Example usage for org.apache.lucene.store FSDirectory open

List of usage examples for org.apache.lucene.store FSDirectory open

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Introduction

In this page you can find the example usage for org.apache.lucene.store FSDirectory open.

Prototype

public static FSDirectory open(Path path) throws IOException

Source Link

Document

Creates an FSDirectory instance, trying to pick the best implementation given the current environment.

Usage

From source file:SearchFiles.java

License:Apache License

/** Simple command-line based search demo. */
public static void main(String[] args) throws Exception {
    String usage = "Usage:\tjava org.apache.lucene.demo.SearchFiles [-index dir] [-field f] [-repeat n] [-queries file] [-query string] [-raw] [-paging hitsPerPage]\n\nSee http://lucene.apache.org/core/4_1_0/demo/ for details.";
    if (args.length > 0 && ("-h".equals(args[0]) || "-help".equals(args[0]))) {
        System.out.println(usage);
        System.exit(0);//from   w  ww .j a  v a 2  s . c o  m
    }

    String index = "index";
    String field = "contents";
    String queries = null;
    int repeat = 0;
    boolean raw = false;
    String queryString = null;
    int hitsPerPage = 10;

    for (int i = 0; i < args.length; i++) {
        if ("-index".equals(args[i])) {
            index = args[i + 1];
            i++;
        } else if ("-field".equals(args[i])) {
            field = args[i + 1];
            i++;
        } else if ("-queries".equals(args[i])) {
            queries = args[i + 1];
            i++;
        } else if ("-query".equals(args[i])) {
            queryString = args[i + 1];
            i++;
        } else if ("-repeat".equals(args[i])) {
            repeat = Integer.parseInt(args[i + 1]);
            i++;
        } else if ("-raw".equals(args[i])) {
            raw = true;
        } else if ("-paging".equals(args[i])) {
            hitsPerPage = Integer.parseInt(args[i + 1]);
            if (hitsPerPage <= 0) {
                System.err.println("There must be at least 1 hit per page.");
                System.exit(1);
            }
            i++;
        }
    }

    IndexReader reader = DirectoryReader.open(FSDirectory.open(Paths.get(index)));
    IndexSearcher searcher = new IndexSearcher(reader);
    Analyzer analyzer = new StandardAnalyzer();

    BufferedReader in = null;
    if (queries != null) {
        in = Files.newBufferedReader(Paths.get(queries), StandardCharsets.UTF_8);
    } else {
        in = new BufferedReader(new InputStreamReader(System.in, StandardCharsets.UTF_8));
    }
    QueryParser parser = new QueryParser(field, analyzer);
    while (true) {
        if (queries == null && queryString == null) { // prompt the user
            System.out.println("Enter query: ");
        }

        String line = queryString != null ? queryString : in.readLine();

        if (line == null || line.length() == -1) {
            break;
        }

        line = line.trim();
        if (line.length() == 0) {
            break;
        }

        Query query = parser.parse(line);
        System.out.println("Searching for: " + query.toString(field));

        if (repeat > 0) { // repeat & time as benchmark
            Date start = new Date();
            for (int i = 0; i < repeat; i++) {
                searcher.search(query, 100);
            }
            Date end = new Date();
            System.out.println("Time: " + (end.getTime() - start.getTime()) + "ms");
        }

        doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null);

        if (queryString != null) {
            break;
        }
    }
    reader.close();
}

From source file:VocabDumper.java

void printWords() throws IOException {
    IndexReader indexReader = DirectoryReader.open(FSDirectory.open(indexDir));
    Fields fields = MultiFields.getFields(indexReader);

