org.apache.solr.analysis
Class CommonGramsQueryFilter

java.lang.Object
  org.apache.lucene.util.AttributeSource
      org.apache.lucene.analysis.TokenStream
          org.apache.lucene.analysis.TokenFilter
              org.apache.solr.analysis.BufferedTokenStream
                  org.apache.solr.analysis.CommonGramsQueryFilter

All Implemented Interfaces:

java.io.Closeable

public class CommonGramsQueryFilter
extends BufferedTokenStream

Wrap a CommonGramsFilter optimizing phrase queries by only returning single words when they are not a member of a bigram.

Example:

• query input to CommonGramsFilter: "the rain in spain falls mainly"
• output of CommomGramsFilter/input to CommonGramsQueryFilter: |"the, "the-rain"|"rain" "rain-in"|"in, "in-spain"|"spain"|"falls"|"mainly"
• output of CommonGramsQueryFilter:"the-rain", "rain-in" ,"in-spain", "falls", "mainly"

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

org.apache.lucene.util.AttributeSource.AttributeFactory, org.apache.lucene.util.AttributeSource.State

Field Summary

Fields inherited from class org.apache.lucene.analysis.TokenFilter

input

Constructor Summary

CommonGramsQueryFilter(CommonGramsFilter input)
Constructor

Method Summary

org.apache.lucene.analysis.Token	process(org.apache.lucene.analysis.Token token) Output bigrams whenever possible to optimize queries.
void	reset()

Methods inherited from class org.apache.solr.analysis.BufferedTokenStream

incrementToken, output, peek, pushBack, read, write

Methods inherited from class org.apache.lucene.analysis.TokenFilter

close, end

Methods inherited from class org.apache.lucene.util.AttributeSource

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CommonGramsQueryFilter

public CommonGramsQueryFilter(CommonGramsFilter input)

Constructor

Parameters:

input - must be a CommonGramsFilter!

Method Detail

reset

public void reset()
           throws java.io.IOException

Overrides:

reset in class BufferedTokenStream

Throws:

java.io.IOException

process

public org.apache.lucene.analysis.Token process(org.apache.lucene.analysis.Token token)
                                         throws java.io.IOException

Output bigrams whenever possible to optimize queries. Only output unigrams when they are not a member of a bigram. Example:

• input: "the rain in spain falls mainly"
• output:"the-rain", "rain-in" ,"in-spain", "falls", "mainly"

  Specified by:

  process in class BufferedTokenStream

  Throws:

  java.io.IOException