org.apache.lucene.search.vectorhighlight

Class FastVectorHighlighter

java.lang.Object

org.apache.lucene.search.vectorhighlight.FastVectorHighlighter

public class FastVectorHighlighter
extends Object

Another highlighter implementation.

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	DEFAULT_FIELD_MATCH
static boolean	DEFAULT_PHRASE_HIGHLIGHT
protected boolean	fieldMatch
protected boolean	phraseHighlight

Constructor Summary

Constructors

Constructor and Description
FastVectorHighlighter() the default constructor.
FastVectorHighlighter(boolean phraseHighlight, boolean fieldMatch) a constructor.
FastVectorHighlighter(boolean phraseHighlight, boolean fieldMatch, FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder) a constructor.

Method Summary

Modifier and Type	Method and Description
String	getBestFragment(FieldQuery fieldQuery, IndexReader reader, int docId, String fieldName, int fragCharSize) return the best fragment.
String	getBestFragment(FieldQuery fieldQuery, IndexReader reader, int docId, String fieldName, int fragCharSize, FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder, String[] preTags, String[] postTags, Encoder encoder) return the best fragment.
String[]	getBestFragments(FieldQuery fieldQuery, IndexReader reader, int docId, String fieldName, int fragCharSize, int maxNumFragments) return the best fragments.
String[]	getBestFragments(FieldQuery fieldQuery, IndexReader reader, int docId, String fieldName, int fragCharSize, int maxNumFragments, FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder, String[] preTags, String[] postTags, Encoder encoder) return the best fragments.
String[]	getBestFragments(FieldQuery fieldQuery, IndexReader reader, int docId, String storedField, Set<String> matchedFields, int fragCharSize, int maxNumFragments, FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder, String[] preTags, String[] postTags, Encoder encoder) Return the best fragments.
FieldQuery	getFieldQuery(Query query) create a FieldQuery object.
FieldQuery	getFieldQuery(Query query, IndexReader reader) create a FieldQuery object.
int	getPhraseLimit()
boolean	isFieldMatch() return whether fieldMatch or not.
boolean	isPhraseHighlight() return whether phraseHighlight or not.
void	setPhraseLimit(int phraseLimit) set the maximum number of phrases to analyze when searching for the highest-scoring phrase.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PHRASE_HIGHLIGHT

public static final boolean DEFAULT_PHRASE_HIGHLIGHT

See Also:

Constant Field Values

DEFAULT_FIELD_MATCH

public static final boolean DEFAULT_FIELD_MATCH

See Also:

Constant Field Values

phraseHighlight

protected final boolean phraseHighlight

fieldMatch

protected final boolean fieldMatch

Constructor Detail

FastVectorHighlighter

public FastVectorHighlighter()

the default constructor.

FastVectorHighlighter

public FastVectorHighlighter(boolean phraseHighlight,
                             boolean fieldMatch)

a constructor. Using SimpleFragListBuilder and ScoreOrderFragmentsBuilder.

Parameters:

phraseHighlight - true or false for phrase highlighting

fieldMatch - true of false for field matching

FastVectorHighlighter

public FastVectorHighlighter(boolean phraseHighlight,
                             boolean fieldMatch,
                             FragListBuilder fragListBuilder,
                             FragmentsBuilder fragmentsBuilder)

a constructor. A FragListBuilder and a FragmentsBuilder can be specified (plugins).

Parameters:

phraseHighlight - true of false for phrase highlighting

fieldMatch - true of false for field matching

fragListBuilder - an instance of FragListBuilder

fragmentsBuilder - an instance of FragmentsBuilder

Method Detail

getFieldQuery

public FieldQuery getFieldQuery(Query query)

create a FieldQuery object.

Parameters:

query - a query

Returns:

the created FieldQuery object

getFieldQuery

public FieldQuery getFieldQuery(Query query,
                                IndexReader reader)
                         throws IOException

create a FieldQuery object.

Parameters:

query - a query

Returns:

the created FieldQuery object

Throws:

IOException

getBestFragment

public final String getBestFragment(FieldQuery fieldQuery,
                                    IndexReader reader,
                                    int docId,
                                    String fieldName,
                                    int fragCharSize)
                             throws IOException

return the best fragment.

Parameters:

fieldQuery - FieldQuery object

reader - IndexReader of the index

docId - document id to be highlighted

fieldName - field of the document to be highlighted

fragCharSize - the length (number of chars) of a fragment

Returns:

the best fragment (snippet) string

Throws:

IOException - If there is a low-level I/O error

getBestFragments

public final String[] getBestFragments(FieldQuery fieldQuery,
                                       IndexReader reader,
                                       int docId,
                                       String fieldName,
                                       int fragCharSize,
                                       int maxNumFragments)
                                throws IOException

return the best fragments.

