org.apache.commons.codec.binary

Class Base64

public class Base64 extends Object implements BinaryEncoder, BinaryDecoder

Provides Base64 encoding and decoding as defined by RFC 2045.

This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.

Since: 1.0-dev

Version: $Id: Base64.java 130370 2004-05-24 00:25:22Z ggregory $

Author: Apache Software Foundation

See Also: RFC 2045

Field Summary
static byte[]base64Alphabet
static intBASELENGTH
The base length.
static byte[]CHUNK_SEPARATOR
Chunk separator per RFC 2045 section 2.1.
static intCHUNK_SIZE
Chunk size per RFC 2045 section 6.8.
static intEIGHTBIT
Used to calculate the number of bits in a byte.
static intFOURBYTE
Used to get the number of Quadruples.
static byte[]lookUpBase64Alphabet
static intLOOKUPLENGTH
Lookup length.
static bytePAD
Byte used to pad output.
static intSIGN
Used to test the sign of a byte.
static intSIXTEENBIT
Used when encoding something which has fewer than 24 bits.
static intTWENTYFOURBITGROUP
Used to determine how many bits data contains.
Method Summary
Objectdecode(Object pObject)
Decodes an Object using the base64 algorithm.
byte[]decode(byte[] pArray)
Decodes a byte[] containing containing characters in the Base64 alphabet.
static byte[]decodeBase64(byte[] base64Data)
Decodes Base64 data into octects
static byte[]discardNonBase64(byte[] data)
Discards any characters outside of the base64 alphabet, per the requirements on page 25 of RFC 2045 - "Any characters outside of the base64 alphabet are to be ignored in base64 encoded data."
static byte[]discardWhitespace(byte[] data)
Discards any whitespace from a base-64 encoded block.
Objectencode(Object pObject)
Encodes an Object using the base64 algorithm.
byte[]encode(byte[] pArray)
Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
static byte[]encodeBase64(byte[] binaryData)
Encodes binary data using the base64 algorithm but does not chunk the output.
static byte[]encodeBase64(byte[] binaryData, boolean isChunked)
Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
static byte[]encodeBase64Chunked(byte[] binaryData)
Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
static booleanisArrayByteBase64(byte[] arrayOctect)
Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
static booleanisBase64(byte octect)

Field Detail

base64Alphabet

private static byte[] base64Alphabet

BASELENGTH

static final int BASELENGTH
The base length.

CHUNK_SEPARATOR

static final byte[] CHUNK_SEPARATOR
Chunk separator per RFC 2045 section 2.1.

See Also: RFC 2045 section 2.1

CHUNK_SIZE

static final int CHUNK_SIZE
Chunk size per RFC 2045 section 6.8.

The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.

See Also: RFC 2045 section 6.8

EIGHTBIT

static final int EIGHTBIT
Used to calculate the number of bits in a byte.

FOURBYTE

static final int FOURBYTE
Used to get the number of Quadruples.

lookUpBase64Alphabet

private static byte[] lookUpBase64Alphabet

LOOKUPLENGTH

static final int LOOKUPLENGTH
Lookup length.

PAD

static final byte PAD
Byte used to pad output.

SIGN

static final int SIGN
Used to test the sign of a byte.

SIXTEENBIT

static final int SIXTEENBIT
Used when encoding something which has fewer than 24 bits.

TWENTYFOURBITGROUP

static final int TWENTYFOURBITGROUP
Used to determine how many bits data contains.

Method Detail

decode

public Object decode(Object pObject)
Decodes an Object using the base64 algorithm. This method is provided in order to satisfy the requirements of the Decoder interface, and will throw a DecoderException if the supplied object is not of type byte[].

Parameters: pObject Object to decode

Returns: An object (of type byte[]) containing the binary data which corresponds to the byte[] supplied.

Throws: DecoderException if the parameter supplied is not of type byte[]

decode

public byte[] decode(byte[] pArray)
Decodes a byte[] containing containing characters in the Base64 alphabet.

Parameters: pArray A byte array containing Base64 character data

Returns: a byte array containing binary data

decodeBase64

public static byte[] decodeBase64(byte[] base64Data)
Decodes Base64 data into octects

Parameters: base64Data Byte array containing Base64 data

Returns: Array containing decoded data.

discardNonBase64

static byte[] discardNonBase64(byte[] data)
Discards any characters outside of the base64 alphabet, per the requirements on page 25 of RFC 2045 - "Any characters outside of the base64 alphabet are to be ignored in base64 encoded data."

Parameters: data The base-64 encoded data to groom

Returns: The data, less non-base64 characters (see RFC 2045).

discardWhitespace

static byte[] discardWhitespace(byte[] data)
Discards any whitespace from a base-64 encoded block.

Parameters: data The base-64 encoded data to discard the whitespace from.

Returns: The data, less whitespace (see RFC 2045).

encode

public Object encode(Object pObject)
Encodes an Object using the base64 algorithm. This method is provided in order to satisfy the requirements of the Encoder interface, and will throw an EncoderException if the supplied object is not of type byte[].

Parameters: pObject Object to encode

Returns: An object (of type byte[]) containing the base64 encoded data which corresponds to the byte[] supplied.

Throws: EncoderException if the parameter supplied is not of type byte[]

encode

public byte[] encode(byte[] pArray)
Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.

Parameters: pArray a byte array containing binary data

Returns: A byte array containing only Base64 character data

encodeBase64

public static byte[] encodeBase64(byte[] binaryData)
Encodes binary data using the base64 algorithm but does not chunk the output.

Parameters: binaryData binary data to encode

Returns: Base64 characters

encodeBase64

public static byte[] encodeBase64(byte[] binaryData, boolean isChunked)
Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.

Parameters: binaryData Array containing binary data to encode. isChunked if isChunked is true this encoder will chunk the base64 output into 76 character blocks

Returns: Base64-encoded data.

encodeBase64Chunked

public static byte[] encodeBase64Chunked(byte[] binaryData)
Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks

Parameters: binaryData binary data to encode

Returns: Base64 characters chunked in 76 character blocks

isArrayByteBase64

public static boolean isArrayByteBase64(byte[] arrayOctect)
Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.

Parameters: arrayOctect byte array to test

Returns: true if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; false, otherwise

isBase64

private static boolean isBase64(byte octect)
commons-codec version 1.3 - Copyright © 2002-2004 - Apache Software Foundation