org.apache.lucene.analysis.shingle
Class ShingleAnalyzerWrapper

java.lang.Object
  org.apache.lucene.analysis.Analyzer
      org.apache.lucene.analysis.shingle.ShingleAnalyzerWrapper

All Implemented Interfaces:

Closeable

public final class ShingleAnalyzerWrapper
extends Analyzer

A ShingleAnalyzerWrapper wraps a ShingleFilter around another Analyzer.

A shingle is another name for a token based n-gram.

Constructor Summary

ShingleAnalyzerWrapper(Analyzer defaultAnalyzer)

ShingleAnalyzerWrapper(Analyzer defaultAnalyzer, int maxShingleSize)

ShingleAnalyzerWrapper(Analyzer defaultAnalyzer, int minShingleSize, int maxShingleSize)

ShingleAnalyzerWrapper(Version matchVersion)
Wraps StandardAnalyzer.

ShingleAnalyzerWrapper(Version matchVersion, int minShingleSize, int maxShingleSize)
Wraps StandardAnalyzer.

Method Summary

int	getMaxShingleSize() The max shingle (token ngram) size
int	getMinShingleSize() The min shingle (token ngram) size
String	getTokenSeparator()
boolean	isOutputUnigrams()
boolean	isOutputUnigramsIfNoShingles()
TokenStream	reusableTokenStream(String fieldName, Reader reader) Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method.
void	setMaxShingleSize(int maxShingleSize) Set the maximum size of output shingles (default: 2)
void	setMinShingleSize(int minShingleSize) Set the min shingle size (default: 2).
void	setOutputUnigrams(boolean outputUnigrams) Shall the filter pass the original tokens (the "unigrams") to the output stream?
void	setOutputUnigramsIfNoShingles(boolean outputUnigramsIfNoShingles) Shall we override the behavior of outputUnigrams==false for those times when no shingles are available (because there are fewer than minShingleSize tokens in the input stream)? (default: false.)
void	setTokenSeparator(String tokenSeparator) Sets the string to use when joining adjacent tokens to form a shingle
TokenStream	tokenStream(String fieldName, Reader reader) Creates a TokenStream which tokenizes all the text in the provided Reader.

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

close, getOffsetGap, getPositionIncrementGap, getPreviousTokenStream, setPreviousTokenStream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ShingleAnalyzerWrapper

public ShingleAnalyzerWrapper(Analyzer defaultAnalyzer)

ShingleAnalyzerWrapper

public ShingleAnalyzerWrapper(Analyzer defaultAnalyzer,
                              int maxShingleSize)

ShingleAnalyzerWrapper

public ShingleAnalyzerWrapper(Analyzer defaultAnalyzer,
                              int minShingleSize,
                              int maxShingleSize)

ShingleAnalyzerWrapper

public ShingleAnalyzerWrapper(Version matchVersion)

Wraps StandardAnalyzer.

ShingleAnalyzerWrapper

public ShingleAnalyzerWrapper(Version matchVersion,
                              int minShingleSize,
                              int maxShingleSize)

Wraps StandardAnalyzer.

Method Detail

getMaxShingleSize

public int getMaxShingleSize()

The max shingle (token ngram) size

Returns:

The max shingle (token ngram) size

setMaxShingleSize

public void setMaxShingleSize(int maxShingleSize)

Set the maximum size of output shingles (default: 2)

Parameters:

maxShingleSize - max shingle size

getMinShingleSize

public int getMinShingleSize()

The min shingle (token ngram) size

Returns:

The min shingle (token ngram) size

setMinShingleSize

public void setMinShingleSize(int minShingleSize)

Set the min shingle size (default: 2).

This method requires that the passed in minShingleSize is not greater than maxShingleSize, so make sure that maxShingleSize is set before calling this method.

Parameters:

minShingleSize - min size of output shingles

getTokenSeparator

public String getTokenSeparator()

setTokenSeparator

public void setTokenSeparator(String tokenSeparator)

Sets the string to use when joining adjacent tokens to form a shingle

Parameters:

tokenSeparator - used to separate input stream tokens in output shingles

isOutputUnigrams

public boolean isOutputUnigrams()

setOutputUnigrams

public void setOutputUnigrams(boolean outputUnigrams)

Shall the filter pass the original tokens (the "unigrams") to the output stream?

Parameters:

outputUnigrams - Whether or not the filter shall pass the original tokens to the output stream

isOutputUnigramsIfNoShingles

public boolean isOutputUnigramsIfNoShingles()

setOutputUnigramsIfNoShingles

public void setOutputUnigramsIfNoShingles(boolean outputUnigramsIfNoShingles)

Shall we override the behavior of outputUnigrams==false for those times when no shingles are available (because there are fewer than minShingleSize tokens in the input stream)? (default: false.)

Note that if outputUnigrams==true, then unigrams are always output, regardless of whether any shingles are available.

Parameters:

outputUnigramsIfNoShingles - Whether or not to output a single unigram when no shingles are available.

tokenStream

public TokenStream tokenStream(String fieldName,
                               Reader reader)

Description copied from class: Analyzer

Creates a TokenStream which tokenizes all the text in the provided Reader. Must be able to handle null field name for backward compatibility.

Specified by:

tokenStream in class Analyzer

reusableTokenStream

public TokenStream reusableTokenStream(String fieldName,
                                       Reader reader)
                                throws IOException

Description copied from class: Analyzer

Creates a TokenStream that is allowed to be re-used from the previous time that the same thread called this method. Callers that do not need to use more than one TokenStream at the same time from this analyzer should use this method for better performance.

Overrides:

reusableTokenStream in class Analyzer

Throws:

IOException