org.apache.lucene.analysis.util
Class FilteringTokenFilter

java.lang.Object
  org.apache.lucene.util.AttributeSource
      org.apache.lucene.analysis.TokenStream
          org.apache.lucene.analysis.TokenFilter
              org.apache.lucene.analysis.util.FilteringTokenFilter

All Implemented Interfaces:

Closeable

Direct Known Subclasses:

CodepointCountFilter, KeepWordFilter, LengthFilter, StopFilter, TypeTokenFilter

public abstract class FilteringTokenFilter
extends TokenFilter

Abstract base class for TokenFilters that may remove tokens. You have to implement accept() and return a boolean if the current token should be preserved. incrementToken() uses this method to decide if a token should be passed to the caller.

As of Lucene 4.4, an IllegalArgumentException is thrown when trying to disable position increments when filtering terms.

Nested Class Summary

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

AttributeSource.AttributeFactory, AttributeSource.State

Field Summary

protected Version

version

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

input

Constructor Summary

FilteringTokenFilter(Version version, boolean enablePositionIncrements, TokenStream input)
Deprecated. enablePositionIncrements=false is not supported anymore as of Lucene 4.4

FilteringTokenFilter(Version version, TokenStream in)
Create a new FilteringTokenFilter.

Method Summary

protected abstract boolean	accept() Override this method and return if the current input token should be returned by incrementToken().
void	end()
boolean	getEnablePositionIncrements()
boolean	incrementToken()
void	reset()
void	setEnablePositionIncrements(boolean enable) Deprecated. enablePositionIncrements=false is not supported anymore as of Lucene 4.4

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

close

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

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

Methods inherited from class java.lang.Object

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

Field Detail

version

protected final Version version

Constructor Detail

FilteringTokenFilter

@Deprecated
public FilteringTokenFilter(Version version,
                                       boolean enablePositionIncrements,
                                       TokenStream input)

Deprecated. enablePositionIncrements=false is not supported anymore as of Lucene 4.4

Create a new FilteringTokenFilter.

Parameters:

version - the Lucene match version

enablePositionIncrements - whether to increment position increments when filtering out terms

input - the input to consume

FilteringTokenFilter

public FilteringTokenFilter(Version version,
                            TokenStream in)

Create a new FilteringTokenFilter.

Parameters:

version - the Lucene match version

in - the TokenStream to consume

Method Detail

accept

protected abstract boolean accept()
                           throws IOException

Override this method and return if the current input token should be returned by incrementToken().

Throws:

IOException

incrementToken

public final boolean incrementToken()
                             throws IOException

Specified by:

incrementToken in class TokenStream

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class TokenFilter

Throws:

IOException

getEnablePositionIncrements

public boolean getEnablePositionIncrements()

See Also:

setEnablePositionIncrements(boolean)

setEnablePositionIncrements

@Deprecated
public void setEnablePositionIncrements(boolean enable)

Deprecated. enablePositionIncrements=false is not supported anymore as of Lucene 4.4

If true, this TokenFilter will preserve positions of the incoming tokens (ie, accumulate and set position increments of the removed tokens). Generally, true is best as it does not lose information (positions of the original tokens) during indexing.

When set, when a token is stopped (omitted), the position increment of the following token is incremented.

NOTE: be sure to also set org.apache.lucene.queryparser.classic.QueryParser#setEnablePositionIncrements if you use QueryParser to create queries.

end

public void end()
         throws IOException

Overrides:

end in class TokenFilter

Throws:

IOException