Class CJKTokenizer

  • All Implemented Interfaces:, java.lang.AutoCloseable

    public final class CJKTokenizer
    extends Tokenizer
    Use StandardTokenizer, CJKWidthFilter, CJKBigramFilter, and LowerCaseFilter instead.
    CJKTokenizer is designed for Chinese, Japanese, and Korean languages.

    The tokens returned are every two adjacent characters with overlap match.

    Example: "java C1C2C3C4" will be segmented to: "java" "C1C2" "C2C3" "C3C4".

    Additionally, the following is applied to Latin text (such as English):
    • Text is converted to lowercase.
    • Numeric digits, '+', '#', and '_' are tokenized as letters.
    • Full-width forms are converted to half-width forms.
    For more info on Asian language (Chinese, Japanese, and Korean) text segmentation: please search google
    • Constructor Detail

      • CJKTokenizer

        public CJKTokenizer​( in)
        Construct a token stream processing the given input.
        in - I/O reader
    • Method Detail

      • incrementToken

        public boolean incrementToken()
        Returns true for the next token in the stream, or false at EOS. See for detail.
        Specified by:
        incrementToken in class TokenStream
        false for end of stream, true otherwise
        Throws: - - throw IOException when read error
        happened in the InputStream
      • end

        public final void end()
        Description copied from class: TokenStream
        This method is called by the consumer after the last token has been consumed, after TokenStream.incrementToken() returned false (using the new TokenStream API). Streams implementing the old API should upgrade to use this feature.

        This method can be used to perform any end-of-stream operations, such as setting the final offset of a stream. The final offset of a stream might differ from the offset of the last token eg in case one or more whitespaces followed after the last token, but a WhitespaceTokenizer was used.

        Additionally any skipped positions (such as those removed by a stopfilter) can be applied to the position increment, or any adjustment of other attributes where the end-of-stream value may be important.

        If you override this method, always call super.end().

        end in class TokenStream
        Throws: - If an I/O error occurs
      • reset

        public void reset()
        Description copied from class: TokenStream
        This method is called by a consumer before it begins consumption using TokenStream.incrementToken().

        Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.

        If you override this method, always call super.reset(), otherwise some internal state will not be correctly reset (e.g., Tokenizer will throw IllegalStateException on further usage).

        reset in class Tokenizer