Class HyphenatedWordsFilter
- java.lang.Object
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- org.apache.lucene.util.AttributeSource
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- org.apache.lucene.analysis.TokenStream
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- org.apache.lucene.analysis.TokenFilter
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- org.apache.lucene.analysis.miscellaneous.HyphenatedWordsFilter
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
,Unwrappable<TokenStream>
public final class HyphenatedWordsFilter extends TokenFilter
When the plain text is extracted from documents, we will often have many words hyphenated and broken into two lines. This is often the case with documents where narrow text columns are used, such as newsletters. In order to increase search efficiency, this filter puts hyphenated words broken into two lines back together. This filter should be used on indexing time only. Example field definition in schema.xml:<fieldtype name="text" class="solr.TextField" positionIncrementGap="100"> <analyzer type="index"> <tokenizer class="solr.WhitespaceTokenizerFactory"/> <filter class="solr.SynonymFilterFactory" synonyms="index_synonyms.txt" ignoreCase="true" expand="false"/> <filter class="solr.StopFilterFactory" ignoreCase="true"/> <filter class="solr.HyphenatedWordsFilterFactory"/> <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="1" catenateNumbers="1" catenateAll="0"/> <filter class="solr.LowerCaseFilterFactory"/> <filter class="solr.RemoveDuplicatesTokenFilterFactory"/> </analyzer> <analyzer type="query"> <tokenizer class="solr.WhitespaceTokenizerFactory"/> <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/> <filter class="solr.StopFilterFactory" ignoreCase="true"/> <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="0" catenateNumbers="0" catenateAll="0"/> <filter class="solr.LowerCaseFilterFactory"/> <filter class="solr.RemoveDuplicatesTokenFilterFactory"/> </analyzer> </fieldtype>
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
Fields Modifier and Type Field Description private boolean
exhausted
private java.lang.StringBuilder
hyphenated
private int
lastEndOffset
private OffsetAttribute
offsetAttribute
private AttributeSource.State
savedState
private CharTermAttribute
termAttribute
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Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
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Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
Constructors Constructor Description HyphenatedWordsFilter(TokenStream in)
Creates a new HyphenatedWordsFilter
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
incrementToken()
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token.void
reset()
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
.private void
unhyphenate()
Writes the joined unhyphenated term-
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, unwrap
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Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
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Field Detail
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termAttribute
private final CharTermAttribute termAttribute
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offsetAttribute
private final OffsetAttribute offsetAttribute
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hyphenated
private final java.lang.StringBuilder hyphenated
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savedState
private AttributeSource.State savedState
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exhausted
private boolean exhausted
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lastEndOffset
private int lastEndOffset
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Constructor Detail
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HyphenatedWordsFilter
public HyphenatedWordsFilter(TokenStream in)
Creates a new HyphenatedWordsFilter- Parameters:
in
- TokenStream that will be filtered
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Method Detail
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incrementToken
public boolean incrementToken() throws java.io.IOException
Description copied from class:TokenStream
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriateAttributeImpl
s with the attributes of the next token.The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
andAttributeSource.getAttribute(Class)
, references to allAttributeImpl
s that this stream uses should be retrieved during instantiation.To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in
TokenStream.incrementToken()
.- Specified by:
incrementToken
in classTokenStream
- Returns:
- false for end of stream; true otherwise
- Throws:
java.io.IOException
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reset
public void reset() throws java.io.IOException
Description copied from class:TokenFilter
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
.Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.
If you override this method, always call
super.reset()
, otherwise some internal state will not be correctly reset (e.g.,Tokenizer
will throwIllegalStateException
on further usage).NOTE: The default implementation chains the call to the input TokenStream, so be sure to call
super.reset()
when overriding this method.- Overrides:
reset
in classTokenFilter
- Throws:
java.io.IOException
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unhyphenate
private void unhyphenate()
Writes the joined unhyphenated term
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