org.apache.commons.codec.net
Class QCodec

java.lang.Object
  org.apache.commons.codec.net.RFC1522Codec
      org.apache.commons.codec.net.QCodec

All Implemented Interfaces:

Decoder, Encoder, StringDecoder, StringEncoder

public class QCodec

extends RFC1522Codec

implements StringEncoder, StringDecoder

Similar to the Quoted-Printable content-transfer-encoding defined in RFC 1521 and designed to allow text containing mostly ASCII characters to be decipherable on an ASCII terminal without decoding.

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: QCodec.java,v 1.6 2004/05/24 00:24:32 ggregory Exp $

Author:

Apache Software Foundation

See Also:

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

Field Summary

private static byte	BLANK
private String	charset The default charset used for string decoding and encoding.
private boolean	encodeBlanks
private static BitSet	PRINTABLE_CHARS BitSet of printable characters as defined in RFC 1522.
private static byte	UNDERSCORE

Constructor Summary

QCodec()
Default constructor.

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

Method Summary

Object	decode(Object pObject) Decodes a quoted-printable object into its original form.
String	decode(String pString) Decodes a quoted-printable 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 pObject) Encodes an object into its quoted-printable form using the default charset.
String	encode(String pString) Encodes a string into its quoted-printable form using the default charset.
String	encode(String pString, String charset) Encodes a string into its quoted-printable 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)
boolean	isEncodeBlanks() Tests if optional tranformation of SPACE characters is to be used
void	setEncodeBlanks(boolean b) Defines whether optional tranformation of SPACE characters is to be used

Methods inherited from class java.lang.Object

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

Field Detail

charset

private String charset

The default charset used for string decoding and encoding.

PRINTABLE_CHARS

private static final BitSet PRINTABLE_CHARS

BitSet of printable characters as defined in RFC 1522.

BLANK

private static byte BLANK

UNDERSCORE

private static byte UNDERSCORE

encodeBlanks

private boolean encodeBlanks

Constructor Detail

QCodec

public QCodec()

Default constructor.

QCodec

public QCodec(String charset)

Constructor which allows for the selection of a default charset

Parameters:

charset - the default string charset to use.

See Also:

JRE character encoding names

Method Detail

getEncoding

protected String getEncoding()

Description copied from class: RFC1522Codec

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

Specified by:

getEncoding in class RFC1522Codec

Returns:

name of the codec

doEncoding

protected byte[] doEncoding(byte[] bytes)
                     throws EncoderException

Description copied from class: RFC1522Codec

Encodes an array of bytes using the defined encoding scheme

Specified by:

doEncoding in class RFC1522Codec

Parameters:

bytes - Data to be encoded

Returns:

A byte array containing the encoded data

Throws:

EncoderException - thrown if the Encoder encounters a failure condition during the encoding process.

doDecoding

protected byte[] doDecoding(byte[] bytes)
                     throws DecoderException

Description copied from class: RFC1522Codec

Decodes an array of bytes using the defined encoding scheme

Specified by:

doDecoding in class RFC1522Codec

Parameters:

bytes - Data to be decoded

Returns:

a byte array that contains decoded data

Throws:

DecoderException - A decoder exception is thrown if a Decoder encounters a failure condition during the decode process.

encode

public String encode(String pString,
                     String charset)
              throws EncoderException

Encodes a string into its quoted-printable form using the specified charset. Unsafe characters are escaped.

Parameters:

pString - string to convert to quoted-printable form

charset - the charset for pString

Returns:

quoted-printable string

Throws:

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

encode

public String encode(String pString)
              throws EncoderException

Encodes a string into its quoted-printable form using the default charset. Unsafe characters are escaped.

Specified by:

encode in interface StringEncoder

Parameters:

pString - string to convert to quoted-printable form

Returns:

quoted-printable string

Throws:

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

decode

public String decode(String pString)
              throws DecoderException

Decodes a quoted-printable string into its original form. Escaped characters are converted back to their original representation.

Specified by:

decode in interface StringDecoder

Parameters:

pString - quoted-printable 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 pObject)
              throws EncoderException

Encodes an object into its quoted-printable form using the default charset. Unsafe characters are escaped.

Specified by:

encode in interface Encoder

Parameters:

pObject - object to convert to quoted-printable form

Returns:

quoted-printable object

Throws:

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

decode

public Object decode(Object pObject)
              throws DecoderException

Decodes a quoted-printable object into its original form. Escaped characters are converted back to their original representation.

Specified by:

decode in interface Decoder

Parameters:

pObject - quoted-printable object to convert into its original form

Returns:

original object

Throws:

DecoderException - A decoder exception is 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.

isEncodeBlanks

public boolean isEncodeBlanks()

Tests if optional tranformation of SPACE characters is to be used

Returns:

true if SPACE characters are to be transformed, false otherwise

setEncodeBlanks

public void setEncodeBlanks(boolean b)

Defines whether optional tranformation of SPACE characters is to be used

Parameters:

b - true if SPACE characters are to be transformed, false otherwise

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 RFC1522Codec.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:

JRE character encoding names

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 RFC1522Codec.doEncoding(byte []) method of a concrete class to perform the specific deconding.

Parameters:

text - a string to decode

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