java.util.zip
Class GZIPInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          java.util.zip.InflaterInputStream
              java.util.zip.GZIPInputStream

public class GZIPInputStream

extends InflaterInputStream

This class implements a stream filter for reading compressed data in the GZIP format.

Author:

David Connelly

See Also:

InflaterInputStream

Field Summary

private boolean	closed
protected CRC32	crc CRC-32 for uncompressed data.
protected boolean	eos Indicates end of input stream.
private static int	FCOMMENT
private static int	FEXTRA
private static int	FHCRC
private static int	FNAME
private static int	FTEXT
static int	GZIP_MAGIC GZIP header magic number.
private byte[]	tmpbuf

Fields inherited from class java.util.zip.InflaterInputStream

buf, inf, len, usesDefaultInflater

Fields inherited from class java.io.FilterInputStream

in

Fields inherited from class java.io.InputStream

Constructor Summary

GZIPInputStream(InputStream in)
Creates a new input stream with a default buffer size.

GZIPInputStream(InputStream in, int size)
Creates a new input stream with the specified buffer size.

Method Summary

void	close() Closes the input stream.
private void	ensureOpen() Check to make sure that this stream has not been closed
int	read(byte[] buf, int off, int len) Reads uncompressed data into an array of bytes.
private void	readHeader()
private void	readTrailer()
private int	readUByte(InputStream in)
private long	readUInt(InputStream in)
private int	readUShort(InputStream in)
private void	skipBytes(InputStream in, int n)

Methods inherited from class java.util.zip.InflaterInputStream

available, fill, read, skip

Methods inherited from class java.io.FilterInputStream

mark, markSupported, read, reset

Methods inherited from class java.lang.Object

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

Field Detail

crc

protected CRC32 crc

CRC-32 for uncompressed data.

eos

protected boolean eos

Indicates end of input stream.

closed

private boolean closed

GZIP_MAGIC

public static final int GZIP_MAGIC

GZIP header magic number.

See Also:

Constant Field Values

FTEXT

private static final int FTEXT

See Also:

Constant Field Values

FHCRC

private static final int FHCRC

See Also:

Constant Field Values

FEXTRA

private static final int FEXTRA

See Also:

Constant Field Values

FNAME

private static final int FNAME

See Also:

Constant Field Values

FCOMMENT

private static final int FCOMMENT

See Also:

Constant Field Values

tmpbuf

private byte[] tmpbuf

Constructor Detail

GZIPInputStream

public GZIPInputStream(InputStream in,
                       int size)
                throws IOException

Creates a new input stream with the specified buffer size.

Parameters:

in - the input stream

size - the input buffer size

Throws:

IOException - if an I/O error has occurred

IllegalArgumentException - if size is <= 0

GZIPInputStream

public GZIPInputStream(InputStream in)
                throws IOException

Creates a new input stream with a default buffer size.

Parameters:

in - the input stream

Throws:

IOException - if an I/O error has occurred

Method Detail

ensureOpen

private void ensureOpen()
                 throws IOException

Check to make sure that this stream has not been closed

Throws:

IOException

read

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

Reads uncompressed data into an array of bytes. Blocks until enough input is available for decompression.

Overrides:

read in class InflaterInputStream

Parameters:

buf - the buffer into which the data is read

off - the start offset of the data

len - the maximum number of bytes read

Returns:

the actual number of bytes read, or -1 if the end of the compressed input stream is reached

Throws:

IOException - if an I/O error has occurred or the compressed input data is corrupt

close

public void close()
           throws IOException

Closes the input stream.

Overrides:

close in class InflaterInputStream

Throws:

IOException - if an I/O error has occurred

readHeader

private void readHeader()
                 throws IOException

Throws:

IOException

readTrailer

private void readTrailer()
                  throws IOException

Throws:

IOException

readUInt

private long readUInt(InputStream in)
               throws IOException

Throws:

IOException

readUShort

private int readUShort(InputStream in)
                throws IOException

Throws:

IOException

readUByte

private int readUByte(InputStream in)
               throws IOException

Throws:

IOException

skipBytes

private void skipBytes(InputStream in,
                       int n)
                throws IOException

Throws:

IOException