/*
* Hibernate Search, full-text search for your domain model
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.search.query.engine.impl;
import java.util.Collections;
import java.util.List;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.BooleanClause.Occur;
/**
* Internal representation for a set of filters to be applied on a query.
*
* @author Sanne Grinovero
*/
public final class QueryFilters {
public static final QueryFilters EMPTY_FILTERSET = new QueryFilters();
private final List<Query> filterQueries;
private QueryFilters() {
filterQueries = Collections.emptyList();
}
public QueryFilters(List<Query> filterQueries) {
this.filterQueries = filterQueries;
}
/**
* Will wrap the passed Query into a BooleanQuery to apply all filters as boolean clauses.
* Returns the unmodified (same instance) of the input if there are no filters to be applied.
* @param queryToFilter The query to be filtered.
* @return The filtered query.
*/
public Query filterOrPassthrough(Query queryToFilter) {
if ( isEmpty() ) {
return queryToFilter;
}
else {
BooleanQuery.Builder boolQueryBuilder = new BooleanQuery.Builder();
boolQueryBuilder.add( queryToFilter, Occur.MUST );
for ( Query bc : filterQueries ) {
boolQueryBuilder.add( bc, BooleanClause.Occur.FILTER );
}
return boolQueryBuilder.build();
}
}
/**
* @return lists all Lucene query instances which should be applied as filters
*/
public List<Query> getFilterQueries() {
return filterQueries;
}
/**
* @return <tt>true</tt> if this contains to filters to be applied.
*/
public boolean isEmpty() {
return filterQueries.isEmpty();
}
}