org.codehaus.plexus.util
Class Base64

java.lang.Object
  extended by org.codehaus.plexus.util.Base64

public class Base64
extends java.lang.Object

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 5958 2007-02-28 10:29:55Z olamy $
Author:
Apache Software Foundation
See Also:
RFC 2045

Field Summary
private static byte[] base64Alphabet
          Contains the Base64 values 0 through 63 accessed by using character encodings as indices.
(package private) static int BASELENGTH
          The base length.
(package private) static byte[] CHUNK_SEPARATOR
          Chunk separator per RFC 2045 section 2.1.
(package private) static int CHUNK_SIZE
          Chunk size per RFC 2045 section 6.8.
(package private) static int EIGHTBIT
          Used to calculate the number of bits in a byte.
(package private) static int FOURBYTE
          Used to get the number of Quadruples.
private static byte[] lookUpBase64Alphabet
           Contains the Base64 encodings A through Z, followed by a through z, followed by 0 through 9, followed by +, and /.
(package private) static int LOOKUPLENGTH
          Lookup length.
(package private) static byte PAD
          Byte used to pad output.
(package private) static int SIGN
          Used to test the sign of a byte.
(package private) static int SIXTEENBIT
          Used when encoding something which has fewer than 24 bits.
(package private) static int TWENTYFOURBITGROUP
          Used to determine how many bits data contains.
 
Constructor Summary
Base64()
           
 
Method Summary
 byte[] decode(byte[] pArray)
          Decodes a byte[] containing containing characters in the Base64 alphabet.
static byte[] decodeBase64(byte[] base64Data)
          Decodes Base64 data into octects
(package private) 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."
(package private) static byte[] discardWhitespace(byte[] data)
          Discards any whitespace from a base-64 encoded block.
 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 boolean isArrayByteBase64(byte[] arrayOctect)
          Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
private static boolean isBase64(byte octect)
          Returns whether or not the octect is in the base 64 alphabet.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

CHUNK_SIZE

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

The 76 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.

See Also:
RFC 2045 section 6.8, Constant Field Values

CHUNK_SEPARATOR

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

See Also:
RFC 2045 section 2.1

BASELENGTH

static final int BASELENGTH
The base length.

See Also:
Constant Field Values

LOOKUPLENGTH

static final int LOOKUPLENGTH
Lookup length.

See Also:
Constant Field Values

EIGHTBIT

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

See Also:
Constant Field Values

SIXTEENBIT

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

See Also:
Constant Field Values

TWENTYFOURBITGROUP

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

See Also:
Constant Field Values

FOURBYTE

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

See Also:
Constant Field Values

SIGN

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

See Also:
Constant Field Values

PAD

static final byte PAD
Byte used to pad output.

See Also:
Constant Field Values

base64Alphabet

private static byte[] base64Alphabet
Contains the Base64 values 0 through 63 accessed by using character encodings as indices.

For example, base64Alphabet['+'] returns 62.

The value of undefined encodings is -1.


lookUpBase64Alphabet

private static byte[] lookUpBase64Alphabet

Contains the Base64 encodings A through Z, followed by a through z, followed by 0 through 9, followed by +, and /.

This array is accessed by using character values as indices.

For example, lookUpBase64Alphabet[62] returns '+'.

Constructor Detail

Base64

public Base64()
Method Detail

isBase64

private static boolean isBase64(byte octect)
Returns whether or not the octect is in the base 64 alphabet.

Parameters:
octect - The value to test
Returns:
true if the value is defined in the the base 64 alphabet, false otherwise.

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

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

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

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

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 true this encoder will chunk the base64 output into 76 character blocks
Returns:
Base64-encoded 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.

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).

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).

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