org.elasticsearch.index.query.xcontent.DisMaxQueryParser Maven / Gradle / Ivy

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/*
 * Licensed to Elastic Search and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Elastic Search 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.
 */

package org.elasticsearch.index.query.xcontent;

import org.apache.lucene.search.DisjunctionMaxQuery;
import org.apache.lucene.search.Query;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.AbstractIndexComponent;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.query.QueryParsingException;
import org.elasticsearch.index.settings.IndexSettings;

import java.io.IOException;
import java.util.List;

import static org.elasticsearch.common.collect.Lists.*;

/**
 * @author kimchy (shay.banon)
 */
public class DisMaxQueryParser extends AbstractIndexComponent implements XContentQueryParser {

    public static final String NAME = "dis_max";

    @Inject public DisMaxQueryParser(Index index, @IndexSettings Settings settings) {
        super(index, settings);
    }

    @Override public String[] names() {
        return new String[]{NAME, Strings.toCamelCase(NAME)};
    }

    @Override public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
        XContentParser parser = parseContext.parser();

        float boost = 1.0f;
        float tieBreaker = 0.0f;

        List queries = newArrayList();

        String currentFieldName = null;
        XContentParser.Token token;
        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
            if (token == XContentParser.Token.FIELD_NAME) {
                currentFieldName = parser.currentName();
            } else if (token == XContentParser.Token.START_OBJECT) {
                if ("queries".equals(currentFieldName)) {
                    queries.add(parseContext.parseInnerQuery());
                }
            } else if (token == XContentParser.Token.START_ARRAY) {
                if ("queries".equals(currentFieldName)) {
                    while (token != XContentParser.Token.END_ARRAY) {
                        queries.add(parseContext.parseInnerQuery());
                        token = parser.nextToken();
                    }
                }
            } else {
                if ("boost".equals(currentFieldName)) {
                    boost = parser.floatValue();
                } else if ("tie_breaker".equals(currentFieldName) || "tieBreaker".equals(currentFieldName)) {
                    tieBreaker = parser.floatValue();
                }
            }
        }

        DisjunctionMaxQuery query = new DisjunctionMaxQuery(queries, tieBreaker);
        query.setBoost(boost);
        return query;
    }
}