Module java.base

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

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

Since:

1.1

See Also:

• InflaterInputStream

Field Summary

Fields

Modifier and Type	Field	Description
protected CRC32	crc	CRC-32 for uncompressed data.
protected boolean	eos	Indicates end of input stream.
static final int	GZIP_MAGIC	GZIP header magic number.

Fields declared in class java.util.zip.InflaterInputStream

buf, inf, len

Fields declared in class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
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

Modifier and Type	Method	Description
void	close()	Closes this input stream and releases any system resources associated with the stream.
int	read(byte[] buf, int off, int len)	Reads uncompressed data into an array of bytes, returning the number of inflated bytes.

Methods declared in class java.util.zip.InflaterInputStream

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

Methods declared in class java.io.FilterInputStream

read

Methods declared in class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods declared in class java.lang.Object

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

Field Details

crc

protected CRC32 crc

CRC-32 for uncompressed data.

eos

protected boolean eos

Indicates end of input stream.

GZIP_MAGIC

public static final int GZIP_MAGIC

GZIP header magic number.

See Also:

• Constant Field Values

Constructor Details

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:

ZipException - if a GZIP format error has occurred or the compression method used is unsupported

IOException - if an I/O error has occurred

IllegalArgumentException - if size <= 0

GZIPInputStream

public GZIPInputStream(InputStream in)
                throws IOException

Creates a new input stream with a default buffer size.

Parameters:

in - the input stream

Throws:

ZipException - if a GZIP format error has occurred or the compression method used is unsupported

IOException - if an I/O error has occurred

Method Details

read

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

Reads uncompressed data into an array of bytes, returning the number of inflated bytes. If len is not zero, the method will block until some input can be decompressed; otherwise, no bytes are read and 0 is returned.

If this method returns a nonzero integer n then buf[off] through buf[off+n-1] contain the uncompressed data. The content of elements buf[off+n] through buf[off+len-1] is undefined, contrary to the specification of the InputStream superclass, so an implementation is free to modify these elements during the inflate operation. If this method returns -1 or throws an exception then the content of buf[off] through buf[off+len -1] is undefined.

Overrides:

read in class InflaterInputStream

Parameters:

buf - the buffer into which the data is read

off - the start offset in the destination array buf

len - the maximum number of bytes read

Returns:

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

Throws:

NullPointerException - If buf is null.

IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than buf.length - off

ZipException - if the compressed input data is corrupt.

IOException - if an I/O error has occurred.

See Also:

• FilterInputStream.in

close

public void close()
           throws IOException

Closes this input stream and releases any system resources associated with the stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InflaterInputStream

Throws:

IOException - if an I/O error has occurred

See Also:

• FilterInputStream.in