Package java.util.zip

Class GZIPInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.util.zip.InflaterInputStream

java.util.zip.GZIPInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class GZIPInputStream
extends InflaterInputStream

The GZIPInputStream class is used to read data stored in the GZIP format, reading and decompressing GZIP data from the underlying stream into its buffer.

Example

Using GZIPInputStream is easier than ZipInputStream because GZIP is only for compression, and is not a container for multiple files. This code decompresses the data from a GZIP stream, similar to the gunzip(1) utility.

 InputStream is = ...
 GZIPInputStream zis = new GZIPInputStream(new BufferedInputStream(is));
 try {
     // Reading from 'zis' gets you the uncompressed bytes...
     processStream(zis);
 } finally {
     zis.close();
 }
 

Field Summary

Fields

Modifier and Type	Field	Description
protected CRC32	crc	The checksum algorithm used when handling uncompressed data.
protected boolean	eos	Indicates the end of the input stream.
static int	GZIP_MAGIC	The magic header for the GZIP format.

Fields inherited from class java.util.zip.InflaterInputStream

buf, inf, len

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
GZIPInputStream(InputStream is)	Construct a GZIPInputStream to read from GZIP data from the underlying stream.
GZIPInputStream(InputStream is, int size)	Construct a GZIPInputStream to read from GZIP data from the underlying stream.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this stream and any underlying streams.
int	read(byte[] buffer, int byteOffset, int byteCount)	Reads up to byteCount bytes of decompressed data and stores it in buffer starting at byteOffset.

Methods inherited from class java.util.zip.InflaterInputStream

available, fill, mark, markSupported, read, reset, skip

Methods inherited from class java.io.InputStream

read

Methods inherited from class java.lang.Object

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

Field Details

GZIP_MAGIC

public static final int GZIP_MAGIC

The magic header for the GZIP format.

See Also:

Constant Field Values

crc

protected CRC32 crc

The checksum algorithm used when handling uncompressed data.

eos

protected boolean eos

Indicates the end of the input stream.

Constructor Details

GZIPInputStream

public GZIPInputStream(InputStream is) throws IOException

Construct a GZIPInputStream to read from GZIP data from the underlying stream.

Parameters:

is - the InputStream to read data from.

Throws:

IOException - if an IOException occurs.

GZIPInputStream

public GZIPInputStream(InputStream is, int size) throws IOException

Construct a GZIPInputStream to read from GZIP data from the underlying stream. Set the internal buffer size to size.

Parameters:

is - the InputStream to read data from.

size - the internal read buffer size.

Throws:

IOException - if an IOException occurs.

Method Details

close

public void close() throws IOException

Closes this stream and any underlying streams.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InflaterInputStream

Throws:

IOException - If an error occurs closing the input stream.

read

public int read(byte[] buffer, int byteOffset, int byteCount) throws IOException

Description copied from class: InflaterInputStream

Reads up to byteCount bytes of decompressed data and stores it in buffer starting at byteOffset. Returns the number of uncompressed bytes read, or -1.

Overrides:

read in class InflaterInputStream

Throws:

IOException - if the stream is closed or another IOException occurs.