org.apache.lucene.analysis

Class AnalyzerWrapper

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.AnalyzerWrapper

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

LimitTokenCountAnalyzer, PerFieldAnalyzerWrapper, QueryAutoStopWordAnalyzer, ShingleAnalyzerWrapper

public abstract class AnalyzerWrapper
extends Analyzer

Extension to Analyzer suitable for Analyzers which wrap other Analyzers.

getWrappedAnalyzer(String) allows the Analyzer to wrap multiple Analyzers which are selected on a per field basis.

wrapComponents(String, Analyzer.TokenStreamComponents) allows the TokenStreamComponents of the wrapped Analyzer to then be wrapped (such as adding a new TokenFilter to form new TokenStreamComponents.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.analysis.Analyzer

Analyzer.GlobalReuseStrategy, Analyzer.PerFieldReuseStrategy, Analyzer.ReuseStrategy, Analyzer.TokenStreamComponents

Field Summary

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

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Method Summary

Modifier and Type	Method and Description
int	getOffsetGap(String fieldName) Just like Analyzer.getPositionIncrementGap(java.lang.String), except for Token offsets instead.
int	getPositionIncrementGap(String fieldName) Invoked before indexing a IndexableField instance if terms have already been added to that field.
Reader	initReader(String fieldName, Reader reader) Override this if you want to add a CharFilter chain.

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

close, getReuseStrategy, tokenStream, tokenStream

Methods inherited from class java.lang.Object

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

Method Detail

getPositionIncrementGap

public int getPositionIncrementGap(String fieldName)

Description copied from class: Analyzer

Invoked before indexing a IndexableField instance if terms have already been added to that field. This allows custom analyzers to place an automatic position increment gap between IndexbleField instances using the same field name. The default value position increment gap is 0. With a 0 position increment gap and the typical default token position increment of 1, all terms in a field, including across IndexableField instances, are in successive positions, allowing exact PhraseQuery matches, for instance, across IndexableField instance boundaries.

Overrides:

getPositionIncrementGap in class Analyzer

Parameters:

fieldName - IndexableField name being indexed.

Returns:

position increment gap, added to the next token emitted from Analyzer.tokenStream(String,Reader). This value must be >= 0.

getOffsetGap

public int getOffsetGap(String fieldName)

Description copied from class: Analyzer

Just like Analyzer.getPositionIncrementGap(java.lang.String), except for Token offsets instead. By default this returns 1. This method is only called if the field produced at least one token for indexing.

Overrides:

getOffsetGap in class Analyzer

Parameters:

fieldName - the field just indexed

Returns:

offset gap, added to the next token emitted from Analyzer.tokenStream(String,Reader). This value must be >= 0.

initReader

public final Reader initReader(String fieldName,
                               Reader reader)

Description copied from class: Analyzer

Override this if you want to add a CharFilter chain.

The default implementation returns reader unchanged.

Parameters:

fieldName - IndexableField name being indexed

reader - original Reader

Returns:

reader, optionally decorated with CharFilter(s)