Class EncoderUtil

java.lang.Object
org.apache.james.mime4j.codec.EncoderUtil
public class EncoderUtil extends 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.

  • Field Details

    • BASE64_TABLE

      private static final byte[] BASE64_TABLE

    • BASE64_PAD

      private static final char BASE64_PAD
      See Also:

    • Q_REGULAR_CHARS

      private static final BitSet Q_REGULAR_CHARS

    • Q_RESTRICTED_CHARS

      private static final BitSet Q_RESTRICTED_CHARS

    • MAX_USED_CHARACTERS

      private static final int MAX_USED_CHARACTERS
      See Also:

    • ENC_WORD_PREFIX

      private static final String ENC_WORD_PREFIX
      See Also:

    • ENC_WORD_SUFFIX

      private static final String ENC_WORD_SUFFIX
      See Also:

    • ENCODED_WORD_MAX_LENGTH

      private static final int ENCODED_WORD_MAX_LENGTH
      See Also:

    • TOKEN_CHARS

      private static final BitSet TOKEN_CHARS

    • ATEXT_CHARS

      private static final BitSet ATEXT_CHARS

    • QUOTE

      private static final Pattern QUOTE

  • Constructor Details

    • EncoderUtil

      private EncoderUtil()

  • Method Details

    • initChars

      private static BitSet initChars(String specials)

    • encodeAddressDisplayName

      public static String encodeAddressDisplayName(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 String encodeAddressLocalPart(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 String encodeHeaderParameter(String name, 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 String encodeIfNecessary(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(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 String encodeEncodedWord(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:

    • encodeEncodedWord

      public static String encodeEncodedWord(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:

    • encodeEncodedWord

      public static String encodeEncodedWord(String text, EncoderUtil.Usage usage, int usedCharacters, 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:

    • encodeB

      public static 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 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(InputStream in, OutputStream out) throws 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:
      IOException

    • encodeQ

      public static void encodeQ(InputStream in, OutputStream out) throws 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:
      IOException

    • encodeB

      public static void encodeB(InputStream in, OutputStream out) throws IOException
      Encodes the given stream using base64.
      Parameters:
      in - not null
      out - not null
      Throws:
      IOException - if an I/O error occurs

    • isToken

      public static boolean isToken(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(String str)

    • isDotAtomText

      private static boolean isDotAtomText(String str)

    • quote

      private static String quote(String str)

    • encodeB

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

    • bEncodedLength

      private static int bEncodedLength(byte[] bytes)

    • encodeQ

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

    • qEncodedLength

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

    • encode

      private static byte[] encode(String text, Charset charset)

    • determineCharset

      private static Charset determineCharset(String text)

    • determineEncoding

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

    • hexDigit

      private static char hexDigit(int i)