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Lucene example source code file (ReutersQueryMaker.java)

This example Lucene source code file (ReutersQueryMaker.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lucene tags/keywords

arraylist, bank, exception, query, query, sony, spanfirstquery, spanfirstquery, spannearquery, spantermquery, spantermquery, string, term, term, util

The Lucene ReutersQueryMaker.java source code

package org.apache.lucene.benchmark.byTask.feeds;

/**
 * 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 org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.WildcardQuery;
import org.apache.lucene.search.spans.SpanFirstQuery;
import org.apache.lucene.search.spans.SpanNearQuery;
import org.apache.lucene.search.spans.SpanQuery;
import org.apache.lucene.search.spans.SpanTermQuery;
import org.apache.lucene.benchmark.byTask.tasks.NewAnalyzerTask;
import org.apache.lucene.util.Version;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;


/**
 * A QueryMaker that makes queries devised manually (by Grant Ingersoll) for
 * searching in the Reuters collection.
 */
public class ReutersQueryMaker extends AbstractQueryMaker implements QueryMaker {

  private static String [] STANDARD_QUERIES = {
    //Start with some short queries
    "Salomon", "Comex", "night trading", "Japan Sony",
    //Try some Phrase Queries
    "\"Sony Japan\"", "\"food needs\"~3",
    "\"World Bank\"^2 AND Nigeria", "\"World Bank\" -Nigeria",
    "\"Ford Credit\"~5",
    //Try some longer queries
    "airline Europe Canada destination",
    "Long term pressure by trade " +
    "ministers is necessary if the current Uruguay round of talks on " +
    "the General Agreement on Trade and Tariffs (GATT) is to " +
    "succeed"
  };
  
  private static Query[] getPrebuiltQueries(String field) {
    //  be wary of unanalyzed text
    return new Query[] {
        new SpanFirstQuery(new SpanTermQuery(new Term(field, "ford")), 5),
        new SpanNearQuery(new SpanQuery[]{new SpanTermQuery(new Term(field, "night")), new SpanTermQuery(new Term(field, "trading"))}, 4, false),
        new SpanNearQuery(new SpanQuery[]{new SpanFirstQuery(new SpanTermQuery(new Term(field, "ford")), 10), new SpanTermQuery(new Term(field, "credit"))}, 10, false),
        new WildcardQuery(new Term(field, "fo*")),
    };
  }
  
  /**
   * Parse the strings containing Lucene queries.
   *
   * @param qs array of strings containing query expressions
   * @param a  analyzer to use when parsing queries
   * @return array of Lucene queries
   */
  private static Query[] createQueries(List<Object> qs, Analyzer a) {
    QueryParser qp = new QueryParser(Version.LUCENE_CURRENT, DocMaker.BODY_FIELD, a);
    List<Object> queries = new ArrayList();
    for (int i = 0; i < qs.size(); i++)  {
      try {
        
        Object query = qs.get(i);
        Query q = null;
        if (query instanceof String) {
          q = qp.parse((String) query);
          
        } else if (query instanceof Query) {
          q = (Query) query;
          
        } else {
          System.err.println("Unsupported Query Type: " + query);
        }
        
        if (q != null) {
          queries.add(q);
        }
        
      } catch (Exception e)  {
        e.printStackTrace();
      }
    }
    
    return queries.toArray(new Query[0]);
  }
  
  @Override
  protected Query[] prepareQueries() throws Exception {
    // analyzer (default is standard analyzer)
    Analyzer anlzr= NewAnalyzerTask.createAnalyzer(config.get("analyzer",
    "org.apache.lucene.analysis.standard.StandardAnalyzer")); 
    
    List<Object> queryList = new ArrayList(20);
    queryList.addAll(Arrays.asList(STANDARD_QUERIES));
    queryList.addAll(Arrays.asList(getPrebuiltQueries(DocMaker.BODY_FIELD)));
    return createQueries(queryList, anlzr);
  }


  

}

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