Class HunspellStemFilter

  • All Implemented Interfaces:
    Closeable, AutoCloseable

    public final class HunspellStemFilter
    extends TokenFilter
    TokenFilter that uses hunspell affix rules and words to stem tokens. Since hunspell supports a word having multiple stems, this filter can emit multiple tokens for each consumed token
    • Constructor Detail

      • HunspellStemFilter

        public HunspellStemFilter​(TokenStream input,
                                  HunspellDictionary dictionary)
        Creates a new HunspellStemFilter that will stem tokens from the given TokenStream using affix rules in the provided HunspellDictionary
        Parameters:
        input - TokenStream whose tokens will be stemmed
        dictionary - HunspellDictionary containing the affix rules and words that will be used to stem the tokens
      • HunspellStemFilter

        public HunspellStemFilter​(TokenStream input,
                                  HunspellDictionary dictionary,
                                  boolean dedup)
        Creates a new HunspellStemFilter that will stem tokens from the given TokenStream using affix rules in the provided HunspellDictionary
        Parameters:
        input - TokenStream whose tokens will be stemmed
        dictionary - HunspellDictionary containing the affix rules and words that will be used to stem the tokens
        dedup - true if only unique terms should be output.
    • Method Detail

      • incrementToken

        public boolean incrementToken()
                               throws IOException
        Consumers (i.e., IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate AttributeImpls with the attributes of the next token.

        The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use AttributeSource.captureState() to create a copy of the current attribute state.

        This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to AttributeSource.addAttribute(Class) and AttributeSource.getAttribute(Class), references to all AttributeImpls that this stream uses should be retrieved during instantiation.

        To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in TokenStream.incrementToken().

        Specified by:
        incrementToken in class TokenStream
        Returns:
        false for end of stream; true otherwise
        Throws:
        IOException