Parameters:

fieldQuery - FieldQuery object

reader - IndexReader of the index

docId - document id to be highlighted

fieldName - field of the document to be highlighted

fragCharSize - the length (number of chars) of a fragment

maxNumFragments - maximum number of fragments

Returns:

created fragments or null when no fragments created. size of the array can be less than maxNumFragments

Throws:

IOException - If there is a low-level I/O error

getBestFragment

public final String getBestFragment(FieldQuery fieldQuery,
                                    IndexReader reader,
                                    int docId,
                                    String fieldName,
                                    int fragCharSize,
                                    FragListBuilder fragListBuilder,
                                    FragmentsBuilder fragmentsBuilder,
                                    String[] preTags,
                                    String[] postTags,
                                    Encoder encoder)
                             throws IOException

return the best fragment.

Parameters:

fieldQuery - FieldQuery object

reader - IndexReader of the index

docId - document id to be highlighted

fieldName - field of the document to be highlighted

fragCharSize - the length (number of chars) of a fragment

fragListBuilder - FragListBuilder object

fragmentsBuilder - FragmentsBuilder object

preTags - pre-tags to be used to highlight terms

postTags - post-tags to be used to highlight terms

encoder - an encoder that generates encoded text

Returns:

the best fragment (snippet) string

Throws:

IOException - If there is a low-level I/O error

getBestFragments

public final String[] getBestFragments(FieldQuery fieldQuery,
                                       IndexReader reader,
                                       int docId,
                                       String fieldName,
                                       int fragCharSize,
                                       int maxNumFragments,
                                       FragListBuilder fragListBuilder,
                                       FragmentsBuilder fragmentsBuilder,
                                       String[] preTags,
                                       String[] postTags,
                                       Encoder encoder)
                                throws IOException

return the best fragments.

Parameters:

fieldQuery - FieldQuery object

reader - IndexReader of the index

docId - document id to be highlighted

fieldName - field of the document to be highlighted

fragCharSize - the length (number of chars) of a fragment

maxNumFragments - maximum number of fragments

fragListBuilder - FragListBuilder object

fragmentsBuilder - FragmentsBuilder object

preTags - pre-tags to be used to highlight terms

postTags - post-tags to be used to highlight terms

encoder - an encoder that generates encoded text

Returns:

created fragments or null when no fragments created. size of the array can be less than maxNumFragments

Throws:

IOException - If there is a low-level I/O error

getBestFragments

public final String[] getBestFragments(FieldQuery fieldQuery,
                                       IndexReader reader,
                                       int docId,
                                       String storedField,
                                       Set<String> matchedFields,
                                       int fragCharSize,
                                       int maxNumFragments,
                                       FragListBuilder fragListBuilder,
                                       FragmentsBuilder fragmentsBuilder,
                                       String[] preTags,
                                       String[] postTags,
                                       Encoder encoder)
                                throws IOException

Return the best fragments. Matches are scanned from matchedFields and turned into fragments against storedField. The highlighting may not make sense if matchedFields has matches with offsets that don't correspond features in storedField. It will outright throw a StringIndexOutOfBoundsException if matchedFields produces offsets outside of storedField. As such it is advisable that all matchedFields share the same source as storedField or are at least a prefix of it.

Parameters:

fieldQuery - FieldQuery object

reader - IndexReader of the index

docId - document id to be highlighted

storedField - field of the document that stores the text

matchedFields - fields of the document to scan for matches

fragCharSize - the length (number of chars) of a fragment

maxNumFragments - maximum number of fragments

fragListBuilder - FragListBuilder object

fragmentsBuilder - FragmentsBuilder object

preTags - pre-tags to be used to highlight terms

postTags - post-tags to be used to highlight terms

encoder - an encoder that generates encoded text

Returns:

created fragments or null when no fragments created. size of the array can be less than maxNumFragments

Throws:

IOException - If there is a low-level I/O error

isPhraseHighlight

public boolean isPhraseHighlight()

return whether phraseHighlight or not.

Returns:

whether phraseHighlight or not

isFieldMatch

public boolean isFieldMatch()

return whether fieldMatch or not.

Returns:

whether fieldMatch or not

getPhraseLimit

public int getPhraseLimit()

Returns:

the maximum number of phrases to analyze when searching for the highest-scoring phrase.

setPhraseLimit

public void setPhraseLimit(int phraseLimit)

set the maximum number of phrases to analyze when searching for the highest-scoring phrase. The default is unlimited (Integer.MAX_VALUE).