    String[] fieldNames = { MSIRDoc.FIELD_TITLE_EN, MSIRDoc.FIELD_EN, MSIRDoc.FIELD_TITLE_HN,
            MSIRDoc.FIELD_HN };/*from  w  w  w. ja va2 s . c  o m*/

    for (String fieldName : fieldNames) {
        Terms terms = fields.terms(fieldName);
        TermsEnum iterator = terms.iterator(null);
        BytesRef byteRef = null;
        while ((byteRef = iterator.next()) != null) {
            String term = new String(byteRef.bytes, byteRef.offset, byteRef.length);
            if (term.indexOf('#') == -1)
                System.out.println(term);
        }
    }
}

From source file:WriteIndex.java

License:Apache License

/**
 * @param args//w w  w .  j av  a  2s . c o  m
 */
public static void main(String[] args) throws IOException {

    File docs = new File("documents");
    File indexDir = new File(INDEX_DIRECTORY);

    Directory directory = FSDirectory.open(indexDir);

    Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_35);
    IndexWriterConfig conf = new IndexWriterConfig(Version.LUCENE_35, analyzer);
    IndexWriter writer = new IndexWriter(directory, conf);
    writer.deleteAll();

    for (File file : docs.listFiles()) {
        Metadata metadata = new Metadata();
        ContentHandler handler = new BodyContentHandler();
        ParseContext context = new ParseContext();
        Parser parser = new AutoDetectParser();
        InputStream stream = new FileInputStream(file);
        try {
            parser.parse(stream, handler, metadata, context);
        } catch (TikaException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        } finally {
            stream.close();
        }

        String text = handler.toString();
        String fileName = file.getName();

        Document doc = new Document();
        doc.add(new Field("file", fileName, Store.YES, Index.NO));

        for (String key : metadata.names()) {
            String name = key.toLowerCase();
            String value = metadata.get(key);

            if (StringUtils.isBlank(value)) {
                continue;
            }

            if ("keywords".equalsIgnoreCase(key)) {
                for (String keyword : value.split(",?(\\s+)")) {
                    doc.add(new Field(name, keyword, Store.YES, Index.NOT_ANALYZED));
                }
            } else if ("title".equalsIgnoreCase(key)) {
                doc.add(new Field(name, value, Store.YES, Index.ANALYZED));
            } else {
                doc.add(new Field(name, fileName, Store.YES, Index.NOT_ANALYZED));
            }
        }
        doc.add(new Field("text", text, Store.NO, Index.ANALYZED));
        writer.addDocument(doc);

    }

    writer.commit();
    writer.deleteUnusedFiles();

    System.out.println(writer.maxDoc() + " documents written");
}

From source file:ContentBasedAnalysis.java

License:Apache License

/** Simple command-line based search demo. */
public static void main(String[] args) throws Exception {
    String usage = "Usage:\tjava QueryConvert [-index dir]";
    if (args.length > 0 && ("-h".equals(args[0]) || "-help".equals(args[0]))) {
        System.out.println(usage);
        System.exit(0);//from   w  ww.  ja v a2s  .c  o m
    }

    String index = "index";
    String field = "contents";
    String queries = null;
    String queryString = null;

    for (int i = 0; i < args.length; i++) {
        if ("-index".equals(args[i])) {
            index = args[i + 1];
            i++;
        } else if ("-field".equals(args[i])) {
            field = args[i + 1];
            i++;
        }
    }

    // Creation of reader and a searcher for the index
    IndexReader reader = IndexReader.open(FSDirectory.open(new File(index)));
    IndexSearcher searcher = new IndexSearcher(reader);

    // Reader to read File Names
    BufferedReader in = null;
    if (queries != null) {
        in = new BufferedReader(new InputStreamReader(new FileInputStream(queries), "UTF-8"));
    } else {
        in = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
    }

    while (true) {
        System.out.println("Enter filename 1 (or hit <RETURN>): ");
        String f1 = in.readLine();
        if (f1 == null || f1.length() == -1)
            break;
        f1 = f1.trim();
        if (f1.length() == 0)
            break;
        System.out.println("Enter filename 2: ");
        String f2 = in.readLine();
        int id1 = findDocId(searcher, f1);
        if (id1 < 0) {
            System.out.println("No file " + f1 + " found in index!");
            break;
        }
        int id2 = findDocId(searcher, f2);
        if (id1 < 0) {
            System.out.println("No file " + f1 + " found in index!");
            break;
        }

