Lucene example source code file (LineFileDocs.java)

This example Lucene source code file (LineFileDocs.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

atomicinteger, bufferedreader, docstate, docstate, document, field, field, file, io, ioexception, ioexception, linefiledocs, string, string, threadlocal, util, zip

The Lucene LineFileDocs.java source code

package org.apache.lucene.util;

/**
 * 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.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.zip.GZIPInputStream;
import java.util.Random;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;

/** Minimal port of contrib/benchmark's LneDocSource +
 * DocMaker, so tests can enum docs from a line file created
 * by contrib/benchmark's WriteLineDoc task */
public class LineFileDocs implements Closeable {

  private BufferedReader reader;
  private final static int BUFFER_SIZE = 1 << 16;     // 64K
  private final AtomicInteger id = new AtomicInteger();
  private final String path;

  /** If forever is true, we rewind the file at EOF (repeat
   * the docs over and over) */
  public LineFileDocs(Random random, String path) throws IOException {
    this.path = path;
    open(random);
  }

  public LineFileDocs(Random random) throws IOException {
    this(random, LuceneTestCase.TEST_LINE_DOCS_FILE);
  }

  public synchronized void close() throws IOException {
    if (reader != null) {
      reader.close();
      reader = null;
    }
  }

  private synchronized void open(Random random) throws IOException {
    InputStream is = getClass().getResourceAsStream(path);
    if (is == null) {
      // if its not in classpath, we load it as absolute filesystem path (e.g. Hudson's home dir)
      is = new FileInputStream(path);
    }
    File file = new File(path);
    long size;
    if (file.exists()) {
      size = file.length();
    } else {
      size = is.available();
    }
    if (path.endsWith(".gz")) {
      is = new GZIPInputStream(is);
      // guestimate:
      size *= 2.8;
    }

    reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), BUFFER_SIZE);

    // Override sizes for currently "known" line files:
    if (path.equals("europarl.lines.txt.gz")) {
      size = 15129506L;
    } else if (path.equals("/home/hudson/lucene-data/enwiki.random.lines.txt.gz")) {
      size = 3038178822L;
    }

    // Randomly seek to starting point:
    if (random != null && size > 3) {
      final long seekTo = (random.nextLong()&Long.MAX_VALUE) % (size/3);
      if (LuceneTestCase.VERBOSE) {
        System.out.println("TEST: LineFileDocs: seek to fp=" + seekTo + " on open");
      }
      reader.skip(seekTo);
      reader.readLine();
    }
  }

  public synchronized void reset(Random random) throws IOException {
    close();
    open(random);
    id.set(0);
  }

  private final static char SEP = '\t';

  private static final class DocState {
    final Document doc;
    final Field titleTokenized;
    final Field title;
    final Field body;
    final Field id;
    final Field date;

    public DocState() {
      doc = new Document();
      
      title = new Field("title", "", Field.Store.NO, Field.Index.NOT_ANALYZED_NO_NORMS);
      doc.add(title);

      titleTokenized = new Field("titleTokenized", "", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS);
      doc.add(titleTokenized);

      body = new Field("body", "", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS);
      doc.add(body);

      id = new Field("docid", "", Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS);
      doc.add(id);

      date = new Field("date", "", Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS);
      doc.add(date);
    }
  }

  private final ThreadLocal<DocState> threadDocs = new ThreadLocal();

  /** Note: Document instance is re-used per-thread */
  public Document nextDoc() throws IOException {
    String line;
    synchronized(this) {
      line = reader.readLine();
      if (line == null) {
        // Always rewind at end:
        if (LuceneTestCase.VERBOSE) {
          System.out.println("TEST: LineFileDocs: now rewind file...");
        }
        close();
        open(null);
        line = reader.readLine();
      }
    }

    DocState docState = threadDocs.get();
    if (docState == null) {
      docState = new DocState();
      threadDocs.set(docState);
    }

    int spot = line.indexOf(SEP);
    if (spot == -1) {
      throw new RuntimeException("line: [" + line + "] is in an invalid format !");
    }
    int spot2 = line.indexOf(SEP, 1 + spot);
    if (spot2 == -1) {
      throw new RuntimeException("line: [" + line + "] is in an invalid format !");
    }

    docState.body.setValue(line.substring(1+spot2, line.length()));
    final String title = line.substring(0, spot);
    docState.title.setValue(title);
    docState.titleTokenized.setValue(title);
    docState.date.setValue(line.substring(1+spot, spot2));
    docState.id.setValue(Integer.toString(id.getAndIncrement()));
    return docState.doc;
  }
}