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Lucene example source code file (FileBasedQueryMaker.java)

This example Lucene source code file (FileBasedQueryMaker.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

abstractquerymaker, arraylist, bufferedreader, bufferedreader, exception, file, file, filebasedquerymaker, filereader, inputstream, inputstreamreader, io, reader, string, string, util

The Lucene FileBasedQueryMaker.java source code

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

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.Query;
import org.apache.lucene.benchmark.byTask.tasks.NewAnalyzerTask;
import org.apache.lucene.util.Version;

import java.io.*;
import java.util.ArrayList;
import java.util.List;

/**
 * Copyright 2004 The Apache Software Foundation
 * <p/>
 * Licensed 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
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * 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.
 */

/**
 * Create queries from a FileReader.  One per line, pass them through the
 * QueryParser.  Lines beginning with # are treated as comments
 *
 * File can be specified as a absolute, relative or resource.
 * Two properties can be set:
 * file.query.maker.file=<Full path to file containing queries>
 * <br/>
 * file.query.maker.default.field=<Name of default field - Default value is "body">
 *
 * Example:
 * file.query.maker.file=c:/myqueries.txt
 * file.query.maker.default.field=body
 */
public class FileBasedQueryMaker extends AbstractQueryMaker implements QueryMaker{


  @Override
  protected Query[] prepareQueries() throws Exception {

    Analyzer anlzr = NewAnalyzerTask.createAnalyzer(config.get("analyzer",
            "org.apache.lucene.analysis.standard.StandardAnalyzer"));
    String defaultField = config.get("file.query.maker.default.field", DocMaker.BODY_FIELD);
    QueryParser qp = new QueryParser(Version.LUCENE_CURRENT, defaultField, anlzr);
    qp.setAllowLeadingWildcard(true);

    List<Query> qq = new ArrayList();
    String fileName = config.get("file.query.maker.file", null);
    if (fileName != null)
    {
      File file = new File(fileName);
      Reader reader = null;
      if (file.exists()) {
        reader = new FileReader(file);
      } else {
        //see if we can find it as a resource
        InputStream asStream = FileBasedQueryMaker.class.getClassLoader().getResourceAsStream(fileName);
        if (asStream != null) {
          reader = new InputStreamReader(asStream);
        }
      }
      if (reader != null) {
        try {
          BufferedReader buffered = new BufferedReader(reader);
          String line = null;
          int lineNum = 0;
          while ((line = buffered.readLine()) != null) {
            line = line.trim();
            if (line.length() != 0 && !line.startsWith("#")) {
              try {
                qq.add(qp.parse(line));
              } catch (ParseException e) {
                System.err.println("Exception: " + e.getMessage() + " occurred while parsing line: " + lineNum + " Text: " + line);
              }
            }
            lineNum++;
          }
        } finally {
          reader.close();
        }
      } else {
        System.err.println("No Reader available for: " + fileName);
      }
      
    }
    return qq.toArray(new Query[qq.size()]) ;
  }
}

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