Package com.dannemann.stringcompressor

Class FiveBitAsciiCompressor

java.lang.Object

com.dannemann.stringcompressor.AsciiCompressor

com.dannemann.stringcompressor.FiveBitAsciiCompressor

public class FiveBitAsciiCompressor
extends AsciiCompressor

Performs 5-bit-per-ASCII-character encoding and decoding.

Compression rate: 38%

Field Summary

Fields

Modifier and Type	Field	Description
static final byte[]	DEFAULT_5BIT_CHARSET
static final byte[]	DEFAULT_5BIT_CHARSET_LOWERCASE

Fields inherited from class com.dannemann.stringcompressor.AsciiCompressor

preserveOriginal, supportedCharset, throwException

Constructor Summary

Constructors

Constructor	Description
FiveBitAsciiCompressor()
FiveBitAsciiCompressor(boolean throwException)
FiveBitAsciiCompressor(byte[] supportedCharset)

Method Summary

Modifier and Type	Method	Description
final byte[]	compress(byte[] str)	Packs characters into chunks of 5 bits.
final byte[]	decompress(byte[] compressed)	Restores the original string from data compressed by AsciiCompressor.compress(byte[]).
protected void	validateSupportedCharset(byte[] supportedCharset)

Methods inherited from class com.dannemann.stringcompressor.AsciiCompressor

encode, setPreserveOriginal, setThrowException, standardCharsetValidation

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_5BIT_CHARSET

public static final byte[] DEFAULT_5BIT_CHARSET

DEFAULT_5BIT_CHARSET_LOWERCASE

public static final byte[] DEFAULT_5BIT_CHARSET_LOWERCASE

Constructor Details

FiveBitAsciiCompressor

public FiveBitAsciiCompressor()

FiveBitAsciiCompressor

public FiveBitAsciiCompressor(byte[] supportedCharset)

FiveBitAsciiCompressor

public FiveBitAsciiCompressor(boolean throwException)

Method Details

compress

public final byte[] compress(byte[] str)

Packs characters into chunks of 5 bits. Supports a set of 32 different characters (00000 to 11111).

Compression rate: 38%

See DEFAULT_5BIT_CHARSET for the default set of supported characters.

Specified by:

compress in class AsciiCompressor

Parameters:

str - string to be compressed.

Returns:

A compressed byte array.

decompress

public final byte[] decompress(byte[] compressed)

Restores the original string from data compressed by AsciiCompressor.compress(byte[]).

Specified by:

decompress in class AsciiCompressor

Parameters:

compressed - The compressed string byte array.

Returns:

A decompressed string byte array.

validateSupportedCharset

protected void validateSupportedCharset(byte[] supportedCharset)

Specified by:

validateSupportedCharset in class AsciiCompressor