Interface Pack200.Unpacker

All Known Implementing Classes:
UnpackerImpl
Enclosing class:
Pack200
public static interface Pack200.Unpacker
The unpacker engine converts the packed stream to a JAR file. An instance of the engine can be obtained using Pack200.newUnpacker().

Every JAR file produced by this engine will include the string "PACK200" as a zip file comment. This allows a deployer to detect if a JAR archive was packed and unpacked.

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

This version of the unpacker is compatible with all previous versions.

Since:
1.5
Author:
John Rose, Kumar Srinivasan

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    DEFLATE_HINT
    Property indicating that the unpacker should ignore all transmitted values for DEFLATE_HINT, replacing them by the given value, TRUE or FALSE.
    static final String
    FALSE
    The string "false", a possible value for certain properties.
    static final String
    KEEP
    The string "keep", a possible value for certain properties.
    static final String
    PROGRESS
    The unpacker's progress as a percentage, as periodically updated by the unpacker.
    static final String
    TRUE
    The string "true", a possible value for certain properties.

  • Method Summary

    Modifier and Type
    Method
    Description
    SortedMap<String,String>
    properties()
    Get the set of this engine's properties.
    void
    unpack(File in, JarOutputStream out)
    Read a Pack200 archive, and write the encoded JAR to a JarOutputStream.
    void
    unpack(InputStream in, JarOutputStream out)
    Read a Pack200 archive, and write the encoded JAR to a JarOutputStream.

  • Field Details

    • KEEP

      static final String KEEP
      The string "keep", a possible value for certain properties.
      See Also:

    • TRUE

      static final String TRUE
      The string "true", a possible value for certain properties.
      See Also:

    • FALSE

      static final String FALSE
      The string "false", a possible value for certain properties.
      See Also:

    • DEFLATE_HINT

      static final String DEFLATE_HINT
      Property indicating that the unpacker should ignore all transmitted values for DEFLATE_HINT, replacing them by the given value, TRUE or FALSE. The default value is the special string KEEP, which asks the unpacker to preserve all transmitted deflation hints.
      See Also:

    • PROGRESS

      static final String PROGRESS
      The unpacker's progress as a percentage, as periodically updated by the unpacker. Values of 0 - 100 are normal, and -1 indicates a stall. Progress can be monitored by polling the value of this property.

      At a minimum, the unpacker must set progress to 0 at the beginning of an unpacking operation, and to 100 at the end.

      See Also:

  • Method Details

    • properties

      SortedMap<String,String> properties()
      Get the set of this engine's properties. This set is a "live view", so that changing its contents immediately affects the Unpacker engine, and changes from the engine (such as progress indications) are immediately visible in the map.

      The property map may contain pre-defined implementation specific and default properties. Users are encouraged to read the information and fully understand the implications, before modifying pre-existing properties.

      Implementation specific properties are prefixed with a package name associated with the implementor, beginning with com. or a similar prefix. All property names beginning with pack. and unpack. are reserved for use by this API.

      Unknown properties may be ignored or rejected with an unspecified error, and invalid entries may cause an unspecified error to be thrown.

      Returns:
      A sorted association of option key strings to option values.

    • unpack

      void unpack(InputStream in, JarOutputStream out) throws IOException
      Read a Pack200 archive, and write the encoded JAR to a JarOutputStream. The entire contents of the input stream will be read. It may be more efficient to read the Pack200 archive to a file and pass the File object, using the alternate method described below.

      Closes its input but not its output. (The output can accumulate more elements.)

      Parameters:
      in - an InputStream.
      out - a JarOutputStream.
      Throws:
      IOException - if an error is encountered.

    • unpack

      void unpack(File in, JarOutputStream out) throws IOException
      Read a Pack200 archive, and write the encoded JAR to a JarOutputStream.

      Does not close its output. (The output can accumulate more elements.)

      Parameters:
      in - a File.
      out - a JarOutputStream.
      Throws:
      IOException - if an error is encountered.