iaik.cms

Class ZLIBCompressionInputStream

java.lang.Object

iaik.cms.ZLIBCompressionInputStream

All Implemented Interfaces:

InputStreamCompressEngine

public class ZLIBCompressionInputStream
extends java.lang.Object
implements InputStreamCompressEngine

The ZLIBCompressionInputStream is used to wrap a standard InputStream so that ZLIB compression can be applied to the stream. It uses the ZLIB implementation from Sun's java.util.zip package. The ZLIBCompressionInputStream implements the InputStreamCompressEngine interface which is used by the CompressionProvider.getInputStreamCompressEngine() method. Therefore, implementors can choose to compress the supplied data with any type of compression algorithm by the following means:

 1.  Extend the CompressionProvider class, and override method getInputStreamCompressEngine,
 which is specified as follows:
 
  if(algorithmid.equals(CompressionProvider.zlib_compress))
      return new ZLIBCompressionInputStream(inputstream, CompressMode, blocksize);
  else
     throw new NoSuchAlgorithmException("Algorithm " + algorithmid.getAlgorithm().getName() + " not available!");
 
 2.  Specify the AlgorithmID for the compression algorithm being used.  This AlgorithmID
 should be added into the extension of the CompressionProvider as CompressionProvider is
 an extension of AlgorithmID. 
 
 3.  Write a Compression InputStream class which implements interface
 InputStreamCompressEngine and make sure the getInputStream() method is 
 implemented.
 

Field Summary

Fields inherited from interface iaik.cms.InputStreamCompressEngine

COMPRESS, DECOMPRESS

Constructor Summary

Constructors

Constructor and Description
ZLIBCompressionInputStream(java.io.InputStream inputstream, int CompressMode, int blocksize) Wrap the given inputstream with the ZLIBCompressionInputStream given the CompressMode (InputStreamCompressEngine.COMPRESS) or (InputStreamCompressEngine.DECOMPRESS) as well as the blocksize.

Method Summary

Modifier and Type	Method and Description
java.io.InputStream	getInputStream() This method returns the ZLIBCompressionInputStream

Methods inherited from class java.lang.Object

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

Constructor Detail

ZLIBCompressionInputStream

public ZLIBCompressionInputStream(java.io.InputStream inputstream,
                                  int CompressMode,
                                  int blocksize)

Wrap the given inputstream with the ZLIBCompressionInputStream given the CompressMode (InputStreamCompressEngine.COMPRESS) or (InputStreamCompressEngine.DECOMPRESS) as well as the blocksize. If blocksize <= 0 then the entire contents of the stream will be processed in memory.

Parameters:

inputstream - the inputstream to be wrapped

CompressMode - the compression mode, one of InputStreamCompressEngine.COMPRESS or InputStreamCompressEngine.DECOMPRESS

blocksize - the blocksize used for processing the inputstream.

Method Detail

getInputStream

public java.io.InputStream getInputStream()

This method returns the ZLIBCompressionInputStream

Specified by:

getInputStream in interface InputStreamCompressEngine

Returns:

the ZLIBCompressionInputStream