Package io.permazen.encoding

Class CharacterEncoding

java.lang.Object
io.permazen.encoding.AbstractEncoding<T>
io.permazen.encoding.PrimitiveEncoding<Character>
io.permazen.encoding.CharacterEncoding
All Implemented Interfaces:
Encoding<Character>, NaturalSortAware, Serializable, Comparator<Character>
public class CharacterEncoding extends PrimitiveEncoding<Character>
Character type.
See Also:

  • Constructor Details

    • CharacterEncoding

      public CharacterEncoding(EncodingId encodingId)

  • Method Details

    • read

      public Character read(ByteReader reader)
      Description copied from interface: Encoding
      Read a value from the given input.
      Parameters:
      reader - byte input
      Returns:
      decoded value (possibly null)

    • write

      public void write(ByteWriter writer, Character value)
      Description copied from interface: Encoding
      Write a value to the given output.
      Parameters:
      writer - byte output
      value - value to write (possibly null)

    • skip

      public void skip(ByteReader reader)
      Description copied from interface: Encoding
      Read and discard a byte[] encoded value from the given input.

      If the value skipped over is invalid, this method may, but is not required to, throw IllegalArgumentException.

      If the value skipped over is truncated, this method must throw IndexOutOfBoundsException.

      Parameters:
      reader - byte input

    • toString

      public String toString(Character value)
      Description copied from interface: Encoding
      Encode a non-null value as a String for later decoding by fromString().

      Each of the characters in the returned String, when decoded as 32-bit Unicode codepoints, must contain only valid XML characters (see XMLUtil.isValidChar(int)).

      Specified by:
      toString in interface Encoding<Character>
      Overrides:
      toString in class PrimitiveEncoding<Character>
      Parameters:
      value - actual value, never null
      Returns:
      string encoding of value acceptable to fromString()
      See Also:

    • fromString

      public Character fromString(String string)
      Description copied from interface: Encoding
      Parse a non-null value previously encoded by toString(T).
      Specified by:
      fromString in interface Encoding<Character>
      Overrides:
      fromString in class PrimitiveEncoding<Character>
      Parameters:
      string - non-null value previously encoded as a String by toString(T)
      Returns:
      actual value

    • hasPrefix0x00

      public boolean hasPrefix0x00()
      Description copied from interface: Encoding
      Determine whether any of this encoding's encoded values start with a 0x00 byte. Certain optimizations are possible when this is not the case. It is safe for this method to always return true.

      Note: changing the result of this method may result in an incompatible encoding if this encoding is wrapped in another class.

      Returns:
      true if an encoded value starting with 0x00 exists

    • hasPrefix0xff

      public boolean hasPrefix0xff()
      Description copied from interface: Encoding
      Determine whether any of this encoding's encoded values start with a 0xff byte. Certain optimizations are possible when this is not the case. It is safe for this method to always return true.

      Note: changing the result of this method may result in an incompatible encoding if this encoding is wrapped in another class.

      Returns:
      true if an encoded value starting with 0xff exists

    • getFixedWidth

      public OptionalInt getFixedWidth()
      Description copied from interface: Encoding
      Get the fixed width of this encoding, if any.

      Some encodings encode every value into the same number of bytes. For such encodings, this method returns that number. For variable width encodings, this method must return empty.

      Returns:
      the number of bytes of every encoded value, or empty if the encoding length varies

    • convert

      public <S> Character convert(Encoding<S> type, S value)
      Description copied from interface: Encoding
      Attempt to convert a value from the given Encoding into a value of this Encoding.

      For a non-null value, the implementation in Encoding first checks whether the value is already a valid value for this encoding; if so, the value is returned. Otherwise, it invokes encoding.toString(value) to convert value into a String, and then attempts to parse that string via this.fromString(); if the parse fails, an IllegalArgumentException is thrown. Note this means that any value will convert successfully to a String, as long as it doesn't contain an invalid escape sequence (see StringEncoding.toString(java.lang.String)).

      If value is null, the implementation in Encoding returns null, unless this encoding does not support null values, in which case an IllegalArgumentException is thrown.

      Permazen's built-in encodings include the following conversions:

      • Non-boolean Primitive types:
        • Convert from other non-boolean primitive types as if by the corresponding Java cast
        • Convert from boolean by converting to zero (if false) or one (if true)
      • Boolean: converts from other primitive types as if by value != 0
      • A char[] array and a String are convertible to each other
      • A char and a String of length one are convertible to each other (other Strings are not)
      • Arrays: converted by converting each array element individually (if possible)
      Specified by:
      convert in interface Encoding<Character>
      Overrides:
      convert in class PrimitiveEncoding<Character>
      Type Parameters:
      S - source encoding
      Parameters:
      type - the Encoding of value
      value - the value to convert
      Returns:
      value converted to this instance's type

    • convertNumber

      protected Character convertNumber(Number value)
      Specified by:
      convertNumber in class PrimitiveEncoding<Character>