org.apache.commons.codec.net

Class QCodec

java.lang.Object

org.apache.commons.codec.net.QCodec

All Implemented Interfaces:

Decoder, Encoder, StringDecoder, StringEncoder

public class QCodec
extends Object
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.

This class is conditionally thread-safe. The instance field encodeBlanks is mutable setEncodeBlanks(boolean) but is not volatile, and accesses are not synchronised. If an instance of the class is shared between threads, the caller needs to ensure that suitable synchronisation is used to ensure safe publication of the value between threads, and must not invoke setEncodeBlanks(boolean) after initial setup.

Since:

1.3

Version:

$Id: QCodec.java 1429868 2013-01-07 16:08:05Z ggregory $

See Also:

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

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
QCodec() Default constructor.
QCodec(Charset charset) Constructor which allows for the selection of a default charset.
QCodec(String charsetName) Constructor which allows for the selection of a default charset.

Method Summary

Methods

Modifier and Type	Method and Description
Object	decode(Object obj) Decodes a quoted-printable object into its original form.
String	decode(String str) 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 obj) Encodes an object into its quoted-printable form using the default charset.
String	encode(String str) Encodes a string into its quoted-printable form using the default charset.
String	encode(String str, Charset charset) Encodes a string into its quoted-printable form using the specified charset.
String	encode(String str, String charset) Encodes a string into its quoted-printable form using the specified charset.
protected String	encodeText(String text, Charset charset) Applies an RFC 1522 compliant encoding scheme to the given string of text with the given charset.
protected String	encodeText(String text, String charsetName) Applies an RFC 1522 compliant encoding scheme to the given string of text with the given charset.
Charset	getCharset() Gets the default charset name used for string decoding and encoding.
String	getDefaultCharset() Gets the default charset name 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 transformation of SPACE characters is to be used
void	setEncodeBlanks(boolean b) Defines whether optional transformation 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

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

QCodec

public QCodec()

Default constructor.

QCodec

public QCodec(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

QCodec

public QCodec(String charsetName)

Constructor which allows for the selection of a default charset.

Parameters:

charsetName - the charset to use.

Throws:

UnsupportedCharsetException - If the named charset is unavailable

Since:

1.7 throws UnsupportedCharsetException if the named charset is unavailable

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)
                     throws DecoderException

Decodes an array of bytes using the defined encoding scheme.

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 str,
            Charset charset)
              throws EncoderException

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

Parameters:

str - string to convert to quoted-printable form

charset - the charset for str

Returns:

quoted-printable string

Throws:

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

Since:

1.7

encode

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

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

Parameters:

str - string to convert to quoted-printable form

charset - the charset for str

Returns:

quoted-printable string

Throws:

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

encode

public String encode(String str)
              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:

str - 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 str)
              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:

str - 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 obj)
              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:

obj - 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 obj)
              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:

obj - quoted-printable 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 Charset getCharset()

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

Returns:

the default charset name

Since:

1.7

getDefaultCharset

public String getDefaultCharset()

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

Returns:

the default charset name

isEncodeBlanks

public boolean isEncodeBlanks()

Tests if optional transformation 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 transformation 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,
                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 String encodeText(String text,
                String charsetName)
                     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 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.

UnsupportedEncodingException - if charset is not available

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 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.

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