java.util

Class Base64

java.lang.Object

java.util.Base64

public class Base64
extends Object

This class consists exclusively of static methods for obtaining encoders and decoders for the Base64 encoding scheme. The implementation of this class supports the following types of Base64 as specified in RFC 4648 and RFC 2045.

• Basic

  Uses "The Base64 Alphabet" as specified in Table 1 of RFC 4648 and RFC 2045 for encoding and decoding operation. The encoder does not add any line feed (line separator) character. The decoder rejects data that contains characters outside the base64 alphabet.

• URL and Filename safe

  Uses the "URL and Filename safe Base64 Alphabet" as specified in Table 2 of RFC 4648 for encoding and decoding. The encoder does not add any line feed (line separator) character. The decoder rejects data that contains characters outside the base64 alphabet.

• MIME

  Uses the "The Base64 Alphabet" as specified in Table 1 of RFC 2045 for encoding and decoding operation. The encoded output must be represented in lines of no more than 76 characters each and uses a carriage return '\r' followed immediately by a linefeed '\n' as the line separator. No line separator is added to the end of the encoded output. All line separators or other characters not found in the base64 alphabet table are ignored in decoding operation.

Unless otherwise noted, passing a null argument to a method of this class will cause a NullPointerException to be thrown.

Since:

1.8

Author:

Xueming Shen

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Base64.Decoder This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.
static class	Base64.Encoder This class implements an encoder for encoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.

Method Summary

Modifier and Type	Method and Description
static Base64.Decoder	getDecoder() Returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme.
static Base64.Encoder	getEncoder() Returns a Base64.Encoder that encodes using the Basic type base64 encoding scheme.
static Base64.Decoder	getMimeDecoder() Returns a Base64.Decoder that decodes using the MIME type base64 decoding scheme.
static Base64.Encoder	getMimeEncoder() Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme.
static Base64.Encoder	getMimeEncoder(int lineLength, byte[] lineSeparator) Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme with specified line length and line separators.
static Base64.Decoder	getUrlDecoder() Returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme.
static Base64.Encoder	getUrlEncoder() Returns a Base64.Encoder that encodes using the URL and Filename safe type base64 encoding scheme.

Methods inherited from class java.lang.Object

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

Method Detail

getDecoder

public static Base64.Decoder getDecoder()

Returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme.

Returns:

A Base64 decoder.

getEncoder

public static Base64.Encoder getEncoder()

Returns a Base64.Encoder that encodes using the Basic type base64 encoding scheme.

Returns:

A Base64 encoder.

getMimeDecoder

public static Base64.Decoder getMimeDecoder()

Returns a Base64.Decoder that decodes using the MIME type base64 decoding scheme.

Returns:

A Base64 decoder.

getMimeEncoder

public static Base64.Encoder getMimeEncoder()

Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme.

Returns:

A Base64 encoder.

getMimeEncoder

public static Base64.Encoder getMimeEncoder(int lineLength,
                                            byte[] lineSeparator)

Returns a Base64.Encoder that encodes using the MIME type base64 encoding scheme with specified line length and line separators.

Parameters:

lineLength - the length of each output line (rounded down to nearest multiple of 4). If lineLength <= 0 the output will not be separated in lines

lineSeparator - the line separator for each output line

Returns:

A Base64 encoder.

Throws:

IllegalArgumentException - if lineSeparator includes any character of "The Base64 Alphabet" as specified in Table 1 of RFC 2045.

getUrlDecoder

public static Base64.Decoder getUrlDecoder()

Returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme.

Returns:

A Base64 decoder.

getUrlEncoder

public static Base64.Encoder getUrlEncoder()

Returns a Base64.Encoder that encodes using the URL and Filename safe type base64 encoding scheme.

Returns:

A Base64 encoder.