Package org.apache.lucene.analysis.pattern

Class PatternTokenizerFactory

java.lang.Object
org.apache.lucene.analysis.util.AbstractAnalysisFactory
org.apache.lucene.analysis.util.TokenizerFactory
org.apache.lucene.analysis.pattern.PatternTokenizerFactory
public class PatternTokenizerFactory extends TokenizerFactory
Factory for PatternTokenizer. This tokenizer uses regex pattern matching to construct distinct tokens for the input stream. It takes two arguments: "pattern" and "group".

  • "pattern" is the regular expression.
  • "group" says which group to extract into tokens.

group=-1 (the default) is equivalent to "split". In this case, the tokens will be equivalent to the output from (without empty tokens): String.split(java.lang.String)

Using group >= 0 selects the matching group as the token. For example, if you have:

  pattern = \'([^\']+)\'
  group = 0
  input = aaa 'bbb' 'ccc'
the output will be two tokens: 'bbb' and 'ccc' (including the ' marks). With the same input but using group=1, the output would be: bbb and ccc (no ' marks)

NOTE: This Tokenizer does not output tokens that are of zero length.

 <fieldType name="text_ptn" class="solr.TextField" positionIncrementGap="100">
   <analyzer>
     <tokenizer class="solr.PatternTokenizerFactory" pattern="\'([^\']+)\'" group="1"/>
   </analyzer>
 </fieldType>
Since:
solr1.2
See Also: