org.apache.lucene.analysis.snowball.SnowballFilter Java Examples

@Override
public TokenStream create(TokenStream ts) {
	// Try to add a snowball filter
	SnowballProgram stemmer = language.getStemmer();

	if (stemmer != null)
		return new SnowballFilter(ts, stemmer);
	else
		return ts;
}
 

@Override
public void setUp() throws Exception {
  super.setUp();
  a = new Analyzer() {
    @Override
    protected TokenStreamComponents createComponents(String fieldName) {
      Tokenizer tokenizer = new MockTokenizer(MockTokenizer.WHITESPACE, false);
      return new TokenStreamComponents(tokenizer, new SnowballFilter(tokenizer, new LithuanianStemmer()));
    }
  };
}
 

@Override
public List<PreConfiguredTokenFilter> getPreConfiguredTokenFilters() {
    List<PreConfiguredTokenFilter> filters = new ArrayList<>();
    filters.add(PreConfiguredTokenFilter.singleton("apostrophe", false, ApostropheFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("arabic_normalization", true, ArabicNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("arabic_stem", false, ArabicStemFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("asciifolding", true, ASCIIFoldingFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("bengali_normalization", true, BengaliNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("brazilian_stem", false, BrazilianStemFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("cjk_bigram", false, CJKBigramFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("cjk_width", true, CJKWidthFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("classic", false, ClassicFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton(
        "common_grams",
        false,
        input -> new CommonGramsFilter(input, CharArraySet.EMPTY_SET)));
    filters.add(PreConfiguredTokenFilter.singleton("czech_stem", false, CzechStemFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("decimal_digit", true, DecimalDigitFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("delimited_payload_filter", false, input ->
            new DelimitedPayloadTokenFilter(input,
                    DelimitedPayloadTokenFilterFactory.DEFAULT_DELIMITER,
                    DelimitedPayloadTokenFilterFactory.DEFAULT_ENCODER)));
    filters.add(PreConfiguredTokenFilter.singleton("delimited_payload", false, input ->
            new DelimitedPayloadTokenFilter(input,
                    DelimitedPayloadTokenFilterFactory.DEFAULT_DELIMITER,
                    DelimitedPayloadTokenFilterFactory.DEFAULT_ENCODER)));
    filters.add(PreConfiguredTokenFilter.singleton("dutch_stem", false, input -> new SnowballFilter(input, new DutchStemmer())));
    filters.add(PreConfiguredTokenFilter.singleton(
        "edge_ngram",
        false,
        input -> new EdgeNGramTokenFilter(input, EdgeNGramTokenFilterFactory.SIDE_FRONT, EdgeNGramTokenFilterFactory.SIDE_BACK, EdgeNGramTokenFilter.DEFAULT_PRESERVE_ORIGINAL)));
    filters.add(PreConfiguredTokenFilter.singleton(
        "elision",
        true,
        input -> new ElisionFilter(input, FrenchAnalyzer.DEFAULT_ARTICLES))
    );
    filters.add(PreConfiguredTokenFilter.singleton("french_stem", false, input -> new SnowballFilter(input, new FrenchStemmer())));
    filters.add(PreConfiguredTokenFilter.singleton("german_normalization", true, GermanNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("german_stem", false, GermanStemFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("hindi_normalization", true, HindiNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("indic_normalization", true, IndicNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("keyword_repeat", false, KeywordRepeatFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("kstem", false, KStemFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("length", false, input ->
        new LengthFilter(input, 0, Integer.MAX_VALUE)));  // TODO this one seems useless
    filters.add(PreConfiguredTokenFilter.singleton(
        "limit",
        false,
        input -> new LimitTokenCountFilter(
            input,
            LimitTokenCountFilterFactory.DEFAULT_MAX_TOKEN_COUNT,
            LimitTokenCountFilterFactory.DEFAULT_CONSUME_ALL_TOKENS)
        )
    );
    filters.add(PreConfiguredTokenFilter.singleton("ngram", false, reader -> new NGramTokenFilter(reader, 1, 2, false)));
    filters.add(PreConfiguredTokenFilter.singleton("persian_normalization", true, PersianNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("porter_stem", false, PorterStemFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("reverse", false, ReverseStringFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("russian_stem", false, input -> new SnowballFilter(input, "Russian")));
    filters.add(PreConfiguredTokenFilter.singleton("scandinavian_folding", true, ScandinavianFoldingFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("scandinavian_normalization", true, ScandinavianNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("shingle", false, input -> {
        TokenStream ts = new ShingleFilter(input);
        /**
         * We disable the graph analysis on this token stream
         * because it produces shingles of different size.
         * Graph analysis on such token stream is useless and dangerous as it may create too many paths
         * since shingles of different size are not aligned in terms of positions.
         */
        ts.addAttribute(DisableGraphAttribute.class);
        return ts;
    }));
    filters.add(PreConfiguredTokenFilter.singleton("snowball", false, input -> new SnowballFilter(input, "English")));
    filters.add(PreConfiguredTokenFilter.singleton("sorani_normalization", true, SoraniNormalizationFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("stemmer", false, PorterStemFilter::new));
    // The stop filter is in lucene-core but the English stop words set is in lucene-analyzers-common
    filters.add(PreConfiguredTokenFilter.singleton("stop", false, input -> new StopFilter(input, EnglishAnalyzer.ENGLISH_STOP_WORDS_SET)));
    filters.add(PreConfiguredTokenFilter.singleton("trim", true, TrimFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("truncate", false, input -> new TruncateTokenFilter(input, 10)));
    filters.add(PreConfiguredTokenFilter.singleton("type_as_payload", false, TypeAsPayloadTokenFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("unique", false, UniqueTokenFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("uppercase", true, UpperCaseFilter::new));
    filters.add(PreConfiguredTokenFilter.singleton("word_delimiter", false, input ->
            new WordDelimiterFilter(input,
                    WordDelimiterFilter.GENERATE_WORD_PARTS
                  | WordDelimiterFilter.GENERATE_NUMBER_PARTS
                  | WordDelimiterFilter.SPLIT_ON_CASE_CHANGE
                  | WordDelimiterFilter.SPLIT_ON_NUMERICS
                  | WordDelimiterFilter.STEM_ENGLISH_POSSESSIVE, null)));
    filters.add(PreConfiguredTokenFilter.singleton("word_delimiter_graph", false, input ->
            new WordDelimiterGraphFilter(input,
                    WordDelimiterGraphFilter.GENERATE_WORD_PARTS
                  | WordDelimiterGraphFilter.GENERATE_NUMBER_PARTS
                  | WordDelimiterGraphFilter.SPLIT_ON_CASE_CHANGE
                  | WordDelimiterGraphFilter.SPLIT_ON_NUMERICS
                  | WordDelimiterGraphFilter.STEM_ENGLISH_POSSESSIVE, null)));
    return filters;
}
 

