DeflaterInputStream

public class DeflaterInputStream extends FilterInputStream

Implements an input stream filter for compressing data in the "deflate" compression format.

Field Summary

protected final byte[] buf Input buffer for reading compressed data.
protected final Deflater def Compressor for this stream.

Inherited Field Summary

Public Constructor Summary

DeflaterInputStream(InputStream in)
Creates a new input stream with a default compressor and buffer size.
DeflaterInputStream(InputStream in, Deflater defl)
Creates a new input stream with the specified compressor and a default buffer size.
DeflaterInputStream(InputStream in, Deflater defl, int bufLen)
Creates a new input stream with the specified compressor and buffer size.

Public Method Summary

int
available()
Returns 0 after EOF has been reached, otherwise always return 1.
void
close()
Closes this input stream and its underlying input stream, discarding any pending uncompressed data.
void
mark(int limit)
This operation is not supported.
boolean
markSupported()
Always returns false because this input stream does not support the mark() and reset() methods.
int
read()
Reads a single byte of compressed data from the input stream.
int
read(byte[] b, int off, int len)
Reads compressed data into a byte array.
void
reset()
This operation is not supported.
long
skip(long n)
Skips over and discards data from the input stream.

Inherited Method Summary

Fields

protected final byte[] buf

Input buffer for reading compressed data.

protected final Deflater def

Compressor for this stream.

Public Constructors

public DeflaterInputStream (InputStream in)

Creates a new input stream with a default compressor and buffer size.

Parameters
in input stream to read the uncompressed data to
Throws
NullPointerException if in is null

public DeflaterInputStream (InputStream in, Deflater defl)

Creates a new input stream with the specified compressor and a default buffer size.

Parameters
in input stream to read the uncompressed data to
defl compressor ("deflater") for this stream
Throws
NullPointerException if in or defl is null

public DeflaterInputStream (InputStream in, Deflater defl, int bufLen)

Creates a new input stream with the specified compressor and buffer size.

Parameters
in input stream to read the uncompressed data to
defl compressor ("deflater") for this stream
bufLen compression buffer size
Throws
IllegalArgumentException if bufLen is <= 0
NullPointerException if in or defl is null

Public Methods

public int available ()

Returns 0 after EOF has been reached, otherwise always return 1.

Programs should not count on this method to return the actual number of bytes that could be read without blocking

Returns
  • zero after the end of the underlying input stream has been reached, otherwise always returns 1
Throws
IOException if an I/O error occurs or if this stream is already closed

public void close ()

Closes this input stream and its underlying input stream, discarding any pending uncompressed data.

Throws
IOException if an I/O error occurs

public void mark (int limit)

This operation is not supported.

Parameters
limit maximum bytes that can be read before invalidating the position marker

public boolean markSupported ()

Always returns false because this input stream does not support the mark() and reset() methods.

Returns
  • false, always

public int read ()

Reads a single byte of compressed data from the input stream. This method will block until some input can be read and compressed.

Returns
  • a single byte of compressed data, or -1 if the end of the uncompressed input stream is reached
Throws
IOException if an I/O error occurs or if this stream is already closed

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

Reads compressed data into a byte array. This method will block until some input can be read and compressed.

Parameters
b buffer into which the data is read
off starting offset of the data within b
len maximum number of compressed bytes to read into b
Returns
  • the actual number of bytes read, or -1 if the end of the uncompressed input stream is reached
Throws
IndexOutOfBoundsException if len > b.length - off
IOException if an I/O error occurs or if this input stream is already closed

public void reset ()

This operation is not supported.

Throws
IOException always thrown

public long skip (long n)

Skips over and discards data from the input stream. This method may block until the specified number of bytes are read and skipped. Note: While n is given as a long, the maximum number of bytes which can be skipped is Integer.MAX_VALUE.

Parameters
n number of bytes to be skipped
Returns
  • the actual number of bytes skipped
Throws
IOException if an I/O error occurs or if this stream is already closed