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>

All Implemented Interfaces:

Cloneable

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
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
boolean	equals(Object obj)
String	getField() Returns the name of the field matched by this query.
SpanMultiTermQueryWrapper.SpanRewriteMethod	getRewriteMethod() Expert: returns the rewriteMethod
Spans	getSpans(AtomicReaderContext context, Bits acceptDocs, Map<Term,TermContext> termContexts) Expert: Returns the matches for this query in an index.
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

createWeight

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

clone, extractTerms, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

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.

NOTE: This will call MultiTermQuery.setRewriteMethod(MultiTermQuery.RewriteMethod) on the wrapped query, changing its rewrite method to a suitable one for spans. Be sure to not change the rewrite method on the wrapped query afterwards! Doing so will throw UnsupportedOperationException on rewriting this query!

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.

getSpans

public Spans getSpans(AtomicReaderContext context,
                      Bits acceptDocs,
                      Map<Term,TermContext> termContexts)
               throws IOException

Description copied from class: SpanQuery

Expert: Returns the matches for this query in an index. Used internally to search for spans.

Specified by:

getSpans in class SpanQuery

Throws:

IOException

getField

public String getField()

Description copied from class: SpanQuery

Returns the name of the field matched by this query.

Note that this may return null if the query matches no terms.

Specified by:

getField in class SpanQuery

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