com.sindicetech.siren.qparser.keyword.builders.BooleanQueryNodeBuilder.java Source code

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Here is the source code for com.sindicetech.siren.qparser.keyword.builders.BooleanQueryNodeBuilder.java

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/**
 * Copyright (c) 2014, Sindice Limited. All Rights Reserved.
 *
 * This file is part of the SIREn project.
 *
 * SIREn is a free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * SIREn is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package com.sindicetech.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 com.sindicetech.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;

    }

}