        // Conversion to TF-IDF format
        TermWeight[] v1 = toTfIdf(reader, id1);
        TermWeight[] v2 = toTfIdf(reader, id2);

        System.out.println("The cosine similarity of the two files is: " + cosineSimilarity(v1, v2));

    }
    searcher.close();
    reader.close();
}

From source file:SearcherTest.java

@Before
public void setUp() throws Exception {
    dir = FSDirectory.open(Paths.get("E:\\lucene\\idx"));
    reader = DirectoryReader.open(dir);/*from  w  w  w.  j av a 2 s .c o  m*/
    is = new IndexSearcher(reader);
}

From source file:MakeLuceneIndex.java

License:Apache License

/** Index all text files under a directory. 
 * @throws UnsupportedEncodingException 
 * @throws FileNotFoundException */
public static void main(String[] args) throws FileNotFoundException, UnsupportedEncodingException {
    String baseDir = "/home/chrisschaefer/";
    //String wikiDumpFile = "Downloads/enwiki-20130604-pages-articles.xml.bz2";
    String wikiDumpFile = "enwiki-20130604-pages-articlese.xml.bz2";
    String luceneIndexName = "enwiki-20130604-lucene2";

    System.currentTimeMillis();/*from  w  w  w . ja v  a 2  s.  co m*/
    boolean bIgnoreStubs = false;

    for (int i = 0; i < args.length; ++i) {
        if (args[i].equals("-luceneindex"))
            luceneIndexName = args[++i];

        if (args[i].equals("-basedir"))
            baseDir = args[++i];

        if (args[i].equals("-dumpfile"))
            wikiDumpFile = args[++i];

        if (args[i].equals("-includestubs"))
            bIgnoreStubs = true;
    }
    String rawTextPath = baseDir + luceneIndexName + "-raw-text.txt";
    String logPath = baseDir + luceneIndexName + ".log";
    PrintWriter artikelTextWriter = new PrintWriter(rawTextPath, "UTF-8");
    PrintWriter logger = new PrintWriter(logPath, "UTF-8");
    logger.println("Indexing to directory '" + baseDir + luceneIndexName + "'");
    System.out.println("Indexing to directory '" + baseDir + luceneIndexName + "'");

    Date start = new Date();

    try {

        Directory dir = FSDirectory.open(new File(baseDir + luceneIndexName));

        Analyzer analyzer = new WikipediaAnalyzer();
        //         Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_43);
        IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_43, analyzer);

        // Create a new index in the directory, removing any
        // previously indexed documents:
        iwc.setOpenMode(OpenMode.CREATE);
        iwc.setSimilarity(new ESASimilarity());

        // Optional: for better indexing performance, if you
        // are indexing many documents, increase the RAM
        // buffer.  But if you do this, increase the max heap
        // size to the JVM (eg add -Xmxm or -Xmx1g):
        //
        iwc.setRAMBufferSizeMB(2000.0);

        IndexWriter writer = new IndexWriter(dir, iwc);

        Extractor wikidumpExtractor = new Extractor(baseDir + File.separator + wikiDumpFile);
        wikidumpExtractor.setLinkSeparator("_");
        wikidumpExtractor.setCategorySeparator("_");
        wikidumpExtractor.setTitleSeparator(" ");

        int iStubs = 0;
        int iArticleCount = 0;
        int iSkippedPageCount = 0;
        long iStartTime = java.lang.System.nanoTime();
        long iTime = iStartTime;

        while (wikidumpExtractor.nextPage()) {
            if (wikidumpExtractor.getPageType() != Extractor.PageType.ARTICLE) {
                ++iSkippedPageCount;
                continue;
            }

            if (bIgnoreStubs && wikidumpExtractor.getStub()) {
                ++iStubs;
                continue;
            }

            // skip pages with less than 5 out links
            if (wikidumpExtractor.getPageLinkList(true).size() < 5) {
                ++iSkippedPageCount;
                continue;
            }
            if (wikidumpExtractor.getPageCategories().equals("")) {
                ++iSkippedPageCount;
                logger.println("skipped because of stop category: " + wikidumpExtractor.getPageTitle(false));
                continue;
            } else {
                for (String link : wikidumpExtractor.getPageLinkList(false)) {
                    //                    artikelTextWriter.println(link);
                    if (_inLinks.containsKey(link)) {
                        int tmp = _inLinks.get(link);
                        tmp++;
                        _inLinks.put(link, tmp);
                    } else {
                        _inLinks.put(link, 1);
                    }
                }
            }
            if (wikidumpExtractor.getPageText().equals("")) {
                ++iSkippedPageCount;
                continue;
            }
            artikelTextWriter.println(
                    wikidumpExtractor.getPageTitle(false) + "\t" + wikidumpExtractor.getPageText(false));

            ++iArticleCount;

            if (iArticleCount % 1000 == 0) {
                logger.println(new Date().toString() + " phase 1 -- iArticleCount: " + iArticleCount
                        + " iSkippedPageCount: " + iSkippedPageCount);
            }
        }
        artikelTextWriter.close();
        iArticleCount = 0;

        PrintWriter artikelInLinkWriter = new PrintWriter(baseDir + luceneIndexName + "-inlinks.txt", "UTF-8");
        BufferedReader br = new BufferedReader(new FileReader(rawTextPath));
        String line = br.readLine();

        while (line != null) {
            int endOfTitle = line.indexOf("\t");
            String title = line.substring(0, endOfTitle);
            if (_inLinks.containsKey(title)) {
                int inlinks = _inLinks.get(title);
                artikelInLinkWriter.println(title + "\t" + inlinks);
                if (inlinks > 4) {
                    //System.out.println("inlinks > 0 ");
                    Document doc = new Document();
                    ++iArticleCount;

                    //                    wikidumpExtractor.setTitleSeparator( "_" );
                    //                    doc.add( new TextField( "url_title", wikidumpExtractor.getPageTitle( false ), Field.Store.YES) );

                    // doc.add( new TextField( "title", wikidumpExtractor.getPageTitle( false ), Field.Store.YES) );
                    //doc.add(new LongField("wiki_id", wikidumpExtractor.getPageId(), Field.Store.YES));
                    doc.add(new TextField("contents", title + " " + title + " " + title + " " + title + " "
                            + line.substring(endOfTitle + 1), Field.Store.NO));
                    //                  System.out.println(title + " " + 
                    //                        title + " " + 
                    //                        title + " " + 
                    //                        title + " " +
                    //                        line.substring(endOfTitle+1));

                    writer.addDocument(doc);

                    if (iArticleCount % 1000 == 0) {
                        writer.commit();
                        logger.println(new Date().toString() + " phase 2 -- iArticleCount: " + iArticleCount
                                + " iSkippedPageCount: " + iSkippedPageCount);
                    }
                }
            } else {
                artikelInLinkWriter.println(title + "\t0");
            }
            line = br.readLine();
        }
        br.close();
        artikelInLinkWriter.close();

        // NOTE: if you want to maximize search performance,
        // you can optionally call forceMerge here.  This can be
        // a terribly costly operation, so generally it's only
        // worth it when your index is relatively static (ie
        // you're done adding documents to it):
        //
        writer.commit();
        writer.forceMerge(1);
        writer.close();

