Class BaseNCodec

Field Detail

• MIME_CHUNK_SIZE

  public static final int MIME_CHUNK_SIZE

  MIME chunk size per RFC 2045 section 6.8.

  The 76 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.

  See Also:

  RFC 2045 section 6.8, Constant Field Values

• PEM_CHUNK_SIZE

  public static final int PEM_CHUNK_SIZE

  PEM chunk size per RFC 1421 section 4.3.2.4.

  The 64 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.

  See Also:

  RFC 1421 section 4.3.2.4, Constant Field Values

• MASK_8BITS

  protected static final int MASK_8BITS

  Mask used to extract 8 bits, used in decoding bytes

  See Also:

  Constant Field Values

• PAD_DEFAULT

  protected static final byte PAD_DEFAULT

  Byte used to pad output.

  See Also:

  Constant Field Values

• PAD

  protected final byte PAD

  See Also:

  Constant Field Values

• lineLength

  protected final int lineLength

  Chunksize for encoding. Not used when decoding. A value of zero or less implies no chunking of the encoded data. Rounded down to nearest multiple of encodedBlockSize.

Constructor Detail

• BaseNCodec

  protected BaseNCodec(int unencodedBlockSize,
            int encodedBlockSize,
            int lineLength,
            int chunkSeparatorLength)

  Note lineLength is rounded down to the nearest multiple of encodedBlockSize If chunkSeparatorLength is zero, then chunking is disabled.

  Parameters:

  unencodedBlockSize - the size of an unencoded block (e.g. Base64 = 3)

  encodedBlockSize - the size of an encoded block (e.g. Base64 = 4)

  lineLength - if > 0, use chunking with a length lineLength

  chunkSeparatorLength - the chunk separator length, if relevant

Method Detail

• getDefaultBufferSize

  protected int getDefaultBufferSize()

  Get the default buffer size. Can be overridden.

  Returns:

  DEFAULT_BUFFER_SIZE

• ensureBufferSize

  protected byte[] ensureBufferSize(int size,
                        org.apache.commons.codec.binary.BaseNCodec.Context context)

  Ensure that the buffer has room for size bytes

  Parameters:

  size - minimum spare space required

  context - the context to be used

• isWhiteSpace

  protected static boolean isWhiteSpace(byte byteToCheck)

  Checks if a byte value is whitespace or not. Whitespace is taken to mean: space, tab, CR, LF

  Parameters:

  byteToCheck - the byte to check

  Returns:

  true if byte is whitespace, false otherwise

• encode

  public Object encode(Object obj)
                throws EncoderException

  Encodes an Object using the Base-N algorithm. This method is provided in order to satisfy the requirements of the Encoder interface, and will throw an EncoderException if the supplied object is not of type byte[].

  Specified by:

  encode in interface  Encoder

  Parameters:

  obj - Object to encode

  Returns:

  An object (of type byte[]) containing the Base-N encoded data which corresponds to the byte[] supplied.

  Throws:

  EncoderException - if the parameter supplied is not of type byte[]

• encodeToString

  public String encodeToString(byte[] pArray)

  Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet. Uses UTF8 encoding.

  Parameters:

  pArray - a byte array containing binary data

  Returns:

  A String containing only Base-N character data

• encodeAsString

  public String encodeAsString(byte[] pArray)

  Encodes a byte[] containing binary data, into a String containing characters in the appropriate alphabet. Uses UTF8 encoding.

  Parameters:

  pArray - a byte array containing binary data

  Returns:

  String containing only character data in the appropriate alphabet.

• decode

  public Object decode(Object obj)
                throws DecoderException

  Decodes an Object using the Base-N algorithm. This method is provided in order to satisfy the requirements of the Decoder interface, and will throw a DecoderException if the supplied object is not of type byte[] or String.

  Specified by:

  decode in interface  Decoder

  Parameters:

  obj - Object to decode

  Returns:

  An object (of type byte[]) containing the binary data which corresponds to the byte[] or String supplied.

  Throws:

  DecoderException - if the parameter supplied is not of type byte[]

• decode

  public byte[] decode(String pArray)

  Decodes a String containing characters in the Base-N alphabet.

  Parameters:

  pArray - A String containing Base-N character data

  Returns:

  a byte array containing binary data

• decode

  public byte[] decode(byte[] pArray)

  Decodes a byte[] containing characters in the Base-N alphabet.

  Specified by:

  decode in interface  BinaryDecoder

  Parameters:

  pArray - A byte array containing Base-N character data

  Returns:

  a byte array containing binary data

• encode

  public byte[] encode(byte[] pArray)

  Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.

  Specified by:

  encode in interface  BinaryEncoder

  Parameters:

  pArray - a byte array containing binary data

  Returns:

  A byte array containing only the basen alphabetic character data

• isInAlphabet

  protected abstract boolean isInAlphabet(byte value)

  Returns whether or not the octet is in the current alphabet. Does not allow whitespace or pad.

  Parameters:

  value - The value to test

  Returns:

  true if the value is defined in the current alphabet, false otherwise.

• isInAlphabet

  public boolean isInAlphabet(byte[] arrayOctet,
                     boolean allowWSPad)

  Tests a given byte array to see if it contains only valid characters within the alphabet. The method optionally treats whitespace and pad as valid.

  Parameters:

  arrayOctet - byte array to test

  allowWSPad - if true, then whitespace and PAD are also allowed

  Returns:

  true if all bytes are valid characters in the alphabet or if the byte array is empty; false, otherwise

• isInAlphabet

  public boolean isInAlphabet(String basen)

  Tests a given String to see if it contains only valid characters within the alphabet. The method treats whitespace and PAD as valid.

  Parameters:

  basen - String to test

  Returns:

  true if all characters in the String are valid characters in the alphabet or if the String is empty; false, otherwise

  See Also:

  isInAlphabet(byte[], boolean)

• containsAlphabetOrPad

  protected boolean containsAlphabetOrPad(byte[] arrayOctet)

  Tests a given byte array to see if it contains any characters within the alphabet or PAD. Intended for use in checking line-ending arrays

  Parameters:

  arrayOctet - byte array to test

  Returns:

  true if any byte is a valid character in the alphabet or PAD; false otherwise

• getEncodedLength

  public long getEncodedLength(byte[] pArray)

  Calculates the amount of space needed to encode the supplied array.

  Parameters:

  pArray - byte[] array which will later be encoded

  Returns:

  amount of space needed to encoded the supplied array. Returns a long since a max-len array will require > Integer.MAX_VALUE