webplugin.aclib.codec

Class AbstractDecoder

java.lang.Object

webplugin.aclib.codec.AbstractDecoder

Direct Known Subclasses:

ImageInputStreamDecoder, StreamDecoder

public abstract class AbstractDecoder
extends Object

Byte stream decoder for 1, 2, and 4 byte values in big or little endian format.

Author:

© Christian Treber, ct@ctreber.com

Field Summary

Fields

Modifier and Type	Field and Description
protected long	_pos
static int	BIG_ENDIAN Highest order byte comes first.
static int	LITTLE_ENDIAN Lowest order byte comes first.

Constructor Summary

Constructors

Constructor and Description
AbstractDecoder()

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	close() Call when done with decoder.
long	getPos()
abstract byte[]	readBytes(long pBytes, byte[] pBuffer) Implemented by a specific decoder.
short	readUInt1()
int	readUInt2()
long	readUInt4()
protected long	readValue(int pBytes)
abstract void	seek(long pPos)
void	setEndianess(int pEndianess)

Methods inherited from class java.lang.Object

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

Field Detail

BIG_ENDIAN

public static final int BIG_ENDIAN

Highest order byte comes first.

See Also:

Constant Field Values

LITTLE_ENDIAN

public static final int LITTLE_ENDIAN

Lowest order byte comes first.

See Also:

Constant Field Values

_pos

protected long _pos

Constructor Detail

AbstractDecoder

public AbstractDecoder()

Method Detail

readUInt1

public short readUInt1()
                throws IOException

Returns:

A one byte value (aka BYTE, unsigned char)

Throws:

IOException

readUInt2

public int readUInt2()
              throws IOException

Returns:

A two byte value (aka WORD, unsigned short)

Throws:

IOException

readUInt4

public long readUInt4()
               throws IOException

Returns:

A four byte value (aka DWORD, unsigned long).

Throws:

IOException

setEndianess

public void setEndianess(int pEndianess)

Parameters:

pEndianess - The byte order

See Also:

BIG_ENDIAN, LITTLE_ENDIAN

getPos

public long getPos()

Returns:

Current position in file

seek

public abstract void seek(long pPos)
                   throws IOException

Parameters:

pPos - Position to advance to. Nothing will happen if the position has already been passed.

Throws:

IOException

readBytes

public abstract byte[] readBytes(long pBytes,
               byte[] pBuffer)
                          throws IOException

Implemented by a specific decoder.

Parameters:

pBytes - Bytes to read

pBuffer - The buffer to write the read bytes to. If null, a buffer is reserved.

Returns:

Array with the bytes read.

Throws:

IOException

readValue

protected long readValue(int pBytes)
                  throws IOException

Throws:

IOException

close

public abstract void close()
                    throws IOException

Call when done with decoder.

Throws:

IOException