Lucene example source code file (Trec1MQReader.java)

This example Lucene source code file (Trec1MQReader.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, hashmap, hashmap, io, ioexception, qualityquery, qualityquery, string, string, trec1mqreader, trec1mqreader, util

The Lucene Trec1MQReader.java source code

/**
 * 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.
 */
package org.apache.lucene.benchmark.quality.trec;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;

import org.apache.lucene.benchmark.quality.QualityQuery;

/**
 * Read topics of TREC 1MQ track.
 * <p>
 * Expects this topic format -
 * <pre>
 *   qnum:qtext
 * </pre>
 * Comment lines starting with '#' are ignored.
 * <p>
 * All topics will have a single name value pair.
 */
public class Trec1MQReader {

  private String name;
  
  /**
   *  Constructor for Trec's 1MQ TopicsReader
   *  @param name name of name-value pair to set for all queries.
   */
  public Trec1MQReader(String name) {
    super();
    this.name = name;
  }

  /**
   * Read quality queries from trec 1MQ format topics file.
   * @param reader where queries are read from.
   * @return the result quality queries.
   * @throws IOException if cannot read the queries.
   */
  public QualityQuery[] readQueries(BufferedReader reader) throws IOException {
    ArrayList<QualityQuery> res = new ArrayList();
    String line;
    try {
      while (null!=(line=reader.readLine())) {
        line = line.trim();
        if (line.startsWith("#")) {
          continue;
        }
        // id
        int k = line.indexOf(":");
        String id = line.substring(0,k).trim();
        // qtext
        String qtext = line.substring(k+1).trim();
        // we got a topic!
        HashMap<String,String> fields = new HashMap();
        fields.put(name,qtext);
        //System.out.println("id: "+id+" qtext: "+qtext+"  line: "+line);
        QualityQuery topic = new QualityQuery(id,fields);
        res.add(topic);
      }
    } finally {
      reader.close();
    }
    // sort result array (by ID) 
    QualityQuery qq[] = res.toArray(new QualityQuery[0]);
    Arrays.sort(qq);
    return qq;
  }

}