/**
* Copyright 2014 National University of Ireland, Galway.
*
* This file is part of the SIREn project. Project and contact information:
*
* https://github.com/rdelbru/SIREn
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.sindice.siren.qparser.keyword.builders;
import java.util.List;
import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
import org.apache.lucene.queryparser.flexible.core.builders.QueryTreeBuilder;
import org.apache.lucene.queryparser.flexible.core.messages.QueryParserMessages;
import org.apache.lucene.queryparser.flexible.core.nodes.BooleanQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.ModifierQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode;
import org.apache.lucene.queryparser.flexible.messages.MessageImpl;
import org.apache.lucene.queryparser.flexible.standard.builders.StandardQueryBuilder;
import org.apache.lucene.queryparser.flexible.standard.parser.EscapeQuerySyntaxImpl;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.BooleanQuery.TooManyClauses;
import org.apache.lucene.search.Query;
import org.sindice.siren.qparser.keyword.nodes.DatatypeQueryNode;
/**
* Builds a {@link BooleanQuery} object from a {@link BooleanQueryNode} object.
*
* <p>
*
* Every children in the {@link BooleanQueryNode} object must be already tagged
* using {@link QueryTreeBuilder#QUERY_TREE_BUILDER_TAGID} with a {@link Query}
* object. It takes in consideration if the children is a
* {@link ModifierQueryNode} to define the {@link BooleanClause}.
*/
public class BooleanQueryNodeBuilder implements StandardQueryBuilder {
public BooleanQueryNodeBuilder() {
// empty constructor
}
public Query build(final QueryNode queryNode) throws QueryNodeException {
final BooleanQueryNode booleanNode = (BooleanQueryNode) queryNode;
final BooleanQuery bQuery = new BooleanQuery();
final List<QueryNode> children = booleanNode.getChildren();
if (children != null) {
for (final QueryNode child : children) {
final Object obj = child.getTag(QueryTreeBuilder.QUERY_TREE_BUILDER_TAGID);
if (obj != null) {
final Query query = (Query) obj;
try {
final QueryNode mod;
if (child instanceof DatatypeQueryNode) {
mod = ((DatatypeQueryNode) child).getChild();
} else {
mod = child;
}
bQuery.add(query, getModifierValue(mod));
} catch (final TooManyClauses ex) {
throw new QueryNodeException(new MessageImpl(
QueryParserMessages.TOO_MANY_BOOLEAN_CLAUSES, BooleanQuery
.getMaxClauseCount(), queryNode
.toQueryString(new EscapeQuerySyntaxImpl())), ex);
}
}
}
}
return bQuery;
}
private static BooleanClause.Occur getModifierValue(final QueryNode node) {
if (node instanceof ModifierQueryNode) {
final ModifierQueryNode mNode = ((ModifierQueryNode) node);
switch (mNode.getModifier()) {
case MOD_REQ:
return BooleanClause.Occur.MUST;
case MOD_NOT:
return BooleanClause.Occur.MUST_NOT;
case MOD_NONE:
return BooleanClause.Occur.SHOULD;
}
}
return BooleanClause.Occur.SHOULD;
}
}