java.util.zip

Class DeflaterInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.util.zip.DeflaterInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class DeflaterInputStream
extends FilterInputStream

An InputStream filter to compress data. Callers read compressed data in the "deflate" format from the uncompressed underlying stream.

Since:

1.6

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	buf
protected Deflater	def

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor and Description
DeflaterInputStream(InputStream in) Constructs a DeflaterInputStream with a new Deflater and an implementation-defined default internal buffer size.
DeflaterInputStream(InputStream in, Deflater deflater) Constructs a DeflaterInputStream with the given Deflater and an implementation-defined default internal buffer size.
DeflaterInputStream(InputStream in, Deflater deflater, int bufferSize) Constructs a DeflaterInputStream with the given Deflater and given internal buffer size.

Method Summary

Modifier and Type	Method and Description
int	available() Returns 0 when when this stream has exhausted its input; and 1 otherwise.
void	close() Closes the underlying input stream and discards any remaining uncompressed data.
void	mark(int limit) This operation is not supported and does nothing.
boolean	markSupported() Returns false because DeflaterInputStream does not support mark/reset.
int	read() Reads a byte from the compressed input stream.
int	read(byte[] buffer, int byteOffset, int byteCount) Reads up to byteCount bytes of compressed data into a byte buffer.
void	reset() This operation is not supported and throws IOException.
long	skip(long byteCount) Skips byteCount bytes in this stream.

Methods inherited from class java.io.InputStream

nullInputStream, read, readAllBytes, readNBytes, readNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Detail

def

protected final Deflater def

buf

protected final byte[] buf

Constructor Detail

DeflaterInputStream

public DeflaterInputStream(InputStream in)

Constructs a DeflaterInputStream with a new Deflater and an implementation-defined default internal buffer size. in is a source of uncompressed data, and this stream will be a source of compressed data.

Parameters:

in - the source InputStream

DeflaterInputStream

public DeflaterInputStream(InputStream in,
                           Deflater deflater)

Constructs a DeflaterInputStream with the given Deflater and an implementation-defined default internal buffer size. in is a source of uncompressed data, and this stream will be a source of compressed data.

Parameters:

in - the source InputStream

deflater - the Deflater to be used for compression

DeflaterInputStream

public DeflaterInputStream(InputStream in,
                           Deflater deflater,
                           int bufferSize)

Constructs a DeflaterInputStream with the given Deflater and given internal buffer size. in is a source of uncompressed data, and this stream will be a source of compressed data.

Parameters:

in - the source InputStream

deflater - the Deflater to be used for compression

bufferSize - the length in bytes of the internal buffer

Method Detail

close

public void close()
           throws IOException

Closes the underlying input stream and discards any remaining uncompressed data.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class FilterInputStream

Throws:

IOException - if an error occurs while closing this stream.

read

public int read()
         throws IOException

Reads a byte from the compressed input stream. The result will be a byte of compressed data corresponding to an uncompressed byte or bytes read from the underlying stream.

Overrides:

read in class FilterInputStream

Returns:

the byte or -1 if the end of the stream has been reached.

Throws:

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

read

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

Reads up to byteCount bytes of compressed data into a byte buffer. The result will be bytes of compressed data corresponding to an uncompressed byte or bytes read from the underlying stream. Returns the number of bytes read or -1 if the end of the compressed input stream has been reached.

Overrides:

read in class FilterInputStream

Throws:

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

skip

public long skip(long byteCount)
          throws IOException

Skips byteCount bytes in this stream. Subsequent calls to read will not return these bytes unless reset is used. This implementation skips byteCount bytes in the filtered stream.

Note: if n > Integer.MAX_VALUE, this stream will only attempt to skip Integer.MAX_VALUE bytes.

Overrides:

skip in class FilterInputStream

Returns:

the number of bytes actually skipped.

Throws:

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

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

markSupported

public boolean markSupported()

Returns false because DeflaterInputStream does not support mark/reset.

Overrides:

markSupported in class FilterInputStream

Returns:

true if mark() and reset() are supported, false otherwise.

See Also:

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

mark

public void mark(int limit)

This operation is not supported and does nothing.

Overrides:

mark in class FilterInputStream

Parameters:

limit - the number of bytes that can be read from this stream before the mark is invalidated.

See Also:

FilterInputStream.markSupported(), FilterInputStream.reset()

reset

public void reset()
           throws IOException

This operation is not supported and throws IOException.

Overrides:

reset in class FilterInputStream

Throws:

IOException - if this stream is already closed, no mark has been set or the mark is no longer valid because more than readlimit bytes have been read since setting the mark.

See Also:

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