@Override
public TokenStream create(TokenStream tokenStream) {
    return new SnowballFilter(tokenStream, "Russian");
}
 

@Override
public TokenStream create(TokenStream tokenStream) {
    return new SnowballFilter(tokenStream, language);
}
 

public void testBasic() throws IOException {
  TokenStream ts = new RemoveDuplicatesTokenFilter(new SnowballFilter(new KeywordRepeatFilter(
      whitespaceMockTokenizer("the birds are flying")), "English"));
  assertTokenStreamContents(ts, new String[] { "the", "birds", "bird", "are", "flying", "fli"}, new int[] {1,1,0,1,1,0});
}
 

public void testComposition() throws IOException {
  TokenStream ts = new RemoveDuplicatesTokenFilter(new SnowballFilter(new KeywordRepeatFilter(new KeywordRepeatFilter(
      whitespaceMockTokenizer("the birds are flying"))), "English"));
  assertTokenStreamContents(ts, new String[] { "the", "birds", "bird", "are", "flying", "fli"}, new int[] {1,1,0,1,1,0});
}
 

@Override
public TokenStream create(TokenStream tokenStream) {
    return new SnowballFilter(tokenStream, "Russian");
}
 

@Override
public TokenStream create(TokenStream tokenStream) {
    return new SnowballFilter(tokenStream, language);
}