org.apache.solr.search.federated.DJoinQParserPlugin.java Source code

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Here is the source code for org.apache.solr.search.federated.DJoinQParserPlugin.java

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package org.apache.solr.search.federated;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import java.io.IOException;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.TopDocsCollector;
import org.apache.lucene.search.TopFieldCollector;
import org.apache.lucene.search.TopScoreDocCollector;
import org.apache.lucene.search.Weight;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.handler.component.MergeStrategy;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.search.QParser;
import org.apache.solr.search.QParserPlugin;
import org.apache.solr.search.RankQuery;
import org.apache.solr.search.SolrIndexSearcher.QueryCommand;
import org.apache.solr.search.SyntaxError;

public class DJoinQParserPlugin extends QParserPlugin {

    @Override
    @SuppressWarnings("rawtypes")
    public void init(NamedList args) {
    }

    @Override
    public QParser createParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
        return new QParser(qstr, localParams, params, req) {

            @Override
            public Query parse() throws SyntaxError {
                return new RankQuery() {

                    private Query mainQuery;

                    @Override
                    @SuppressWarnings("rawtypes")
                    public TopDocsCollector getTopDocsCollector(int len, QueryCommand cmd, IndexSearcher searcher)
                            throws IOException {
                        Sort sort = cmd.getSort();
                        if (sort == null) {
                            return TopScoreDocCollector.create(len, false);
                        } else {
                            return TopFieldCollector.create(sort.rewrite(searcher), len, false, true, true, false);
                        }
                    }

                    @Override
                    public MergeStrategy getMergeStrategy() {
                        return new DJoinMergeStrategy();
                    }

                    @Override
                    public RankQuery wrap(Query mainQuery) {
                        this.mainQuery = mainQuery;
                        return this;
                    }

                    @Override
                    public Query rewrite(IndexReader reader) throws IOException {
                        return mainQuery.rewrite(reader);
                    }

                    @Override
                    public Weight createWeight(IndexSearcher searcher) throws IOException {
                        return mainQuery.createWeight(searcher);
                    }

                };
            }

        };
    }

}