BerkeleyDbJEIndexer.java

package lia.tools;

/**
 * Copyright Manning Publications Co.
 *
 * 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
 *
 *     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 lan      
*/

import com.sleepycat.je.Environment;
import com.sleepycat.je.EnvironmentConfig;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseConfig;
import com.sleepycat.je.Transaction;
import com.sleepycat.je.DatabaseException;

import java.io.File;
import java.io.IOException;

import org.apache.lucene.store.je.JEDirectory;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.util.Version;

// From chapter 9

/** Same as BerkeleyDbIndexer, but uses the Java edition of
 *  Berkeley DB */

public class BerkeleyDbJEIndexer {
  public static void main(String[] args)
    throws IOException, DatabaseException {
    if (args.length != 1) {
      System.err.println("Usage: BerkeleyDbIndexer <index dir>");
      System.exit(-1);
    }

    File indexFile = new File(args[0]);

    if (indexFile.exists()) {                      // A
      File[] files = indexFile.listFiles();        // A
      for (int i = 0; i < files.length; i++)        // A
        if (files[i].getName().startsWith("__"))        // A
          files[i].delete();        // A
      indexFile.delete();        // A
    }

    indexFile.mkdir();

    EnvironmentConfig envConfig = new EnvironmentConfig();  // B
    DatabaseConfig dbConfig = new DatabaseConfig();         // B

    envConfig.setTransactional(true);           // B
    envConfig.setAllowCreate(true);            // B
    dbConfig.setTransactional(true);          // B
    dbConfig.setAllowCreate(true);            // B

    Environment env = new Environment(indexFile, envConfig);   // C

    Transaction txn = env.beginTransaction(null, null);          // C
    Database index = env.openDatabase(txn, "__index__", dbConfig);   // C
    Database blocks = env.openDatabase(txn, "__blocks__", dbConfig);   // C
    txn.commit();   // C
    txn = env.beginTransaction(null, null);                          // C

    JEDirectory directory = new JEDirectory(txn, index, blocks);    // D

    IndexWriter writer = new IndexWriter(directory,
                                         new StandardAnalyzer(Version.LUCENE_30),
                                         true,
                                         IndexWriter.MaxFieldLength.UNLIMITED);

    Document doc = new Document();
    doc.add(new Field("contents", "The quick brown fox...",     
                      Field.Store.YES, Field.Index.ANALYZED));
    writer.addDocument(doc);

    writer.optimize();
    writer.close();

    directory.close();
    txn.commit();

    index.close();
    blocks.close();
    env.close();

    System.out.println("Indexing Complete");
  }
}

/*
  #A Remove existing index, if present
  #B Configure BDB's environment and database
  #C Open database and transaction
  #D Create JEDirectory
*/