        Date end = new Date();
        String endStatement = end.getTime() - start.getTime() + " total milliseconds ("
                + (end.getTime() - start.getTime()) / 3600000.0 + " hours), " + iArticleCount + " Articles.";
        logger.println(endStatement);
        System.out.println(endStatement);
        logger.close();
    } catch (Exception e) {
        System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage());
    }
}

From source file:MakeLuceneIndexPreprocessed.java

License:Apache License

/** Index all text files under a directory. 
 * @throws UnsupportedEncodingException 
 * @throws FileNotFoundException */
public static void main(String[] args) throws FileNotFoundException, UnsupportedEncodingException {
    String baseDir = "/home/chrisschaefer/";

    String inputLuceneIndexName = "2013-06-18-lucene-gab";
    String luceneIndexName = "2013-06-18-lucene-gab-standard";

    System.currentTimeMillis();// ww  w.j a v  a2 s . co  m

    for (int i = 0; i < args.length; ++i) {
        if (args[i].equals("-inputluceneindex"))
            inputLuceneIndexName = args[++i];

        if (args[i].equals("-outputluceneindex"))
            luceneIndexName = args[++i];

        if (args[i].equals("-basedir"))
            baseDir = args[++i];

    }
    String rawTextPath = baseDir + inputLuceneIndexName + "-raw-text.txt";
    String artikelInLinksPath = baseDir + inputLuceneIndexName + "-inlinks.txt";
    String logPath = baseDir + inputLuceneIndexName + ".log";

    PrintWriter logger = new PrintWriter(logPath, "UTF-8");
    logger.println("Indexing to directory '" + baseDir + luceneIndexName + "'");
    System.out.println("Indexing to directory '" + baseDir + luceneIndexName + "'");

    Date start = new Date();
    logger.println(start.toString() + " iArticleCount: 0 iSkippedPageCount: 0");

    try {

        Directory dir = FSDirectory.open(new File(baseDir + luceneIndexName));

        //         Analyzer analyzer = new WikipediaAnalyzer();
        Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_43);
        IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_43, analyzer);

        // Create a new index in the directory, removing any
        // previously indexed documents:
        iwc.setOpenMode(OpenMode.CREATE);

        // Optional: for better indexing performance, if you
        // are indexing many documents, increase the RAM
        // buffer.  But if you do this, increase the max heap
        // size to the JVM (eg add -Xmxm or -Xmx1g):
        //
        iwc.setRAMBufferSizeMB(2000.0);
        //         iwc.setSimilarity(new ESASimilarity());

        IndexWriter writer = new IndexWriter(dir, iwc);

        int iArticleCount = 0;
        int iSkippedPageCount = 0;

        BufferedReader rawTextReader = new BufferedReader(new FileReader(rawTextPath));
        BufferedReader artikelInLinksReader = new BufferedReader(new FileReader(artikelInLinksPath));
        String lineText = rawTextReader.readLine();
        String lineLinks = artikelInLinksReader.readLine();

        while (lineText != null) {
            //            String title = lineText.substring(0, lineText.indexOf("\t")); 
            //            while(!title.equals(lineLinks.substring(0, lineLinks.indexOf("\t")))){
            //               lineLinks = artikelInLinksReader.readLine();
            //            }
            int endOfTitle = lineText.indexOf("\t");
            String title = lineText.substring(0, endOfTitle);

            if (Integer.valueOf(lineLinks.substring(lineLinks.indexOf("\t") + 1)) > 0) {
                ++iArticleCount;
                Document doc = new Document();
                doc.add(new TextField("contents", title + " " + title + " " + title + " " + title + " "
                        + lineText.substring(endOfTitle + 1), Field.Store.NO));
                //               System.out.println(title + " " + 
                //               title + " " + 
                //               title + " " + 
                //               title + " " +
                //               lineText.substring(endOfTitle+1));
                writer.addDocument(doc);

                if (iArticleCount % 1000 == 0) {
                    writer.commit();
                    logger.println(new Date().toString() + "phase 2 -- iArticleCount: " + iArticleCount
                            + " iSkippedPageCount: " + iSkippedPageCount);
                    logger.flush();
                }
            }
            lineText = rawTextReader.readLine();
            lineLinks = artikelInLinksReader.readLine();
        }
        rawTextReader.close();
        artikelInLinksReader.close();

