Package java.util.zip

Class InflaterInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.util.zip.InflaterInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

GZIPInputStream, ZipInputStream

public class InflaterInputStream
extends FilterInputStream

This class provides an implementation of FilterInputStream that decompresses data that was compressed using the DEFLATE algorithm (see specification). Basically it wraps the Inflater class and takes care of the buffering.

See Also:

Inflater, DeflaterOutputStream

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	buf	The input buffer used for decompression.
protected Inflater	inf	The inflater used for this stream.
protected int	len	The length of the buffer.

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
InflaterInputStream(InputStream is)	This is the most basic constructor.
InflaterInputStream(InputStream is, Inflater inflater)	This constructor lets you pass a specifically initialized Inflater, for example one that expects no ZLIB header.
InflaterInputStream(InputStream is, Inflater inflater, int bufferSize)	This constructor lets you specify both the Inflater as well as the internal buffer size to be used.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns 0 when when this stream has exhausted its input; and 1 otherwise.
void	close()	Closes the input stream.
protected void	fill()	Fills the input buffer with data to be decompressed.
void	mark(int readlimit)	Marks the current position in the stream.
boolean	markSupported()	Returns whether the receiver implements mark semantics.
int	read()	Reads a single byte of decompressed data.
int	read(byte[] buffer, int byteOffset, int byteCount)	Reads up to byteCount bytes of decompressed data and stores it in buffer starting at byteOffset.
void	reset()	Reset the position of the stream to the last marked position.
long	skip(long byteCount)	Skips up to byteCount bytes of uncompressed data.

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

inf

protected Inflater inf

The inflater used for this stream.

buf

protected byte[] buf

The input buffer used for decompression.

len

protected int len

The length of the buffer.

Constructor Details

InflaterInputStream

public InflaterInputStream(InputStream is)

This is the most basic constructor. You only need to pass the InputStream from which the compressed data is to be read from. Default settings for the Inflater and internal buffer are be used. In particular the Inflater expects a ZLIB header from the input stream.

Parameters:

is - the InputStream to read data from.

InflaterInputStream

public InflaterInputStream(InputStream is, Inflater inflater)

This constructor lets you pass a specifically initialized Inflater, for example one that expects no ZLIB header.

Parameters:

is - the InputStream to read data from.

inflater - the specific Inflater for decompressing data.

InflaterInputStream

public InflaterInputStream(InputStream is, Inflater inflater, int bufferSize)

This constructor lets you specify both the Inflater as well as the internal buffer size to be used.

Parameters:

is - the InputStream to read data from.

inflater - the specific Inflater for decompressing data.

bufferSize - the size to be used for the internal buffer.

Method Details

read

public int read() throws IOException

Reads a single byte of decompressed data.

Overrides:

read in class FilterInputStream

Returns:

the byte read.

Throws:

IOException - if an error occurs reading the byte.

read

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

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 FilterInputStream

Throws:

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

fill

protected void fill() throws IOException

Fills the input buffer with data to be decompressed.

Throws:

IOException - if an IOException occurs.

skip

public long skip(long byteCount) throws IOException

Skips up to byteCount bytes of uncompressed data.

Overrides:

skip in class FilterInputStream

Parameters:

byteCount - the number of bytes to skip.

Returns:

the number of uncompressed bytes skipped.

Throws:

IllegalArgumentException - if byteCount < 0.

IOException - if an error occurs skipping.

See Also:

FilterInputStream.mark(int), FilterInputStream.reset()

available

public int available() throws IOException

Returns 0 when when this stream has exhausted its input; and 1 otherwise. A result of 1 does not guarantee that further bytes can be returned, with or without blocking.

Although consistent with the RI, this behavior is inconsistent with InputStream.available(), and violates the Liskov Substitution Principle. This method should not be used.

Overrides:

available in class FilterInputStream

Returns:

0 if no further bytes are available. Otherwise returns 1, which suggests (but does not guarantee) that additional bytes are available.

Throws:

IOException - if this stream is closed or an error occurs

close

public void close() throws IOException

Closes the input stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterInputStream

Throws:

IOException - If an error occurs closing the input stream.

mark

public void mark(int readlimit)

Marks the current position in the stream. This implementation overrides the super type implementation to do nothing at all.

Overrides:

mark in class FilterInputStream

Parameters:

readlimit - of no use.

See Also:

FilterInputStream.markSupported(), FilterInputStream.reset()

reset

public void reset() throws IOException

Reset the position of the stream to the last marked position. This implementation overrides the supertype implementation and always throws an IOException when called.

Overrides:

reset in class FilterInputStream

Throws:

IOException - if the method is called

See Also:

FilterInputStream.mark(int), FilterInputStream.markSupported()

markSupported

public boolean markSupported()

Returns whether the receiver implements mark semantics. This type does not support mark(), so always responds false.

Overrides:

markSupported in class FilterInputStream

Returns:

false, always

See Also:

FilterInputStream.mark(int), FilterInputStream.reset(), FilterInputStream.skip(long)