org.apache.commons.net.util
Class Base64

java.lang.Object
  org.apache.commons.net.util.Base64

public class Base64
extends 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.

The class can be parameterized in the following manner with various constructors:

• URL-safe mode: Default off.
• Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
• Line separator: Default is CRLF ("\r\n")

Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).

Since:

2.2

Version:

$Id: Base64.java 1407341 2012-11-09 01:31:00Z ggregory $

Author:

Apache Software Foundation

See Also:

RFC 2045

Constructor Summary

Base64()
Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

Base64(boolean urlSafe)
Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.

Base64(int lineLength)
Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

Base64(int lineLength, byte[] lineSeparator)
Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

Base64(int lineLength, byte[] lineSeparator, boolean urlSafe)
Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

Method Summary

byte[]	decode(byte[] pArray) Decodes a byte[] containing containing characters in the Base64 alphabet.
byte[]	decode(String pArray) Decodes a String containing containing characters in the Base64 alphabet.
static byte[]	decodeBase64(byte[] base64Data) Decodes Base64 data into octets
static byte[]	decodeBase64(String base64String) Decodes a Base64 String into octets
static BigInteger	decodeInteger(byte[] pArray) Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
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[]	encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
static byte[]	encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) 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 String	encodeBase64String(byte[] binaryData) Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF.
static String	encodeBase64String(byte[] binaryData, boolean useChunking) Encodes binary data using the base64 algorithm.
static String	encodeBase64StringUnChunked(byte[] binaryData) Encodes binary data using the base64 algorithm, without using chunking.
static byte[]	encodeBase64URLSafe(byte[] binaryData) Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output.
static String	encodeBase64URLSafeString(byte[] binaryData) Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output.
static byte[]	encodeInteger(BigInteger bigInt) Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
String	encodeToString(byte[] pArray) Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet.
static boolean	isArrayByteBase64(byte[] arrayOctet) Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
static boolean	isBase64(byte octet) Returns whether or not the octet is in the base 64 alphabet.
boolean	isUrlSafe() Returns our current encode mode.

Methods inherited from class java.lang.Object

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

Constructor Detail

Base64

public Base64()

Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.

When decoding all variants are supported.

Base64

public Base64(boolean urlSafe)

Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.

When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.

When decoding all variants are supported.

Parameters:

urlSafe - if true, URL-safe encoding is used. In most cases this should be set to false.

Since:

1.4

Base64

public Base64(int lineLength)

Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.

Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.

When decoding all variants are supported.

Parameters:

lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.

Since:

1.4

Base64

public Base64(int lineLength,
              byte[] lineSeparator)

Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE.

Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.

When decoding all variants are supported.

Parameters:

lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.

lineSeparator - Each line of encoded data will end with this sequence of bytes.

Throws:

IllegalArgumentException - Thrown when the provided lineSeparator included some base64 characters.

Since:

1.4

Base64

public Base64(int lineLength,
              byte[] lineSeparator,
              boolean urlSafe)

Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE.

Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.

When decoding all variants are supported.

Parameters:

lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.

lineSeparator - Each line of encoded data will end with this sequence of bytes.

urlSafe - Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode operations. Decoding seamlessly handles both modes.

Throws:

IllegalArgumentException - The provided lineSeparator included some base64 characters. That's not going to work!

Since:

1.4

Method Detail

isUrlSafe

public boolean isUrlSafe()

Returns our current encode mode. True if we're URL-SAFE, false otherwise.

Returns:

true if we're in URL-SAFE mode, false otherwise.

Since:

1.4

isBase64

public static boolean isBase64(byte octet)

Returns whether or not the octet is in the base 64 alphabet.

Parameters:

octet - The value to test

Returns:

true if the value is defined in the the base 64 alphabet, false otherwise.

Since:

1.4

isArrayByteBase64

public static boolean isArrayByteBase64(byte[] arrayOctet)

Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid.

Parameters:

arrayOctet - 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:

byte[] containing Base64 characters in their UTF-8 representation.

encodeBase64String

public static String encodeBase64String(byte[] binaryData)

Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF.

For a non-chunking version, see encodeBase64StringUnChunked(byte[]).

Parameters:

binaryData - binary data to encode

Returns:

String containing Base64 characters.

Since:

1.4

encodeBase64StringUnChunked

public static String encodeBase64StringUnChunked(byte[] binaryData)

Encodes binary data using the base64 algorithm, without using chunking.

For a chunking version, see encodeBase64String(byte[]).

Parameters:

binaryData - binary data to encode

Returns:

String containing Base64 characters.

Since:

3.2

encodeBase64String

public static String encodeBase64String(byte[] binaryData,
                                        boolean useChunking)

Encodes binary data using the base64 algorithm.

Parameters:

binaryData - binary data to encode

useChunking - whether to split the output into chunks

Returns:

String containing Base64 characters.

Since:

3.2

encodeBase64URLSafe

public static byte[] encodeBase64URLSafe(byte[] binaryData)

Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + and / characters.

Parameters:

binaryData - binary data to encode

Returns:

byte[] containing Base64 characters in their UTF-8 representation.

Since:

1.4

encodeBase64URLSafeString

public static String encodeBase64URLSafeString(byte[] binaryData)

Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + and / characters.

Parameters:

binaryData - binary data to encode

Returns:

String containing Base64 characters

Since:

1.4

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(String pArray)

Decodes a String containing containing characters in the Base64 alphabet.

Parameters:

pArray - A String containing Base64 character data

Returns:

a byte array containing binary data

Since:

1.4

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.

Throws:

IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE

encodeBase64

public static byte[] encodeBase64(byte[] binaryData,
                                  boolean isChunked,
                                  boolean urlSafe)

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

urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters.

Returns:

Base64-encoded data.

Throws:

IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE

Since:

1.4

encodeBase64

public static byte[] encodeBase64(byte[] binaryData,
                                  boolean isChunked,
                                  boolean urlSafe,
                                  int maxResultSize)

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

urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters.

maxResultSize - The maximum result size to accept.

Returns:

Base64-encoded data.

Throws:

IllegalArgumentException - Thrown when the input array needs an output array bigger than maxResultSize

Since:

1.4

decodeBase64

public static byte[] decodeBase64(String base64String)

Decodes a Base64 String into octets

Parameters:

base64String - String containing Base64 data

Returns:

Array containing decoded data.

Since:

1.4

decodeBase64

public static byte[] decodeBase64(byte[] base64Data)

Decodes Base64 data into octets

Parameters:

base64Data - Byte array containing Base64 data

Returns:

Array containing decoded data.

encodeToString

public String encodeToString(byte[] pArray)

Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet.

Parameters:

pArray - a byte array containing binary data

Returns:

A String containing only Base64 character data

Since:

1.4

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

decodeInteger

public static BigInteger decodeInteger(byte[] pArray)

Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature

Parameters:

pArray - a byte array containing base64 character data

Returns:

A BigInteger

Since:

1.4

encodeInteger

public static byte[] encodeInteger(BigInteger bigInt)

Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature

Parameters:

bigInt - a BigInteger

Returns:

A byte array containing base64 character data

Throws:

NullPointerException - if null is passed in

Since:

1.4