CENNAM

      static final int CENNAM
      Central directory (CEN) header filename length field offset.
      See Also:
    • CENEXT

      static final int CENEXT
      Central directory (CEN) header extra field length field offset.
      See Also:
    • CENCOM

      static final int CENCOM
      Central directory (CEN) header comment length field offset.
      See Also:
    • CENDSK

      static final int CENDSK
      Central directory (CEN) header disk number start field offset.
      See Also:
    • CENATT

      static final int CENATT
      Central directory (CEN) header internal file attributes field offset.
      See Also:
    • CENATX

      static final int CENATX
      Central directory (CEN) header external file attributes field offset.
      See Also:
    • CENOFF

      static final int CENOFF
      Central directory (CEN) header LOC header offset field offset.
      See Also:
    • ENDSUB

      static final int ENDSUB
      End of central directory (END) header number of entries on this disk field offset.
      See Also:
    • ENDTOT

      static final int ENDTOT
      End of central directory (END) header total number of entries field offset.
      See Also:
    • ENDSIZ

      static final int ENDSIZ
      End of central directory (END) header central directory size in bytes field offset.
      See Also:
    • ENDOFF

      static final int ENDOFF
      End of central directory (END) header offset for the first CEN header field offset.
      See Also:
    • ENDCOM

      static final int ENDCOM
      End of central directory (END) header ZIP file comment length field offset.
      See Also:
  • Constructor Details

    • ZipOutputStream

      public ZipOutputStream(OutputStream out)
      Creates a new ZIP output stream.

      The UTF-8 charset is used to encode the entry names and comments.

      Parameters:
      out - the actual output stream
    • ZipOutputStream

      public ZipOutputStream(OutputStream out, Charset charset)
      Creates a new ZIP output stream.
      Parameters:
      out - the actual output stream
      charset - the charset to be used to encode the entry names and comments
      Since:
      1.7
  • Method Details

    • setComment

      public void setComment(String comment)
      Sets the ZIP file comment.
      Parameters:
      comment - the comment string
      Throws:
      IllegalArgumentException - if the length of the specified ZIP file comment is greater than 0xFFFF bytes
    • setMethod

      public void setMethod(int method)
      Sets the default compression method for subsequent entries. This default will be used whenever the compression method is not specified for an individual ZIP file entry, and is initially set to DEFLATED.
      Parameters:
      method - the default compression method
      Throws:
      IllegalArgumentException - if the specified compression method is invalid
    • setLevel

      public void setLevel(int level)
      Sets the compression level for subsequent entries which are DEFLATED. The default setting is DEFAULT_COMPRESSION.
      Parameters:
      level - the compression level (0-9)
      Throws:
      IllegalArgumentException - if the compression level is invalid
    • putNextEntry

      public void putNextEntry(ZipEntry e) throws IOException
      Begins writing a new ZIP file entry and positions the stream to the start of the entry data. Closes the current entry if still active.

      The default compression method will be used if no compression method was specified for the entry. When writing a compressed (DEFLATED) entry, and the compressed size has not been explicitly set with the ZipEntry.setCompressedSize(long) method, then the compressed size will be set to the actual compressed size after deflation.

      The current time will be used if the entry has no set modification time.

      API Note:
      When writing a directory entry, the STORED compression method should be used and the size and CRC-32 values should be set to 0:
           ZipEntry e = new ZipEntry(entryName);
           if (e.isDirectory()) {
               e.setMethod(ZipEntry.STORED);
               e.setSize(0);
               e.setCrc(0);
           }
           stream.putNextEntry(e);
      
      This allows optimal performance when processing directory entries.
      Parameters:
      e - the ZIP entry to be written
      Throws:
      ZipException - if a ZIP format error has occurred
      IOException - if an I/O error has occurred
    • closeEntry

      public void closeEntry() throws IOException
      Closes the current ZIP entry and positions the stream for writing the next entry.
      Throws:
      ZipException - if a ZIP format error has occurred
      IOException - if an I/O error has occurred
    • write

      public void write(byte[] b, int off, int len) throws IOException
      Writes an array of bytes to the current ZIP entry data. This method will block until all the bytes are written.
      Overrides:
      write in class DeflaterOutputStream
      Parameters:
      b - the data to be written
      off - the start offset in the data
      len - the number of bytes that are written
      Throws:
      ZipException - if a ZIP file error has occurred
      IOException - if an I/O error has occurred
      See Also:
    • finish

      public void finish() throws IOException
      Finishes writing the contents of the ZIP output stream without closing the underlying stream. Use this method when applying multiple filters in succession to the same output stream.

      A ZipException will be thrown if the combined length, after encoding, of the entry name, the extra field data, the entry comment and CEN Header size, exceeds 65,535 bytes.

      Overrides:
      finish in class DeflaterOutputStream
      Throws:
      ZipException - if a ZIP file error has occurred
      IOException - if an I/O exception has occurred
    • close

      public void close() throws IOException
      Closes the underlying stream and the stream being filtered after the contents of the ZIP output stream are fully written.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class DeflaterOutputStream
      Throws:
      ZipException - if a ZIP file error has occurred
      IOException - if an I/O error has occurred
      See Also: