book.Indexer.java Source code

Introduction

Here is the source code for book.Indexer.java

Source

package book;

/**
 * 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 org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.Directory;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.FileReader;

// From chapter 1

/**
 * This code was originally written for Erik's Lucene intro java.net article
 */
public class Indexer {

    public static void main(String[] args) throws Exception {
        if (args.length != 2) {
            throw new IllegalArgumentException(
                    "Usage: java " + Indexer.class.getName() + " <index dir> <data dir>");
        }
        String indexDir = args[0]; // 1
        String dataDir = args[1]; // 2

        long start = System.currentTimeMillis();
        Indexer indexer = new Indexer(indexDir);
        int numIndexed;
        try {
            numIndexed = indexer.index(dataDir, new TextFilesFilter());
        } finally {
            indexer.close();
        }
        long end = System.currentTimeMillis();

        System.out.println("Indexing " + numIndexed + " files took " + (end - start) + " milliseconds");
    }

    private IndexWriter writer;

    public Indexer(String indexDir) throws IOException {
        Directory dir = FSDirectory.open(new File(indexDir).toPath());

        Analyzer analyzer = new StandardAnalyzer();
        IndexWriterConfig iwc = new IndexWriterConfig(analyzer);

        writer = new IndexWriter(dir, iwc); // 3 modified
    }

    public void close() throws IOException {
        writer.close(); // 4
    }

    public int index(String dataDir, FileFilter filter) throws Exception {

        File[] files = new File(dataDir).listFiles();

        for (File f : files) {
            if (!f.isDirectory() && !f.isHidden() && f.exists() && f.canRead()
                    && (filter == null || filter.accept(f))) {
                indexFile(f);
            }
        }

        return writer.numDocs(); // 5
    }

    private static class TextFilesFilter implements FileFilter {
        public boolean accept(File path) {
            return path.getName().toLowerCase() // 6
                    .endsWith(".txt"); // 6
        }
    }

    protected Document getDocument(File f) throws Exception {

        Document doc = new Document();
        doc.add(new TextField("contents", new FileReader(f)));
        // was: doc.add(new Field("contents", new FileReader(f))); //7
        doc.add(new StringField("filename", f.getName(), Field.Store.YES));
        /* was: doc.add(new Field("filename", f.getName(), Field.Store.YES,
           Field.Index.NOT_ANALYZED));//8 */
        doc.add(new StringField("fullpath", f.getCanonicalPath(), Field.Store.YES));
        /* was: doc.add(new Field("fullpath", f.getCanonicalPath(),
           Field.Store.YES, Field.Index.NOT_ANALYZED));// 9 */
        return doc;
    }

    private void indexFile(File f) throws Exception {
        System.out.println("Indexing " + f.getCanonicalPath());
        Document doc = getDocument(f);
        writer.addDocument(doc); // 10
    }
}

/*
 * #1 Create index in this directory 
 * #2 Index *.txt files from this directory 
 * #3 Create Lucene IndexWriter 
 * #4 Close IndexWriter 
 * #5 Return number of documents indexed 
 * #6 Index .txt files only, using FileFilter 
 * #7 Index file content
 * #8 Index file name
 * #9 Index file full path
 * #10 Add document to Lucene index
 */