com.mathworks.xzheng.tools.BerkeleyDbJEIndexer.java Source code

Introduction

Here is the source code for com.mathworks.xzheng.tools.BerkeleyDbJEIndexer.java

Source

package com.mathworks.xzheng.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 java.io.File;
import java.io.IOException;

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

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

// 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_46), 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
*/