net.pwall.util

Class Base64

java.lang.Object

net.pwall.util.Base64

public class Base64
extends Object

Encode and decode Base64. This functionality exists in a variety of other libraries, but those libraries generally include a lot of other unneeded code.

Author:

Peter Wall

Method Summary

Modifier and Type	Method and Description
static void	appendEncoded(Appendable app, byte[] data) Append a byte array to an Appendable as Base64-encoded characters.
static void	appendEncoded(Appendable app, byte[] data, int start, int end) Append a section of a byte array to an Appendable as Base64-encoded characters.
static void	appendURLEncoded(Appendable app, byte[] data) Append a byte array to an Appendable as Base64-encoded characters, using the URL variant of Base64.
static void	appendURLEncoded(Appendable app, byte[] data, int start, int end) Append a section of a byte array to an Appendable as Base64-encoded characters, using the URL variant of Base64.
static byte[]	decode(byte[] data) Decode a byte array from Base64.
static byte[]	decode(CharSequence data) Decode a CharSequence (String, StringBuilder etc.) from Base64.
static byte[]	encode(byte[] data) Encode a byte array into Base64, returning another byte array.
String	encodeString(byte[] data) Encode a byte array into Base64, returning a string.
String	encodeStringURL(byte[] data) Encode a byte array into the URL variant of Base64, returning a string.
static byte[]	encodeURL(byte[] data) Encode a byte array into the URL variant of Base64, returning another byte array.
static int	getEncodedLength(int n) Get the encoded length of data encoded into Base64.
static int	getEncodedURLLength(int n) Get the encoded length of data encoded into the URL variant of Base64.

Methods inherited from class java.lang.Object

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

Method Detail

getEncodedLength

public static int getEncodedLength(int n)

Get the encoded length of data encoded into Base64.

Parameters:

n - the source data length

Returns:

the encoded data length

Throws:

NullPointerException - if the data is null

getEncodedURLLength

public static int getEncodedURLLength(int n)

Get the encoded length of data encoded into the URL variant of Base64. This variant uses different characters for the last two positions in the encoding table, and (significantly for length calculation) it doesn't pad with equal signs.

Parameters:

n - the source data length

Returns:

the encoded data length

Throws:

NullPointerException - if the data is null

encode

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

Encode a byte array into Base64, returning another byte array.

Parameters:

data - the source data

Returns:

the encoded data

Throws:

NullPointerException - if the data is null

encodeURL

public static byte[] encodeURL(byte[] data)

Encode a byte array into the URL variant of Base64, returning another byte array. The URL variant uses different characters for the last two positions in the encoding table, and it doesn't pad with equal signs.

Parameters:

data - the source data

Returns:

the encoded data

Throws:

NullPointerException - if the data is null

appendEncoded

public static void appendEncoded(Appendable app,
                                 byte[] data)
                          throws IOException

Append a byte array to an Appendable as Base64-encoded characters.

Parameters:

app - the Appendable

data - the source data

Throws:

IOException - if thrown by the Appendable

NullPointerException - if the data is null

appendEncoded

public static void appendEncoded(Appendable app,
                                 byte[] data,
                                 int start,
                                 int end)
                          throws IOException

Append a section of a byte array to an Appendable as Base64-encoded characters.

Parameters:

app - the Appendable

data - the source data

start - the start index of the data to be encoded

end - the end index

Throws:

IOException - if thrown by the Appendable

NullPointerException - if the data is null

appendURLEncoded

public static void appendURLEncoded(Appendable app,
                                    byte[] data)
                             throws IOException

Append a byte array to an Appendable as Base64-encoded characters, using the URL variant of Base64.

Parameters:

app - the Appendable

data - the source data

Throws:

IOException - if thrown by the Appendable

NullPointerException - if the data is null

appendURLEncoded

public static void appendURLEncoded(Appendable app,
                                    byte[] data,
                                    int start,
                                    int end)
                             throws IOException

Append a section of a byte array to an Appendable as Base64-encoded characters, using the URL variant of Base64.

Parameters:

app - the Appendable

data - the source data

start - the start index of the data to be encoded

end - the end index

Throws:

IOException - if thrown by the Appendable

NullPointerException - if the data is null

encodeString

public String encodeString(byte[] data)

Encode a byte array into Base64, returning a string.

Parameters:

data - the source data

Returns:

the encoded string

Throws:

NullPointerException - if the data is null

encodeStringURL

public String encodeStringURL(byte[] data)

Encode a byte array into the URL variant of Base64, returning a string. The URL variant uses different characters for the last two positions in the encoding table, and it doesn't pad with equal signs.

Parameters:

data - the source data

Returns:

the encoded data

Throws:

NullPointerException - if the data is null

decode

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

Decode a byte array from Base64. Both the original and the URL variants are handled.

Parameters:

data - the source data

Returns:

the decoded data

Throws:

IllegalArgumentException - if the data is not valid Base64

NullPointerException - if the data is null

decode

public static byte[] decode(CharSequence data)

Decode a CharSequence (String, StringBuilder etc.) from Base64. Both the original and the URL variants are handled.

Parameters:

data - the source data

Returns:

the decoded data

Throws:

IllegalArgumentException - if the data is not valid Base64

NullPointerException - if the data is null