Package org.apache.commons.codec.net

Class BCodec

java.lang.Object

org.apache.commons.codec.net.BCodec

All Implemented Interfaces:

Decoder, Encoder, StringDecoder, StringEncoder

public class BCodec
extends java.lang.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.

This class is immutable and thread-safe.

Since:

1.3

See Also:

MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text

Field Summary

Fields

Modifier and Type	Field	Description
protected static java.lang.String	POSTFIX	Prefix.
protected static java.lang.String	PREFIX	Postfix.
protected static char	SEP	Separator.

Constructor Summary

Constructors

Constructor	Description
BCodec()	Default constructor.
BCodec(java.lang.String charsetName)	Constructor which allows for the selection of a default Charset
BCodec(java.nio.charset.Charset charset)	Constructor which allows for the selection of a default Charset
BCodec(java.nio.charset.Charset charset, CodecPolicy decodingPolicy)	Constructor which allows for the selection of a default Charset.

Method Summary

Modifier and Type	Method	Description
java.lang.Object	decode(java.lang.Object value)	Decodes a Base64 object into its original form.
java.lang.String	decode(java.lang.String value)	Decodes a Base64 string into its original form.
protected java.lang.String	decodeText(java.lang.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.
java.lang.Object	encode(java.lang.Object value)	Encodes an object into its Base64 form using the default Charset.
java.lang.String	encode(java.lang.String strSource)	Encodes a string into its Base64 form using the default Charset.
java.lang.String	encode(java.lang.String strSource, java.lang.String sourceCharset)	Encodes a string into its Base64 form using the specified Charset.
java.lang.String	encode(java.lang.String strSource, java.nio.charset.Charset sourceCharset)	Encodes a string into its Base64 form using the specified Charset.
protected java.lang.String	encodeText(java.lang.String text, java.lang.String charsetName)	Applies an RFC 1522 compliant encoding scheme to the given string of text with the given charset.
protected java.lang.String	encodeText(java.lang.String text, java.nio.charset.Charset charset)	Applies an RFC 1522 compliant encoding scheme to the given string of text with the given charset.
java.nio.charset.Charset	getCharset()	Gets the default Charset name used for string decoding and encoding.
java.lang.String	getDefaultCharset()	Gets the default Charset name used for string decoding and encoding.
protected java.lang.String	getEncoding()	Returns the codec name (referred to as encoding in the RFC 1522).
boolean	isStrictDecoding()	Returns true if decoding behavior is strict.

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 java.lang.String POSTFIX

Prefix.

See Also:

Constant Field Values

PREFIX

protected static final java.lang.String PREFIX

Postfix.

See Also:

Constant Field Values

Constructor Detail

BCodec

public BCodec()

Default constructor.

BCodec

public BCodec(java.nio.charset.Charset charset)

Constructor which allows for the selection of a default Charset

Parameters:

charset - the default string Charset to use.

Since:

1.7

See Also:

Standard charsets

BCodec

public BCodec(java.nio.charset.Charset charset,
              CodecPolicy decodingPolicy)

Constructor which allows for the selection of a default Charset.

Parameters:

charset - the default string Charset to use.

decodingPolicy - The decoding policy.

Since:

1.15

See Also:

Standard charsets

BCodec

public BCodec(java.lang.String charsetName)

Constructor which allows for the selection of a default Charset

Parameters:

charsetName - the default Charset to use.

Throws:

java.nio.charset.UnsupportedCharsetException - If the named Charset is unavailable

Since:

1.7 throws UnsupportedCharsetException if the named Charset is unavailable

See Also:

Standard charsets

Method Detail

isStrictDecoding

public boolean isStrictDecoding()

Returns true if decoding behavior is strict. Decoding will raise a DecoderException if trailing bits are not part of a valid Base64 encoding.

The default is false for lenient encoding. Decoding will compose trailing bits into 8-bit bytes and discard the remainder.

Returns:

true if using strict decoding

Since:

1.15

getEncoding

protected java.lang.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 java.lang.String encode(java.lang.String strSource,
                               java.nio.charset.Charset sourceCharset)
                        throws EncoderException

Encodes a string into its Base64 form using the specified Charset. Unsafe characters are escaped.

Parameters:

strSource - string to convert to Base64 form

sourceCharset - the Charset for value

Returns:

Base64 string

Throws:

EncoderException - thrown if a failure condition is encountered during the encoding process.

Since:

1.7

encode

public java.lang.String encode(java.lang.String strSource,
                               java.lang.String sourceCharset)
                        throws EncoderException

Encodes a string into its Base64 form using the specified Charset. Unsafe characters are escaped.

Parameters:

strSource - string to convert to Base64 form

sourceCharset - the Charset for value

Returns:

Base64 string

Throws:

EncoderException - thrown if a failure condition is encountered during the encoding process.

encode

public java.lang.String encode(java.lang.String strSource)
                        throws EncoderException

Encodes a string into its Base64 form using the default Charset. Unsafe characters are escaped.

Specified by:

encode in interface StringEncoder

Parameters:

strSource - string to convert to Base64 form

Returns:

Base64 string

Throws:

EncoderException - thrown if a failure condition is encountered during the encoding process.

decode

public java.lang.String decode(java.lang.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 java.lang.Object encode(java.lang.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 java.lang.Object decode(java.lang.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.

getCharset

public java.nio.charset.Charset getCharset()

Gets the default Charset name used for string decoding and encoding.

Returns:

the default Charset name

Since:

1.7

getDefaultCharset

public java.lang.String getDefaultCharset()

Gets the default Charset name used for string decoding and encoding.

Returns:

the default Charset name

encodeText

protected java.lang.String encodeText(java.lang.String text,
                                      java.nio.charset.Charset charset)
                               throws EncoderException

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 encoding.

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 condition during the Encoding process.

See Also:

Standard charsets

encodeText

protected java.lang.String encodeText(java.lang.String text,
                                      java.lang.String charsetName)
                               throws EncoderException,
                                      java.io.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 encoding.

Parameters:

text - a string to encode

charsetName - the charset to use

Returns:

RFC 1522 compliant "encoded-word"

Throws:

EncoderException - thrown if there is an error condition during the Encoding process.

java.io.UnsupportedEncodingException - if charset is not available

See Also:

Standard charsets

decodeText

protected java.lang.String decodeText(java.lang.String text)
                               throws DecoderException,
                                      java.io.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 decoding.

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 condition during the decoding process.

java.io.UnsupportedEncodingException - thrown if charset specified in the "encoded-word" header is not supported