程序包 java.util

类 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.

从以下版本开始:

1.8

嵌套类概要

嵌套类

限定符和类型	类	说明
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.

方法概要

限定符和类型	方法	说明
static Base64.Decoder	getDecoder()	Returns a Decoder that decodes using the Basic type base64 encoding scheme.
static Base64.Encoder	getEncoder()	Returns a Encoder that encodes using the Basic type base64 encoding scheme.
static Base64.Decoder	getMimeDecoder()	Returns a Decoder that decodes using the MIME type base64 decoding scheme.
static Base64.Encoder	getMimeEncoder()	Returns a Encoder that encodes using the MIME type base64 encoding scheme.
static Base64.Encoder	getMimeEncoder(int lineLength, byte[] lineSeparator)	Returns a Encoder that encodes using the MIME type base64 encoding scheme with specified line length and line separators.
static Base64.Decoder	getUrlDecoder()	Returns a Decoder that decodes using the URL and Filename safe type base64 encoding scheme.
static Base64.Encoder	getUrlEncoder()	Returns a Encoder that encodes using the URL and Filename safe type base64 encoding scheme.

从类继承的方法 java.lang.Object

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

方法详细资料

getEncoder

public static Base64.Encoder getEncoder()

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

返回:

A Base64 encoder.

getUrlEncoder

public static Base64.Encoder getUrlEncoder()

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

返回:

A Base64 encoder.

getMimeEncoder

public static Base64.Encoder getMimeEncoder()

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

返回:

A Base64 encoder.

getMimeEncoder

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

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

参数:

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

返回:

A Base64 encoder.

抛出:

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

getDecoder

public static Base64.Decoder getDecoder()

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

返回:

A Base64 decoder.

getUrlDecoder

public static Base64.Decoder getUrlDecoder()

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

返回:

A Base64 decoder.

getMimeDecoder

public static Base64.Decoder getMimeDecoder()

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

返回:

A Base64 decoder.