org.apache.commons.codec.net
Class BCodec

java.lang.Object
  extended by org.apache.commons.codec.net.BCodec
All Implemented Interfaces:
Decoder, Encoder, StringDecoder, StringEncoder

public class BCodec
extends Object
implements StringEncoder, StringDecoder

Identical to the Base64 encoding defined by RFC 1521 and allows a character set to be specified.

RFC 1522 describes techniques to allow the encoding of non-ASCII text in various portions of a RFC 822 [2] message header, in a manner which is unlikely to confuse existing message handling software.

Since:
1.3
Version:
$Id: BCodec.java 797857 2009-07-25 23:43:33Z ggregory $
Author:
Apache Software Foundation
See Also:
MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text

Field Summary
protected static String POSTFIX
          Prefix
protected static String PREFIX
          Postfix
protected static char SEP
          Separator.
 
Constructor Summary
BCodec()
          Default constructor.
BCodec(String charset)
          Constructor which allows for the selection of a default charset
 
Method Summary
 Object decode(Object value)
          Decodes a Base64 object into its original form.
 String decode(String value)
          Decodes a Base64 string into its original form.
protected  String decodeText(String text)
          Applies an RFC 1522 compliant decoding scheme to the given string of text.
protected  byte[] doDecoding(byte[] bytes)
          Decodes an array of bytes using the defined encoding scheme
protected  byte[] doEncoding(byte[] bytes)
          Encodes an array of bytes using the defined encoding scheme
 Object encode(Object value)
          Encodes an object into its Base64 form using the default charset.
 String encode(String value)
          Encodes a string into its Base64 form using the default charset.
 String encode(String value, String charset)
          Encodes a string into its Base64 form using the specified charset.
protected  String encodeText(String text, String charset)
          Applies an RFC 1522 compliant encoding scheme to the given string of text with the given charset.
 String getDefaultCharset()
          The default charset used for string decoding and encoding.
protected  String getEncoding()
          Returns the codec name (referred to as encoding in the RFC 1522)
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

SEP

protected static final char SEP
Separator.

See Also:
Constant Field Values

POSTFIX

protected static final String POSTFIX
Prefix

See Also:
Constant Field Values

PREFIX

protected static final String PREFIX
Postfix

See Also:
Constant Field Values
Constructor Detail

BCodec

public BCodec()
Default constructor.


BCodec

public BCodec(String charset)
Constructor which allows for the selection of a default charset

Parameters:
charset - the default string charset to use.
See Also:
Standard charsets
Method Detail

getEncoding

protected String getEncoding()
Returns the codec name (referred to as encoding in the RFC 1522)

Returns:
name of the codec

doEncoding

protected byte[] doEncoding(byte[] bytes)
Encodes an array of bytes using the defined encoding scheme

Parameters:
bytes - Data to be encoded
Returns:
A byte array containing the encoded data

doDecoding

protected byte[] doDecoding(byte[] bytes)
Decodes an array of bytes using the defined encoding scheme

Parameters:
bytes - Data to be decoded
Returns:
a byte array that contains decoded data

encode

public String encode(String value,
                     String charset)
              throws EncoderException
Encodes a string into its Base64 form using the specified charset. Unsafe characters are escaped.

Parameters:
value - string to convert to Base64 form
charset - the charset for value
Returns:
Base64 string
Throws:
EncoderException - thrown if a failure condition is encountered during the encoding process.

encode

public String encode(String value)
              throws EncoderException
Encodes a string into its Base64 form using the default charset. Unsafe characters are escaped.

Specified by:
encode in interface StringEncoder
Parameters:
value - string to convert to Base64 form
Returns:
Base64 string
Throws:
EncoderException - thrown if a failure condition is encountered during the encoding process.

decode

public String decode(String value)
              throws DecoderException
Decodes a Base64 string into its original form. Escaped characters are converted back to their original representation.

Specified by:
decode in interface StringDecoder
Parameters:
value - Base64 string to convert into its original form
Returns:
original string
Throws:
DecoderException - A decoder exception is thrown if a failure condition is encountered during the decode process.

encode

public Object encode(Object value)
              throws EncoderException
Encodes an object into its Base64 form using the default charset. Unsafe characters are escaped.

Specified by:
encode in interface Encoder
Parameters:
value - object to convert to Base64 form
Returns:
Base64 object
Throws:
EncoderException - thrown if a failure condition is encountered during the encoding process.

decode

public Object decode(Object value)
              throws DecoderException
Decodes a Base64 object into its original form. Escaped characters are converted back to their original representation.

Specified by:
decode in interface Decoder
Parameters:
value - Base64 object to convert into its original form
Returns:
original object
Throws:
DecoderException - Thrown if the argument is not a String. Thrown if a failure condition is encountered during the decode process.

getDefaultCharset

public String getDefaultCharset()
The default charset used for string decoding and encoding.

Returns:
the default string charset.

encodeText

protected String encodeText(String text,
                            String charset)
                     throws EncoderException,
                            UnsupportedEncodingException
Applies an RFC 1522 compliant encoding scheme to the given string of text with the given charset. This method constructs the "encoded-word" header common to all the RFC 1522 codecs and then invokes doEncoding(byte []) method of a concrete class to perform the specific enconding.

Parameters:
text - a string to encode
charset - a charset to be used
Returns:
RFC 1522 compliant "encoded-word"
Throws:
EncoderException - thrown if there is an error conidition during the Encoding process.
UnsupportedEncodingException - thrown if charset is not supported
See Also:
Standard charsets

decodeText

protected String decodeText(String text)
                     throws DecoderException,
                            UnsupportedEncodingException
Applies an RFC 1522 compliant decoding scheme to the given string of text. This method processes the "encoded-word" header common to all the RFC 1522 codecs and then invokes doEncoding(byte []) method of a concrete class to perform the specific deconding.

Parameters:
text - a string to decode
Returns:
A new decoded String or null if the input is null.
Throws:
DecoderException - thrown if there is an error conidition during the Decoding process.
UnsupportedEncodingException - thrown if charset specified in the "encoded-word" header is not supported


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