org.apache.james.mime4j.codec

Class EncoderUtil

java.lang.Object

org.apache.james.mime4j.codec.EncoderUtil

public class EncoderUtil
extends java.lang.Object

Static methods for encoding header field values. This includes encoded-words as defined in RFC 2047 or display-names of an e-mail address, for example.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EncoderUtil.Encoding Selects one of the two encodings specified in RFC 2047.
static class	EncoderUtil.Usage Indicates the intended usage of an encoded word.

Field Summary

Fields

Modifier and Type	Field and Description
private static java.util.BitSet	ATEXT_CHARS
private static char	BASE64_PAD
private static byte[]	BASE64_TABLE
private static java.lang.String	ENC_WORD_PREFIX
private static java.lang.String	ENC_WORD_SUFFIX
private static int	ENCODED_WORD_MAX_LENGTH
private static int	MAX_USED_CHARACTERS
private static java.util.BitSet	Q_REGULAR_CHARS
private static java.util.BitSet	Q_RESTRICTED_CHARS
private static java.util.BitSet	TOKEN_CHARS

Constructor Summary

Constructors

Modifier	Constructor and Description
private	EncoderUtil()

Method Summary

Modifier and Type	Method and Description
private static int	bEncodedLength(byte[] bytes)
private static java.nio.charset.Charset	determineCharset(java.lang.String text)
private static EncoderUtil.Encoding	determineEncoding(byte[] bytes, EncoderUtil.Usage usage)
private static byte[]	encode(java.lang.String text, java.nio.charset.Charset charset)
static java.lang.String	encodeAddressDisplayName(java.lang.String displayName) Encodes the display-name portion of an address.
static java.lang.String	encodeAddressLocalPart(java.lang.String localPart) Encodes the local part of an address specification as described in RFC 5322 section 3.4.1.
static java.lang.String	encodeB(byte[] bytes) Encodes the specified byte array using the B encoding defined in RFC 2047.
static void	encodeB(java.io.InputStream in, java.io.OutputStream out) Encodes the given stream using base64.
private static java.lang.String	encodeB(java.lang.String prefix, java.lang.String text, int usedCharacters, java.nio.charset.Charset charset, byte[] bytes)
static java.lang.String	encodeEncodedWord(java.lang.String text, EncoderUtil.Usage usage) Encodes the specified text into an encoded word or a sequence of encoded words separated by space.
static java.lang.String	encodeEncodedWord(java.lang.String text, EncoderUtil.Usage usage, int usedCharacters) Encodes the specified text into an encoded word or a sequence of encoded words separated by space.
static java.lang.String	encodeEncodedWord(java.lang.String text, EncoderUtil.Usage usage, int usedCharacters, java.nio.charset.Charset charset, EncoderUtil.Encoding encoding) Encodes the specified text into an encoded word or a sequence of encoded words separated by space.
static java.lang.String	encodeHeaderParameter(java.lang.String name, java.lang.String value) Encodes the specified strings into a header parameter as described in RFC 2045 section 5.1 and RFC 2183 section 2.
static java.lang.String	encodeIfNecessary(java.lang.String text, EncoderUtil.Usage usage, int usedCharacters) Shortcut method that encodes the specified text into an encoded-word if the text has to be encoded.
static java.lang.String	encodeQ(byte[] bytes, EncoderUtil.Usage usage) Encodes the specified byte array using the Q encoding defined in RFC 2047.
static void	encodeQ(java.io.InputStream in, java.io.OutputStream out) Encodes the given stream using Quoted-Printable.
private static java.lang.String	encodeQ(java.lang.String prefix, java.lang.String text, EncoderUtil.Usage usage, int usedCharacters, java.nio.charset.Charset charset, byte[] bytes)
static void	encodeQBinary(java.io.InputStream in, java.io.OutputStream out) Encodes the given stream using Quoted-Printable.
static boolean	hasToBeEncoded(java.lang.String text, int usedCharacters) Determines if the specified string has to encoded into an encoded-word.
private static char	hexDigit(int i)
private static java.util.BitSet	initChars(java.lang.String specials)
private static boolean	isAtomPhrase(java.lang.String str)
private static boolean	isDotAtomText(java.lang.String str)
static boolean	isToken(java.lang.String str) Tests whether the specified string is a token as defined in RFC 2045 section 5.1.
private static int	qEncodedLength(byte[] bytes, EncoderUtil.Usage usage)
private static java.lang.String	quote(java.lang.String str)

