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

Method Summary

Modifier and Type	Method and Description
SpanWeight	createWeight(IndexSearcher searcher, boolean needsScores) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object obj)
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()
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

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)
                        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()) or match frequencies (Scorer.freq()) are needed.

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()

Overrides:

hashCode in class Query

equals

public boolean equals(Object obj)

Overrides:

equals in class Query