Class NGramTokenizer

  • All Implemented Interfaces:
    Closeable, AutoCloseable

    public final class NGramTokenizer
    extends Tokenizer
    Tokenizes the input into n-grams of the given size(s).
    • Constructor Detail

      • NGramTokenizer

        public NGramTokenizer​(Reader input,
                              int minGram,
                              int maxGram)
        Creates NGramTokenizer with given min and max n-grams.
        Parameters:
        input - Reader holding the input to be tokenized
        minGram - the smallest n-gram to generate
        maxGram - the largest n-gram to generate
      • NGramTokenizer

        public NGramTokenizer​(AttributeSource source,
                              Reader input,
                              int minGram,
                              int maxGram)
        Creates NGramTokenizer with given min and max n-grams.
        Parameters:
        source - AttributeSource to use
        input - Reader holding the input to be tokenized
        minGram - the smallest n-gram to generate
        maxGram - the largest n-gram to generate
      • NGramTokenizer

        public NGramTokenizer​(Reader input)
        Creates NGramTokenizer with default min and max n-grams.
        Parameters:
        input - Reader holding the input to be tokenized
    • Method Detail

      • incrementToken

        public boolean incrementToken()
                               throws IOException
        Returns the next token in the stream, or null at EOS.
        Specified by:
        incrementToken in class TokenStream
        Returns:
        false for end of stream; true otherwise
        Throws:
        IOException
      • end

        public 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.

        Overrides:
        end in class TokenStream
      • reset

        public void reset()
                   throws IOException
        Description copied from class: TokenStream
        Resets this stream to the beginning. This is an optional operation, so subclasses may or may not implement this method. TokenStream.reset() is not needed for the standard indexing process. However, if the tokens of a TokenStream are intended to be consumed more than once, it is necessary to implement TokenStream.reset(). Note that if your TokenStream caches tokens and feeds them back again after a reset, it is imperative that you clone the tokens when you store them away (on the first pass) as well as when you return them (on future passes after TokenStream.reset()).
        Overrides:
        reset in class TokenStream
        Throws:
        IOException