Package org.apache.lucene.search.spans

Class SpanMultiTermQueryWrapper<Q extends MultiTermQuery>

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.spans.SpanQuery

org.apache.lucene.search.spans.SpanMultiTermQueryWrapper<Q>

public class SpanMultiTermQueryWrapper<Q extends MultiTermQuery>
extends SpanQuery

Wraps any MultiTermQuery as a SpanQuery, so it can be nested within other SpanQuery classes.

The query is rewritten by default to a SpanOrQuery containing the expanded terms, but this can be customized.

Example:

 
 WildcardQuery wildcard = new WildcardQuery(new Term("field", "bro?n"));
 SpanQuery spanWildcard = new SpanMultiTermQueryWrapper<WildcardQuery>(wildcard);
 // do something with spanWildcard, such as use it in a SpanFirstQuery
 
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SpanMultiTermQueryWrapper.SpanRewriteMethod	Abstract class that defines how the query is rewritten.
static class	SpanMultiTermQueryWrapper.TopTermsSpanBooleanQueryRewrite	A rewrite method that first translates each term into a SpanTermQuery in a BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query.

Field Summary

Fields

Modifier and Type	Field	Description
protected Q	query
static SpanMultiTermQueryWrapper.SpanRewriteMethod	SCORING_SPAN_QUERY_REWRITE	A rewrite method that first translates each term into a SpanTermQuery in a BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query.

Constructor Summary

Constructors

Constructor	Description
SpanMultiTermQueryWrapper(Q query)	Create a new SpanMultiTermQueryWrapper.

Method Summary

Modifier and Type	Method	Description
SpanWeight	createWeight(IndexSearcher searcher, boolean needsScores, float boost)	Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object other)	Override and implement query instance equivalence properly in a subclass.
String	getField()	Returns the name of the field matched by this query.
SpanMultiTermQueryWrapper.SpanRewriteMethod	getRewriteMethod()	Expert: returns the rewriteMethod
Query	getWrappedQuery()	Returns the wrapped query
int	hashCode()	Override and implement query hash code properly in a subclass.
Query	rewrite(IndexReader reader)	Expert: called to re-write queries into primitive queries.
void	setRewriteMethod(SpanMultiTermQueryWrapper.SpanRewriteMethod rewriteMethod)	Expert: sets the rewrite method.
String	toString(String field)	Prints a query to a string, with field assumed to be the default field and omitted.

Methods inherited from class org.apache.lucene.search.spans.SpanQuery

getTermContexts, getTermContexts

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

classHash, sameClassAs, toString

Methods inherited from class java.lang.Object

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

Field Detail

query

protected final Q extends MultiTermQuery query

SCORING_SPAN_QUERY_REWRITE

public static final SpanMultiTermQueryWrapper.SpanRewriteMethod SCORING_SPAN_QUERY_REWRITE

A rewrite method that first translates each term into a SpanTermQuery in a BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query.

See Also:

setRewriteMethod(org.apache.lucene.search.spans.SpanMultiTermQueryWrapper.SpanRewriteMethod)

Constructor Detail

SpanMultiTermQueryWrapper

public SpanMultiTermQueryWrapper(Q query)

Create a new SpanMultiTermQueryWrapper.

Parameters:

query - Query to wrap.

Method Detail

getRewriteMethod

public final SpanMultiTermQueryWrapper.SpanRewriteMethod getRewriteMethod()

Expert: returns the rewriteMethod

setRewriteMethod

public final void setRewriteMethod(SpanMultiTermQueryWrapper.SpanRewriteMethod rewriteMethod)

Expert: sets the rewrite method. This only makes sense to be a span rewrite method.

getField

public String getField()

Description copied from class: SpanQuery

Returns the name of the field matched by this query.

Specified by:

getField in class SpanQuery

createWeight

public SpanWeight createWeight(IndexSearcher searcher,
                               boolean needsScores,
                               float boost)
                        throws IOException

Description copied from class: Query

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Specified by:

createWeight in class SpanQuery

needsScores - True if document scores (Scorer.score()) are needed.

boost - The boost that is propagated by the parent queries.

Throws:

IOException

getWrappedQuery

public Query getWrappedQuery()

Returns the wrapped 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

rewrite

public Query rewrite(IndexReader reader)
              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.

Overrides:

rewrite in class Query

Throws:

IOException

hashCode

public int hashCode()

Description copied from class: Query

Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.

Specified by:

hashCode in class Query

See Also:

Query.equals(Object)

equals

public boolean equals(Object other)

Description copied from class: Query

Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly. Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical that other instance. Utility methods are provided for certain repetitive code.

Specified by:

equals in class Query

See Also:

Query.sameClassAs(Object), Query.classHash()