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Lucene example source code file (TrecContentSource.java)

This example Lucene source code file (TrecContentSource.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

dateformatinfo, dec, eee, file, io, ioexception, ioexception, mmm, mmm, nomoredataexception, string, string, text, threadlocal, threadlocal, tue, util

The Lucene TrecContentSource.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 java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.text.DateFormat;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Locale;

import org.apache.lucene.benchmark.byTask.feeds.TrecDocParser.ParsePathType;
import org.apache.lucene.benchmark.byTask.utils.Config;
import org.apache.lucene.benchmark.byTask.utils.StreamUtils;
import org.apache.lucene.benchmark.byTask.utils.StringBuilderReader;
import org.apache.lucene.util.ThreadInterruptedException;

/**
 * Implements a {@link ContentSource} over the TREC collection.
 * <p>
 * Supports the following configuration parameters (on top of
 * {@link ContentSource}):
 * <ul>
 * <li>work.dir - specifies the working directory. Required if "docs.dir"
 * denotes a relative path (<b>default=work).
 * <li>docs.dir - specifies the directory where the TREC files reside.
 * Can be set to a relative path if "work.dir" is also specified
 * (<b>default=trec).
 * <li>trec.doc.parser - specifies the {@link TrecDocParser} class to use for
 * parsing the TREC documents content (<b>default=TrecGov2Parser).
 * <li>html.parser - specifies the {@link HTMLParser} class to use for
 * parsing the HTML parts of the TREC documents content (<b>default=DemoHTMLParser).
 * <li>content.source.encoding - if not specified, ISO-8859-1 is used.
 * <li>content.source.excludeIteration - if true, do not append iteration number to docname
 * </ul>
 */
public class TrecContentSource extends ContentSource {

  private static final class DateFormatInfo {
    DateFormat[] dfs;
    ParsePosition pos;
  }

  public static final String DOCNO = "<DOCNO>";
  public static final String TERMINATING_DOCNO = "</DOCNO>";
  public static final String DOC = "<DOC>";
  public static final String TERMINATING_DOC = "</DOC>";

  /** separator between lines in the byffer */ 
  public static final String NEW_LINE = System.getProperty("line.separator");

  private static final String DATE_FORMATS [] = {
       "EEE, dd MMM yyyy kk:mm:ss z",   // Tue, 09 Dec 2003 22:39:08 GMT
       "EEE MMM dd kk:mm:ss yyyy z",    // Tue Dec 09 16:45:08 2003 EST
       "EEE, dd-MMM-':'y kk:mm:ss z",   // Tue, 09 Dec 2003 22:39:08 GMT
       "EEE, dd-MMM-yyy kk:mm:ss z",    // Tue, 09 Dec 2003 22:39:08 GMT
       "EEE MMM dd kk:mm:ss yyyy",      // Tue Dec 09 16:45:08 2003
       "dd MMM yyyy",                   // 1 March 1994
       "MMM dd, yyyy",                  // February 3, 1994
       "yyMMdd",                        // 910513
       "hhmm z.z.z. MMM dd, yyyy",       // 0901 u.t.c. April 28, 1994
  };

  private ThreadLocal<DateFormatInfo> dateFormats = new ThreadLocal();
  private ThreadLocal<StringBuilderReader> trecDocReader = new ThreadLocal();
  private ThreadLocal<StringBuilder> trecDocBuffer = new ThreadLocal();
  private File dataDir = null;
  private ArrayList<File> inputFiles = new ArrayList();
  private int nextFile = 0;
  private int rawDocSize = 0;

  // Use to synchronize threads on reading from the TREC documents.
  private Object lock = new Object();

  // Required for test
  BufferedReader reader;
  int iteration = 0;
  HTMLParser htmlParser;
  
  private boolean excludeDocnameIteration;
  private TrecDocParser trecDocParser = new TrecGov2Parser(); // default
  ParsePathType currPathType; // not private for tests
  
  private DateFormatInfo getDateFormatInfo() {
    DateFormatInfo dfi = dateFormats.get();
    if (dfi == null) {
      dfi = new DateFormatInfo();
      dfi.dfs = new SimpleDateFormat[DATE_FORMATS.length];
      for (int i = 0; i < dfi.dfs.length; i++) {
        dfi.dfs[i] = new SimpleDateFormat(DATE_FORMATS[i], Locale.US);
        dfi.dfs[i].setLenient(true);
      }
      dfi.pos = new ParsePosition(0);
      dateFormats.set(dfi);
    }
    return dfi;
  }

  private StringBuilder getDocBuffer() {
    StringBuilder sb = trecDocBuffer.get();
    if (sb == null) {
      sb = new StringBuilder();
      trecDocBuffer.set(sb);
    }
    return sb;
  }
  
  Reader getTrecDocReader(StringBuilder docBuffer) {
    StringBuilderReader r = trecDocReader.get();
    if (r == null) {
      r = new StringBuilderReader(docBuffer);
      trecDocReader.set(r);
    } else {
      r.set(docBuffer);
    }
    return r;
  }

