com.siemens.ct.exi.core.io.compression

Class EXIInflaterInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

com.siemens.ct.exi.core.io.compression.EXIInflaterInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class EXIInflaterInputStream
extends FilterInputStream

An inflate stream with the ability to pushback data which the inflater read beyond.

Note: Code borrowed from java.util.zip.InflaterInputStream and pushback support added.

Author:

Daniel.Peintner.EXT@siemens.com, Richard.Kuntschke@siemens.com

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	buf Input buffer for decompression.
protected Inflater	inf Decompressor for this stream.
protected int	len Length of input buffer.

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor and Description
EXIInflaterInputStream(PushbackInputStream in, Inflater inf, int size) Creates a new input stream with the specified decompressor and buffer size.

Method Summary

Modifier and Type	Method and Description
int	available() Returns 0 after EOF has been reached, otherwise always return 1.
void	close() Closes this input stream and releases any system resources associated with the stream.
protected void	fill() Fills input buffer with more data to decompress.
void	mark(int readlimit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
void	pushbackAndReset()
int	read() Reads a byte of uncompressed data.
int	read(byte[] b, int off, int len) Reads uncompressed data into an array of bytes.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n) Skips specified number of bytes of uncompressed data.

Methods inherited from class java.io.FilterInputStream

read

Methods inherited from class java.lang.Object

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

Field Detail

inf

protected Inflater inf

Decompressor for this stream.

buf

protected byte[] buf

Input buffer for decompression.

len

protected int len

Length of input buffer.

Constructor Detail

EXIInflaterInputStream

public EXIInflaterInputStream(PushbackInputStream in,
                              Inflater inf,
                              int size)

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

Parameters:

in - the input stream

inf - the decompressor ("inflater")

size - the input buffer size

Throws:

IllegalArgumentException - if size is ≤ 0

Method Detail

pushbackAndReset

public void pushbackAndReset()
                      throws IOException

Throws:

IOException

read

public int read()
         throws IOException

Reads a byte of uncompressed data. This method will block until enough input is available for decompression.

Overrides:

read in class FilterInputStream

Returns:

the byte read, or -1 if end of compressed input is reached

Throws:

IOException - if an I/O error has occurred

read

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

Reads uncompressed data into an array of bytes. This method will block until some input can be decompressed.

Overrides:

read in class FilterInputStream

Parameters:

b - the buffer into which the data is read

off - the start offset of the data

len - the maximum number of bytes read

Returns:

the actual number of bytes read, or -1 if the end of the compressed input is reached or a preset dictionary is needed

Throws:

ZipException - if a ZIP format error has occurred

IOException - if an I/O error has occurred

available

public int available()
              throws IOException

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.

Overrides:

available in class FilterInputStream

Returns:

1 before EOF and 0 after EOF.

Throws:

IOException - if an I/O error occurs.

skip

public long skip(long n)
          throws IOException

Skips specified number of bytes of uncompressed data.

Overrides:

skip in class FilterInputStream

Parameters:

n - the number of bytes to skip

Returns:

the actual number of bytes skipped.

Throws:

IOException - if an I/O error has occurred

IllegalArgumentException - if n < 0

close

public void close()
           throws IOException

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

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class FilterInputStream

Throws:

IOException - if an I/O error has occurred

fill

protected void fill()
             throws IOException

Fills input buffer with more data to decompress.

Throws:

IOException - if an I/O error has occurred

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. The markSupported method of InflaterInputStream returns false.

Overrides:

markSupported in class FilterInputStream

Returns:

a boolean indicating if this stream type supports the mark and reset methods.

See Also:

InputStream.mark(int), InputStream.reset()

mark

public void mark(int readlimit)

Marks the current position in this input stream.

The mark method of InflaterInputStream does nothing.

Overrides:

mark in class FilterInputStream

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

See Also:

InputStream.reset()

reset

public void reset()
           throws IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

The method reset for class InflaterInputStream does nothing except throw an IOException.

Overrides:

reset in class FilterInputStream

Throws:

IOException - if this method is invoked.

See Also:

InputStream.mark(int), IOException