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

Modifier and Type	Field and Description
static char	MULTIVAL_SEP_CHAR

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

DEFAULT_CACHE_CHARS_THRESHOLD, DEFAULT_MAX_LENGTH, fieldInfos, indexAnalyzer, 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.UnifiedHighlighter.OffsetSource offsetSource, org.apache.lucene.search.uhighlight.PassageFormatter passageFormatter, java.util.Locale breakIteratorLocale, java.text.BreakIterator breakIterator, java.lang.String fieldValue, int noMatchSize) 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.FieldHighlighter	getFieldHighlighter(java.lang.String field, org.apache.lucene.search.Query query, java.util.Set<org.apache.lucene.index.Term> allTerms, int maxPassages)
protected org.apache.lucene.search.uhighlight.PassageFormatter	getFormatter(java.lang.String field)
protected org.apache.lucene.search.uhighlight.UnifiedHighlighter.OffsetSource	getOffsetSource(java.lang.String field) Forces the offset source for this highlighter
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, getFieldInfo, getFieldMatcher, getFlags, getIndexAnalyzer, getIndexSearcher, getMaxLength, getMaxNoHighlightPassages, 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

Field Detail

MULTIVAL_SEP_CHAR

public static final char MULTIVAL_SEP_CHAR

See Also:

Constant Field Values

Constructor Detail

CustomUnifiedHighlighter

public CustomUnifiedHighlighter(org.apache.lucene.search.IndexSearcher searcher,
                                org.apache.lucene.analysis.Analyzer analyzer,
                                org.apache.lucene.search.uhighlight.UnifiedHighlighter.OffsetSource offsetSource,
                                org.apache.lucene.search.uhighlight.PassageFormatter passageFormatter,
                                @Nullable
                                java.util.Locale breakIteratorLocale,
                                @Nullable
                                java.text.BreakIterator breakIterator,
                                java.lang.String fieldValue,
                                int noMatchSize)

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.

offsetSource - the OffsetSource to used for offsets retrieval.

breakIteratorLocale - the Locale to use for dividing text into passages. If null Locale.ROOT is used.

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

fieldValue - the original field values delimited by MULTIVAL_SEP_CHAR.

noMatchSize - The size of the text that should be returned 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

getFieldHighlighter

protected org.apache.lucene.search.uhighlight.FieldHighlighter getFieldHighlighter(java.lang.String field,
                                                                                   org.apache.lucene.search.Query query,
                                                                                   java.util.Set<org.apache.lucene.index.Term> allTerms,
                                                                                   int maxPassages)

Overrides:

getFieldHighlighter 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

getOffsetSource

protected org.apache.lucene.search.uhighlight.UnifiedHighlighter.OffsetSource getOffsetSource(java.lang.String field)

Forces the offset source for this highlighter

Overrides:

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