org.apache.lucene.search.uhighlight

Class CustomUnifiedHighlighter

java.lang.Object

org.apache.lucene.search.uhighlight.UnifiedHighlighter

org.apache.lucene.search.uhighlight.CustomUnifiedHighlighter

public class CustomUnifiedHighlighter
extends org.apache.lucene.search.uhighlight.UnifiedHighlighter

Subclass of the UnifiedHighlighter that works for a single field in a single document. Uses a custom PassageFormatter. Accepts field content as a constructor argument, given that loadings field value can be done reading from _source field. Supports using different BreakIterator to break the text into fragments. Considers every distinct field value as a discrete passage for highlighting (unless the whole content needs to be highlighted). Supports both returning empty snippets and non highlighted snippets when no highlighting can be performed.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.uhighlight.UnifiedHighlighter

org.apache.lucene.search.uhighlight.UnifiedHighlighter.HighlightFlag, org.apache.lucene.search.uhighlight.UnifiedHighlighter.LimitedStoredFieldVisitor, org.apache.lucene.search.uhighlight.UnifiedHighlighter.OffsetSource

Field Summary

Fields inherited from class org.apache.lucene.search.uhighlight.UnifiedHighlighter

DEFAULT_CACHE_CHARS_THRESHOLD, DEFAULT_MAX_LENGTH, fieldInfos, indexAnalyzer, MULTIVAL_SEP_CHAR, searcher, ZERO_LEN_AUTOMATA_ARRAY

Constructor Summary

Constructors

Constructor and Description
CustomUnifiedHighlighter(org.apache.lucene.search.IndexSearcher searcher, org.apache.lucene.analysis.Analyzer analyzer, org.apache.lucene.search.uhighlight.PassageFormatter passageFormatter, java.text.BreakIterator breakIterator, java.lang.String fieldValue, boolean returnNonHighlightedSnippets) Creates a new instance of CustomUnifiedHighlighter

Method Summary

Modifier and Type	Method and Description
protected java.text.BreakIterator	getBreakIterator(java.lang.String field)
protected org.apache.lucene.search.uhighlight.PassageFormatter	getFormatter(java.lang.String field)
protected int	getMaxNoHighlightPassages(java.lang.String field)
Snippet[]	highlightField(java.lang.String field, org.apache.lucene.search.Query query, int docId, int maxPassages) Highlights terms extracted from the provided query within the content of the provided field name
protected java.util.List<java.lang.CharSequence[]>	loadFieldValues(java.lang.String[] fields, org.apache.lucene.search.DocIdSetIterator docIter, int cacheCharsThreshold)
protected java.util.Collection<org.apache.lucene.search.Query>	preMultiTermQueryRewrite(org.apache.lucene.search.Query query)
protected java.util.Collection<org.apache.lucene.search.Query>	preSpanQueryRewrite(org.apache.lucene.search.Query query)

Methods inherited from class org.apache.lucene.search.uhighlight.UnifiedHighlighter

extractTerms, filterExtractedTerms, getAutomata, getCacheFieldValCharsThreshold, getFieldHighlighter, getFieldInfo, getFieldMatcher, getFlags, getIndexAnalyzer, getIndexSearcher, getMaxLength, getOffsetSource, getOffsetStrategy, getOptimizedOffsetSource, getPhraseHelper, getScorer, highlight, highlight, highlightFields, highlightFields, highlightFields, highlightFieldsAsObjects, highlightWithoutSearcher, newLimitedStoredFieldsVisitor, requiresRewrite, setBreakIterator, setCacheFieldValCharsThreshold, setFieldMatcher, setFormatter, setHandleMultiTermQuery, setHighlightPhrasesStrictly, setMaxLength, setMaxNoHighlightPassages, setScorer, shouldHandleMultiTermQuery, shouldHighlightPhrasesStrictly, shouldPreferPassageRelevancyOverSpeed

Methods inherited from class java.lang.Object

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

Constructor Detail

CustomUnifiedHighlighter

public CustomUnifiedHighlighter(org.apache.lucene.search.IndexSearcher searcher,
                                org.apache.lucene.analysis.Analyzer analyzer,
                                org.apache.lucene.search.uhighlight.PassageFormatter passageFormatter,
                                @Nullable
                                java.text.BreakIterator breakIterator,
                                java.lang.String fieldValue,
                                boolean returnNonHighlightedSnippets)

Creates a new instance of CustomUnifiedHighlighter

Parameters:

analyzer - the analyzer used for the field at index time, used for multi term queries internally

passageFormatter - our own CustomPassageFormatter which generates snippets in forms of Snippet objects

breakIterator - the BreakIterator to use for dividing text into passages. If null BreakIterator.getSentenceInstance(Locale) is used.

fieldValue - the original field values as constructor argument, loaded from the _source field or the relevant stored field.

returnNonHighlightedSnippets - whether non highlighted snippets should be returned rather than empty snippets when no highlighting can be performed

Method Detail

highlightField

public Snippet[] highlightField(java.lang.String field,
                                org.apache.lucene.search.Query query,
                                int docId,
                                int maxPassages)
                         throws java.io.IOException

Highlights terms extracted from the provided query within the content of the provided field name

Throws:

java.io.IOException

loadFieldValues

protected java.util.List<java.lang.CharSequence[]> loadFieldValues(java.lang.String[] fields,
                                                                   org.apache.lucene.search.DocIdSetIterator docIter,
                                                                   int cacheCharsThreshold)
                                                            throws java.io.IOException

Overrides:

loadFieldValues in class org.apache.lucene.search.uhighlight.UnifiedHighlighter

Throws:

java.io.IOException

getBreakIterator

protected java.text.BreakIterator getBreakIterator(java.lang.String field)

Overrides:

getBreakIterator in class org.apache.lucene.search.uhighlight.UnifiedHighlighter

getFormatter

protected org.apache.lucene.search.uhighlight.PassageFormatter getFormatter(java.lang.String field)

Overrides:

getFormatter in class org.apache.lucene.search.uhighlight.UnifiedHighlighter

getMaxNoHighlightPassages

protected int getMaxNoHighlightPassages(java.lang.String field)

Overrides:

getMaxNoHighlightPassages in class org.apache.lucene.search.uhighlight.UnifiedHighlighter

preMultiTermQueryRewrite

protected java.util.Collection<org.apache.lucene.search.Query> preMultiTermQueryRewrite(org.apache.lucene.search.Query query)

Overrides:

preMultiTermQueryRewrite in class org.apache.lucene.search.uhighlight.UnifiedHighlighter

preSpanQueryRewrite

protected java.util.Collection<org.apache.lucene.search.Query> preSpanQueryRewrite(org.apache.lucene.search.Query query)

Overrides:

preSpanQueryRewrite in class org.apache.lucene.search.uhighlight.UnifiedHighlighter