net.wimpi.pim.util
Class Base64

java.lang.Object
  |
  +--net.wimpi.pim.util.Base64

public class Base64

extends java.lang.Object

This class provides methods for encoding and decoding data in MIME base64 format.

The input to the encode methods is always a byte array. Strictly speaking the output represents a sequence of characters, but since these characters are from a subset of both the Unicode and ASCII character repertoires, it is possible to express the output either as a String or as a byte array.

References:

1. RFC 2045, Multipurpose Internet Mail Extensions (MIME) Part One, Format of Internet Message Bodies, "Section 6.8 Base64 Content-Transfer-Encoding," http://www.imc.org/rfc2045

Version:

Distributed with 0.1 (22/07/2003)

Author:

Jill Baker, David Hopwood

Field Summary

protected static byte[]	dec_table A static array that maps ASCII code points to a 6-bit integer, or -1 for an invalid code point.
protected static char[]	enc_table A static array that maps 6-bit integers to a specific char.

Method Summary

static byte[]	decode(byte[] data) Decodes a byte array containing base64-encoded ASCII.
static byte[]	encode(byte[] data) Encodes data as a byte array using base64 encoding.

Methods inherited from class java.lang.Object

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

Field Detail

enc_table

protected static final char[] enc_table

A static array that maps 6-bit integers to a specific char.

dec_table

protected static final byte[] dec_table

A static array that maps ASCII code points to a 6-bit integer, or -1 for an invalid code point.

Method Detail

encode

public static final byte[] encode(byte[] data)

Encodes data as a byte array using base64 encoding. The characters 'A'-'Z', 'a'-'z', '0'-'9', '+', '/', and '=' in the output are mapped to their ASCII code points. Line breaks in the output are represented as CR LF (codes 13 and 10).

Returns:

the encoded byte array.

decode

public static final byte[] decode(byte[] data)

Decodes a byte array containing base64-encoded ASCII. Characters with ASCII code points <= 32 (this includes whitespace and newlines) are ignored.

Returns:

the decoded data.

Throws:

java.lang.IllegalArgumentException - if data contains invalid characters, i.e. not codes 0-32, 'A'-'Z', 'a'-'z', '+', '/'. or '=', or is incorrectly padded.