de.enough.polish.util.zip
Class GZipInputStream

java.lang.Object
  java.io.InputStream
      de.enough.polish.util.zip.GZipInputStream

All Implemented Interfaces:

Closeable

public class GZipInputStream
extends InputStream

Reads and uncompresses GZIP or DEFLATE encoded input streams.

Copyright Enough Software 2007 - 2010

 history
        Jun 25, 2007 - Simon creation
 

Author:

Simon Schmitt, simon.schmitt@enough.de

Field Summary

static int	TYPE_DEFLATE This constant triggers the normal deflate compression as described in rfc 1951.
static int	TYPE_GZIP This constant triggers the gzip compression that is the same as deflate with some extra header information (see rfc 1952).

Constructor Summary

GZipInputStream(InputStream inputStream, int compressionType, boolean hash)
Creates an input stream capable of GZIP and Deflate with a buffer of 1024 bytes.

GZipInputStream(InputStream inputStream, int size, int compressionType, boolean hash)
Creates an input stream capable of GZIP and Deflate.

Method Summary

int	available() This function fills the buffer and returns the amount of avialable data.
void	close()
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
long	skip(long n)
int	validData() Checks if the current status is valid

Methods inherited from class java.io.InputStream

mark, markSupported, reset

Methods inherited from class java.lang.Object

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

Field Detail

TYPE_DEFLATE

public static final int TYPE_DEFLATE

This constant triggers the normal deflate compression as described in rfc 1951.

See Also:

Constant Field Values

TYPE_GZIP

public static final int TYPE_GZIP

This constant triggers the gzip compression that is the same as deflate with some extra header information (see rfc 1952).

See Also:

Constant Field Values

Constructor Detail

GZipInputStream

public GZipInputStream(InputStream inputStream,
                       int compressionType,
                       boolean hash)
                throws IOException

Creates an input stream capable of GZIP and Deflate with a buffer of 1024 bytes.

Parameters:

inputStream - the stream that contains the compressed data.

compressionType - TYPE_GZIP or TYPE_DEFLATE

hash - set true for data checking, set false for speed reading

Throws:

IOException - when the header of a GZIP stream cannot be skipped

See Also:

TYPE_DEFLATE, TYPE_GZIP

GZipInputStream

public GZipInputStream(InputStream inputStream,
                       int size,
                       int compressionType,
                       boolean hash)
                throws IOException

Creates an input stream capable of GZIP and Deflate.

Parameters:

inputStream - the stream that contains the compressed data.

size - the size of the internally used buffer

compressionType - TYPE_GZIP or TYPE_DEFLATE

hash - set true for data checking, set false for speed reading

Throws:

IOException - when the header of a GZIP stream cannot be skipped

See Also:

TYPE_DEFLATE, TYPE_GZIP

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

validData

public int validData()
              throws IOException

Checks if the current status is valid

Returns:

-1 if the stream is finished, 1 if the current data is valid, 0 if not

Throws:

IOException

available

public int available()
              throws IOException

This function fills the buffer and returns the amount of avialable data. Therefore it will always return the buffer size that was given to the constructor.

Overrides:

available in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException