Module org.apache.lucene.suggest

Package org.apache.lucene.search.suggest.document

Class CompletionQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.suggest.document.CompletionQuery

Direct Known Subclasses:

ContextQuery, PrefixCompletionQuery, RegexCompletionQuery

public abstract class CompletionQuery
extends Query

Abstract Query that match documents containing terms with a specified prefix filtered by BitsProducer. This should be used to query against any SuggestFields or ContextSuggestFields of documents.

Use SuggestIndexSearcher.suggest(CompletionQuery, int, boolean) to execute any query that provides a concrete implementation of this query. Example below shows using this query to retrieve the top 5 documents.

  SuggestIndexSearcher searcher = new SuggestIndexSearcher(reader);
  TopSuggestDocs suggestDocs = searcher.suggest(query, 5);
 

This query rewrites to an appropriate CompletionQuery depending on the type (SuggestField or ContextSuggestField) of the field the query is run against.

Field Summary

Fields

Modifier and Type	Field	Description
private final BitsProducer	filter	BitsProducer which is used to filter the document scope.
private final Term	term	Term to query against

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CompletionQuery(Term term, BitsProducer filter)	Creates a base Completion query against a term with a filter to scope the documents

Method Summary

Modifier and Type	Method	Description
String	getField()	Returns the field name this query should be run against
BitsProducer	getFilter()	Returns a BitsProducer.
Term	getTerm()	Returns the term to be queried against
Query	rewrite(IndexSearcher indexSearcher)	Expert: called to re-write queries into primitive queries.
String	toString(String field)	Prints a query to a string, with field assumed to be the default field and omitted.
private void	validate(String termText)

Methods inherited from class org.apache.lucene.search.Query

classHash, createWeight, equals, hashCode, rewrite, sameClassAs, toString, visit

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

term

private final Term term

Term to query against

filter

private final BitsProducer filter

BitsProducer which is used to filter the document scope.

Constructor Details

CompletionQuery

protected CompletionQuery(Term term,
 BitsProducer filter)

Creates a base Completion query against a term with a filter to scope the documents

Method Details

getFilter

public BitsProducer getFilter()

Returns a BitsProducer. Only suggestions matching the returned bits will be returned.

getField

public String getField()

Returns the field name this query should be run against

getTerm

public Term getTerm()

Returns the term to be queried against

rewrite

public Query rewrite(IndexSearcher indexSearcher)
              throws IOException

Description copied from class: Query

Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

Callers are expected to call rewrite multiple times if necessary, until the rewritten query is the same as the original query.

The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.

However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.

Overrides:

rewrite in class Query

Throws:

IOException

See Also:

• IndexSearcher.rewrite(Query)

toString

public String toString(String field)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

Specified by:

toString in class Query

validate

private void validate(String termText)