Package org.apache.mina.filter.compression

Class Zlib

  • class Zlib
extends java.lang.Object
    A helper class for interfacing with the JZlib library. This class acts both as a compressor and decompressor, but only as one at a time. The only flush method supported is Z_SYNC_FLUSH also known as Z_PARTIAL_FLUSH

    • Constructor Summary

      Constructors 
      Constructor Description
      Zlib​(int compressionLevel, int mode)
      Creates an instance of the ZLib class.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void cleanUp()
      Cleans up the resources used by the compression library.
      IoBuffer deflate​(IoBuffer inBuffer)
      Compress the input.
      IoBuffer inflate​(IoBuffer inBuffer)
      Uncompress the given buffer, returning it in a new buffer.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • COMPRESSION_MAX

        public static final int COMPRESSION_MAX
        Try o get the best possible compression
        See Also:
        Constant Field Values

      • COMPRESSION_MIN

        public static final int COMPRESSION_MIN
        Favor speed over compression ratio
        See Also:
        Constant Field Values

      • COMPRESSION_NONE

        public static final int COMPRESSION_NONE
        No compression
        See Also:
        Constant Field Values

      • COMPRESSION_DEFAULT

        public static final int COMPRESSION_DEFAULT
        Default compression
        See Also:
        Constant Field Values

      • compressionLevel

        private int compressionLevel
        The requested compression level

      • zStream

        private com.jcraft.jzlib.ZStream zStream
        The inner stream used to inflate or deflate the data

      • mode

        private int mode
        The selected operation mode : INFLATE or DEFLATE

    • Constructor Detail

      • Zlib

        public Zlib​(int compressionLevel,
            int mode)
        Creates an instance of the ZLib class.
        Parameters:
        compressionLevel - the level of compression that should be used. One of COMPRESSION_MAX, COMPRESSION_MIN, COMPRESSION_NONE or COMPRESSION_DEFAULT
        mode - the mode in which the instance will operate. Can be either of MODE_DEFLATER or MODE_INFLATER
        Throws:
        java.lang.IllegalArgumentException - if the mode is incorrect

    • Method Detail

      • inflate

        public IoBuffer inflate​(IoBuffer inBuffer)
                 throws java.io.IOException
        Uncompress the given buffer, returning it in a new buffer.
        Parameters:
        inBuffer - the IoBuffer to be decompressed. The contents of the buffer are transferred into a local byte array and the buffer is flipped and returned intact.
        Returns:
        the decompressed data
        Throws:
        java.io.IOException - if the decompression of the data failed for some reason.
        java.lang.IllegalArgumentException - if the mode is not MODE_DEFLATER

      • deflate

        public IoBuffer deflate​(IoBuffer inBuffer)
                 throws java.io.IOException
        Compress the input. The result will be put in a new buffer.
        Parameters:
        inBuffer - the buffer to be compressed. The contents are transferred into a local byte array and the buffer is flipped and returned intact.
        Returns:
        the buffer with the compressed data
        Throws:
        java.io.IOException - if the compression of teh buffer failed for some reason
        java.lang.IllegalStateException - if the mode is not MODE_DEFLATER

      • cleanUp

        public void cleanUp()
        Cleans up the resources used by the compression library.