Methods inherited from class java.lang.Object

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

Field Detail

BASE64_TABLE

private static final byte[] BASE64_TABLE

BASE64_PAD

private static final char BASE64_PAD

See Also:

Constant Field Values

Q_REGULAR_CHARS

private static final java.util.BitSet Q_REGULAR_CHARS

Q_RESTRICTED_CHARS

private static final java.util.BitSet Q_RESTRICTED_CHARS

MAX_USED_CHARACTERS

private static final int MAX_USED_CHARACTERS

See Also:

Constant Field Values

ENC_WORD_PREFIX

private static final java.lang.String ENC_WORD_PREFIX

See Also:

Constant Field Values

ENC_WORD_SUFFIX

private static final java.lang.String ENC_WORD_SUFFIX

See Also:

Constant Field Values

ENCODED_WORD_MAX_LENGTH

private static final int ENCODED_WORD_MAX_LENGTH

See Also:

Constant Field Values

TOKEN_CHARS

private static final java.util.BitSet TOKEN_CHARS

ATEXT_CHARS

private static final java.util.BitSet ATEXT_CHARS

Constructor Detail

EncoderUtil

private EncoderUtil()

Method Detail

initChars

private static java.util.BitSet initChars(java.lang.String specials)

encodeAddressDisplayName

public static java.lang.String encodeAddressDisplayName(java.lang.String displayName)

Encodes the display-name portion of an address. See RFC 5322 section 3.4 and RFC 2047 section 5.3. The specified string should not be folded.

Parameters:

displayName - display-name to encode.

Returns:

encoded display-name.

encodeAddressLocalPart

public static java.lang.String encodeAddressLocalPart(java.lang.String localPart)

Encodes the local part of an address specification as described in RFC 5322 section 3.4.1. Leading and trailing CFWS should have been removed before calling this method. The specified string should not contain any illegal (control or non-ASCII) characters.

Parameters:

localPart - the local part to encode

Returns:

the encoded local part.

encodeHeaderParameter

public static java.lang.String encodeHeaderParameter(java.lang.String name,
                                                     java.lang.String value)

Encodes the specified strings into a header parameter as described in RFC 2045 section 5.1 and RFC 2183 section 2. The specified strings should not contain any illegal (control or non-ASCII) characters.

Parameters:

name - parameter name.

value - parameter value.

Returns:

encoded result.

encodeIfNecessary

public static java.lang.String encodeIfNecessary(java.lang.String text,
                                                 EncoderUtil.Usage usage,
                                                 int usedCharacters)

Shortcut method that encodes the specified text into an encoded-word if the text has to be encoded.

Parameters:

text - text to encode.

usage - whether the encoded-word is to be used to replace a text token or a word entity (see RFC 822).

usedCharacters - number of characters already used up (0 <= usedCharacters <= 50).

Returns:

the specified text if encoding is not necessary or an encoded word or a sequence of encoded words otherwise.

hasToBeEncoded

public static boolean hasToBeEncoded(java.lang.String text,
                                     int usedCharacters)

Determines if the specified string has to encoded into an encoded-word. Returns true if the text contains characters that don't fall into the printable ASCII character set or if the text contains a 'word' (sequence of non-whitespace characters) longer than 77 characters (including characters already used up in the line).

Parameters:

text - text to analyze.

usedCharacters - number of characters already used up (0 <= usedCharacters <= 50).

Returns:

true if the specified text has to be encoded into an encoded-word, false otherwise.

encodeEncodedWord

public static java.lang.String encodeEncodedWord(java.lang.String text,
                                                 EncoderUtil.Usage usage)

Encodes the specified text into an encoded word or a sequence of encoded words separated by space. The text is separated into a sequence of encoded words if it does not fit in a single one.

The charset to encode the specified text into a byte array and the encoding to use for the encoded-word are detected automatically.

This method assumes that zero characters have already been used up in the current line.

Parameters:

text - text to encode.

usage - whether the encoded-word is to be used to replace a text token or a word entity (see RFC 822).

Returns:

the encoded word (or sequence of encoded words if the given text does not fit in a single encoded word).

See Also:

hasToBeEncoded(String, int)

encodeEncodedWord

public static java.lang.String encodeEncodedWord(java.lang.String text,
                                                 EncoderUtil.Usage usage,
                                                 int usedCharacters)

Encodes the specified text into an encoded word or a sequence of encoded words separated by space. The text is separated into a sequence of encoded words if it does not fit in a single one.