  HTMLParser getHtmlParser() {
    return htmlParser;
  }
  
  /**
   * Read until a line starting with the specified <code>lineStart.
   * @param buf buffer for collecting the data if so specified/ 
   * @param lineStart line start to look for, must not be null.
   * @param collectMatchLine whether to collect the matching line into <code>buffer.
   * @param collectAll whether to collect all lines into <code>buffer.
   * @throws IOException
   * @throws NoMoreDataException
   */
   private void read(StringBuilder buf, String lineStart, 
       boolean collectMatchLine, boolean collectAll) throws IOException, NoMoreDataException {
    String sep = "";
    while (true) {
      String line = reader.readLine();

      if (line == null) {
        openNextFile();
        continue;
      }

      rawDocSize += line.length();

      if (lineStart!=null && line.startsWith(lineStart)) {
        if (collectMatchLine) {
          buf.append(sep).append(line);
          sep = NEW_LINE;
        }
        return;
      }

      if (collectAll) {
        buf.append(sep).append(line);
        sep = NEW_LINE;
      }
    }
  }
  
  void openNextFile() throws NoMoreDataException, IOException {
    close();
    currPathType = null;
    while (true) {
      if (nextFile >= inputFiles.size()) { 
        // exhausted files, start a new round, unless forever set to false.
        if (!forever) {
          throw new NoMoreDataException();
        }
        nextFile = 0;
        iteration++;
      }
      File f = inputFiles.get(nextFile++);
      if (verbose) {
        System.out.println("opening: " + f + " length: " + f.length());
      }
      try {
        InputStream inputStream = StreamUtils.inputStream(f); // support either gzip, bzip2, or regular text file, by extension  
        reader = new BufferedReader(new InputStreamReader(inputStream, encoding), StreamUtils.BUFFER_SIZE);
        currPathType = TrecDocParser.pathType(f);
        return;
      } catch (Exception e) {
        if (verbose) {
          System.out.println("Skipping 'bad' file " + f.getAbsolutePath()+" due to "+e.getMessage());
          continue;
        }
        throw new NoMoreDataException();
      }
    }
  }

  public Date parseDate(String dateStr) {
    dateStr = dateStr.trim();
    DateFormatInfo dfi = getDateFormatInfo();
    for (int i = 0; i < dfi.dfs.length; i++) {
      DateFormat df = dfi.dfs[i];
      dfi.pos.setIndex(0);
      dfi.pos.setErrorIndex(-1);
      Date d = df.parse(dateStr, dfi.pos);
      if (d != null) {
        // Parse succeeded.
        return d;
      }
    }
    // do not fail test just because a date could not be parsed
    if (verbose) {
      System.out.println("failed to parse date (assigning 'now') for: " + dateStr);
    }
    return null; 
  }
  
  @Override
  public void close() throws IOException {
    if (reader == null) {
      return;
    }

    try {
      reader.close();
    } catch (IOException e) {
      if (verbose) {
        System.out.println("failed to close reader !");
        e.printStackTrace(System.out);
      }
    }
    reader = null;
  }

  @Override
  public DocData getNextDocData(DocData docData) throws NoMoreDataException, IOException {
    String name = null;
    StringBuilder docBuf = getDocBuffer();
    ParsePathType parsedPathType;
    
    // protect reading from the TREC files by multiple threads. The rest of the
    // method, i.e., parsing the content and returning the DocData can run unprotected.
    synchronized (lock) {
      if (reader == null) {
        openNextFile();
      }
      
      // 1. skip until doc start - required for all TREC formats
      docBuf.setLength(0);
      read(docBuf, DOC, false, false);
      
      // save parsedFile for passing trecDataParser after the sync block, in 
      // case another thread will open another file in between.
      parsedPathType = currPathType;
      
      // 2. name - required for all TREC formats
      docBuf.setLength(0);
      read(docBuf, DOCNO, true, false);
      name = docBuf.substring(DOCNO.length(), docBuf.indexOf(TERMINATING_DOCNO,
          DOCNO.length())).trim();
      
      if (!excludeDocnameIteration) {
        name = name + "_" + iteration;
      }

      // 3. read all until end of doc
      docBuf.setLength(0);
      read(docBuf, TERMINATING_DOC, false, true);
    }
      
    // count char length of text to be parsed (may be larger than the resulted plain doc body text).
    addBytes(docBuf.length()); 

    // This code segment relies on HtmlParser being thread safe. When we get 
    // here, everything else is already private to that thread, so we're safe.
    try {
      docData = trecDocParser.parse(docData, name, this, docBuf, parsedPathType);
      addDoc();
    } catch (InterruptedException ie) {
      throw new ThreadInterruptedException(ie);
    }

    return docData;
  }

  @Override
  public void resetInputs() throws IOException {
    synchronized (lock) {
      super.resetInputs();
      close();
      nextFile = 0;
      iteration = 0;
    }
  }

  @Override
  public void setConfig(Config config) {
    super.setConfig(config);
    // dirs
    File workDir = new File(config.get("work.dir", "work"));
    String d = config.get("docs.dir", "trec");
    dataDir = new File(d);
    if (!dataDir.isAbsolute()) {
      dataDir = new File(workDir, d);
    }
    // files
    collectFiles(dataDir, inputFiles);
    if (inputFiles.size() == 0) {
      throw new IllegalArgumentException("No files in dataDir: " + dataDir);
    }
    // trec doc parser
    try {
      String trecDocParserClassName = config.get("trec.doc.parser", "org.apache.lucene.benchmark.byTask.feeds.TrecGov2Parser");
      trecDocParser = Class.forName(trecDocParserClassName).asSubclass(TrecDocParser.class).newInstance();
    } catch (Exception e) {
      // Should not get here. Throw runtime exception.
      throw new RuntimeException(e);
    }
    // html parser
    try {
      String htmlParserClassName = config.get("html.parser",
          "org.apache.lucene.benchmark.byTask.feeds.DemoHTMLParser");
      htmlParser = Class.forName(htmlParserClassName).asSubclass(HTMLParser.class).newInstance();
    } catch (Exception e) {
      // Should not get here. Throw runtime exception.
      throw new RuntimeException(e);
    }
    // encoding
    if (encoding == null) {
      encoding = "ISO-8859-1";
    }
    // iteration exclusion in doc name 
    excludeDocnameIteration = config.get("content.source.excludeIteration", false);
  }

}

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