Lucene - Indexing Operations

Lucene - Query Programming

Lucene - Analysis

Lucene - Resources

Lucene - IndexSearcher Class

Quiz

This class acts as a core component which reads/searches indexes during the searching process.

Class Declaration

Following is the declaration for org.apache.lucene.search.IndexSearcher class −

public class IndexSearcher
   extends Searcher

Class Fields

Following table shows the class fields for IndexSearcher −

S.No.	Field & Description
1	protected final List<LeafReaderContext> leafContexts
2	protected final IndexReaderContext readerContext

Class Constructors

Following table shows the constructors for IndexSearcher −

S.No.	Field & Description
1	IndexSearcher(IndexReader r) Creates a searcher searching the provided index.
2	IndexSearcher(IndexReaderContext context) Creates a searcher searching the provided top-level IndexReaderContext.
3	IndexSearcher(IndexReaderContext context, Executor executor) Creates a searcher searching the provided top-level IndexReaderContext.
4	IndexSearcher(IndexReader r, Executor executor) Runs searches for each segment separately, using the provided Executor.

Class Methods

S.No.	Method & Description
1	CollectionStatistics collectionStatistics(String field) Returns CollectionStatistics for a field, or null if the field does not exist (has no indexed terms)
2	int count(Query query) Count how many documents match the given query.
3	Weight createWeight(Query query, ScoreMode scoreMode, float boost) Creates a Weight for the given query, potentially adding caching if possible and configured.
4	Explanation explain(Query query, int doc) Returns an Explanation that describes how doc scored against query.
5	protected Explanation explain(Weight weight, int doc) Expert: low-level implementation method Returns an Explanation that describes how doc scored against weight.
6	static QueryCache getDefaultQueryCache() Expert: Get the default QueryCache or null if the cache is disabled.
7	static QueryCachingPolicy getDefaultQueryCachingPolicy() Expert: Get the default QueryCachingPolicy.
8	static Similarity getDefaultSimilarity() Expert: returns a default Similarity instance.
9	IndexReader getIndexReader() Return the IndexReader this searches.
10	List<LeafReaderContext> getLeafContexts() Expert: returns leaf contexts associated with this searcher.
11	static int getMaxClauseCount() Return the maximum number of clauses permitted, 1024 by default.
12	QueryCache getQueryCache() Return the query cache of this IndexSearcher.
13	QueryCachingPolicy getQueryCachingPolicy() Return the query cache of this IndexSearcher.
14	Similarity getSimilarity() Expert: Get the Similarity to use to compute scores.
15	final IndexSearcher.LeafSlice[] getSlices() Returns the leaf slices used for concurrent searching.
16	TaskExecutor getTaskExecutor() Returns the TaskExecutor that this searcher relies on to execute concurrent operations.
17	QueryTimeout getTimeout() Get the configured QueryTimeout for all searches that run through this IndexSearcher, or null if not set.
18	IndexReaderContext getTopReaderContext() Returns this searcher's top-level IndexReaderContext.
19	Query rewrite(Query original) Expert: called to re-write queries into primitive queries.
20	protected void search(IndexSearcher.LeafReaderContextPartition[] partitions, Weight weight, Collector collector) Lower-level search API.
21	TopDocs search(Query query, int n) Finds the top n hits for query.
22	TopFieldDocs search(Query query, int n, Sort sort) Search implementation with arbitrary sorting.
23	TopFieldDocs search(Query query, int n, Sort sort, boolean doDocScores) Search implementation with arbitrary sorting, plus control over whether hit scores and max score should be computed.
24	void search(Query query, Collector collector) Deprecated. This method is being deprecated in favor of search(Query, CollectorManager) due to its support for concurrency in IndexSearcher.
25	<C extends Collector,T> T search(Query query, CollectorManager<C,T> collectorManager) Lower-level search API.
26	TopDocs searchAfter(ScoreDoc after, Query query, int numHits) Finds the top n hits for query where all results are after a previous result (after).
27	TopDocs searchAfter(ScoreDoc after, Query query, int n, Sort sort) Finds the top n hits for query where all results are after a previous result (after).
28	TopFieldDocs searchAfter(ScoreDoc after, Query query, int numHits, Sort sort, boolean doDocScores) Finds the top n hits for query where all results are after a previous result (after), allowing control over whether hit scores and max score should be computed.
29	protected void searchLeaf(LeafReaderContext ctx, int minDocId, int maxDocId, Weight weight, Collector collector) Lower-level search API
30	static void setDefaultQueryCache(QueryCache defaultQueryCache) Expert: set the default QueryCache instance.
31	static void setDefaultQueryCachingPolicy(QueryCachingPolicy defaultQueryCachingPolicy) Expert: set the default QueryCachingPolicy instance.
32	static void setMaxClauseCount(int value) Set the maximum number of clauses permitted per Query.
33	void setQueryCache(QueryCache queryCache) Set the QueryCache to use when scores are not needed.
34	void setQueryCachingPolicy(QueryCachingPolicy queryCachingPolicy) Set the QueryCachingPolicy to use for query caching.
35	void setSimilarity(Similarity similarity) Expert: Set the Similarity implementation used by this IndexSearcher.
36	void setTimeout(QueryTimeout queryTimeout) Set a QueryTimeout for all searches that run through this IndexSearcher.
37	protected IndexSearcher.LeafSlice[] slices(List<LeafReaderContext> leaves) Expert: Creates an array of leaf slices each holding a subset of the given leaves.
38	static IndexSearcher.LeafSlice[] slices(List<LeafReaderContext> leaves, int maxDocsPerSlice, int maxSegmentsPerSlice, boolean allowSegmentPartitions) Static method to segregate LeafReaderContexts amongst multiple slices.
39	StoredFields storedFields() Returns a StoredFields reader for the stored fields of this index.
40	TermStatistics termStatistics(Term term, int docFreq, long totalTermFreq) Returns TermStatistics for a term.
41	boolean timedOut() Returns true if any search hit the timeout.
42	String toString() Returns string representation.

Methods Inherited

This class inherits methods from the following classes −

org.apache.lucene.search.Searcher
java.lang.Object

lucene_searching_classes.htm

Print Page