The charset to encode the specified text into a byte array and the encoding to use for the encoded-word are detected automatically.

Parameters:

text - text to encode.

usage - whether the encoded-word is to be used to replace a text token or a word entity (see RFC 822).

usedCharacters - number of characters already used up (0 <= usedCharacters <= 50).

Returns:

the encoded word (or sequence of encoded words if the given text does not fit in a single encoded word).

See Also:

hasToBeEncoded(String, int)

encodeEncodedWord

public static java.lang.String encodeEncodedWord(java.lang.String text,
                                                 EncoderUtil.Usage usage,
                                                 int usedCharacters,
                                                 java.nio.charset.Charset charset,
                                                 EncoderUtil.Encoding encoding)

Encodes the specified text into an encoded word or a sequence of encoded words separated by space. The text is separated into a sequence of encoded words if it does not fit in a single one.

Parameters:

text - text to encode.

usage - whether the encoded-word is to be used to replace a text token or a word entity (see RFC 822).

usedCharacters - number of characters already used up (0 <= usedCharacters <= 50).

charset - the Java charset that should be used to encode the specified string into a byte array. A suitable charset is detected automatically if this parameter is null.

encoding - the encoding to use for the encoded-word (either B or Q). A suitable encoding is automatically chosen if this parameter is null.

Returns:

the encoded word (or sequence of encoded words if the given text does not fit in a single encoded word).

See Also:

hasToBeEncoded(String, int)

encodeB

public static java.lang.String encodeB(byte[] bytes)

Encodes the specified byte array using the B encoding defined in RFC 2047.

Parameters:

bytes - byte array to encode.

Returns:

encoded string.

encodeQ

public static java.lang.String encodeQ(byte[] bytes,
                                       EncoderUtil.Usage usage)

Encodes the specified byte array using the Q encoding defined in RFC 2047.

Parameters:

bytes - byte array to encode.

usage - whether the encoded-word is to be used to replace a text token or a word entity (see RFC 822).

Returns:

encoded string.

encodeQBinary

public static void encodeQBinary(java.io.InputStream in,
                                 java.io.OutputStream out)
                          throws java.io.IOException

Encodes the given stream using Quoted-Printable. This assumes that stream is binary and therefore escapes all line endings.

Parameters:

in - not null

out - not null

Throws:

java.io.IOException

encodeQ

public static void encodeQ(java.io.InputStream in,
                           java.io.OutputStream out)
                    throws java.io.IOException

Encodes the given stream using Quoted-Printable. This assumes that stream is text and therefore does not escape all line endings.

Parameters:

in - not null

out - not null

Throws:

java.io.IOException

encodeB

public static void encodeB(java.io.InputStream in,
                           java.io.OutputStream out)
                    throws java.io.IOException

Encodes the given stream using base64.

Parameters:

in - not null

out - not null

Throws:

java.io.IOException - if an I/O error occurs

isToken

public static boolean isToken(java.lang.String str)

Tests whether the specified string is a token as defined in RFC 2045 section 5.1.

Parameters:

str - string to test.

Returns:

true if the specified string is a RFC 2045 token, false otherwise.

isAtomPhrase

private static boolean isAtomPhrase(java.lang.String str)

isDotAtomText

private static boolean isDotAtomText(java.lang.String str)

quote

private static java.lang.String quote(java.lang.String str)

encodeB

private static java.lang.String encodeB(java.lang.String prefix,
                                        java.lang.String text,
                                        int usedCharacters,
                                        java.nio.charset.Charset charset,
                                        byte[] bytes)

bEncodedLength

private static int bEncodedLength(byte[] bytes)

encodeQ

private static java.lang.String encodeQ(java.lang.String prefix,
                                        java.lang.String text,
                                        EncoderUtil.Usage usage,
                                        int usedCharacters,
                                        java.nio.charset.Charset charset,
                                        byte[] bytes)

qEncodedLength

private static int qEncodedLength(byte[] bytes,
                                  EncoderUtil.Usage usage)

encode

private static byte[] encode(java.lang.String text,
                             java.nio.charset.Charset charset)

determineCharset

private static java.nio.charset.Charset determineCharset(java.lang.String text)

determineEncoding

private static EncoderUtil.Encoding determineEncoding(byte[] bytes,
                                                      EncoderUtil.Usage usage)

hexDigit

private static char hexDigit(int i)