        // NOTE: if you want to maximize search performance,
        // you can optionally call forceMerge here.  This can be
        // a terribly costly operation, so generally it's only
        // worth it when your index is relatively static (ie
        // you're done adding documents to it):
        //
        writer.commit();
        writer.forceMerge(1);
        writer.close();

        Date end = new Date();
        String endStatement = end.getTime() - start.getTime() + " total milliseconds ("
                + (end.getTime() - start.getTime()) / 3600000.0 + " hours), " + iArticleCount + " Articles.";
        logger.println(endStatement);
        System.out.println(endStatement);
        logger.close();
    } catch (Exception e) {
        System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage());
    }
}

From source file:FileIndexer.java

License:Apache License

public static void main(String[] args) {
    String usage = "java FileIndexer" + " [-index INDEX_PATH] [-docs DOCS_PATH] [-excludes FILE] [-update]\n\n"
            + "This indexes the documents in DOCS_PATH, creating a Lucene index"
            + "in INDEX_PATH that can be searched with SearchFiles\n"
            + "excludes is an optional list of files to be excluded, one per line.";
    String indexPath = "index";
    String docsPath = null;/*from  w w w .  j a v a  2  s .c  o m*/
    boolean create = true;
    List<String> excludes = new ArrayList<String>();
    for (int i = 0; i < args.length; i++) {
        if ("-index".equals(args[i])) {
            indexPath = args[i + 1];
            i++;
        } else if ("-docs".equals(args[i])) {
            docsPath = args[i + 1];
            i++;
        } else if ("-excludes".equals(args[i])) {
            Scanner sc = null;
            try {
                sc = new Scanner(new File(args[i + 1]));
                i++;
            } catch (FileNotFoundException fnfe) {
                System.err.println(fnfe.getMessage());
                System.exit(1);
            }
            while (sc.hasNext()) {
                excludes.add(sc.next());
            }
            sc.close();
        } else if ("-update".equals(args[i])) {
            create = false;
        }
    }

    if (docsPath == null) {
        System.err.println("Usage: " + usage);
        System.exit(1);
    }

    final Path docDir = Paths.get(docsPath);
    if (!Files.isReadable(docDir)) {
        System.out.println("Document directory '" + docDir.toAbsolutePath()
                + "' does not exist or is not readable, please check the path");
        System.exit(1);
    }

    Date start = new Date();
    try {
        System.out.println("Indexing to directory '" + indexPath + "'...");

        Directory dir = FSDirectory.open(Paths.get(indexPath));
        Analyzer analyzer = new LimitTokenCountAnalyzer(new StandardAnalyzer(), 1000000);
        IndexWriterConfig iwc = new IndexWriterConfig(analyzer);

        if (create) {
            // Create a new index in the directory, removing any
            // previously indexed documents:
            iwc.setOpenMode(OpenMode.CREATE);
        } else {
            // Add new documents to an existing index:
            iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
        }

        // Optional: for better indexing performance, if you
        // are indexing many documents, increase the RAM
        // buffer.  But if you do this, increase the max heap
        // size to the JVM (eg add -Xmx512m or -Xmx1g):
        //
        // iwc.setRAMBufferSizeMB(256.0);

        IndexWriter writer = new IndexWriter(dir, iwc);
        indexDocs(writer, docDir, excludes);

        // NOTE: if you want to maximize search performance,
        // you can optionally call forceMerge here.  This can be
        // a terribly costly operation, so generally it's only
        // worth it when your index is relatively static (ie
        // you're done adding documents to it):
        //
        // writer.forceMerge(1);

        writer.close();

        Date end = new Date();
        System.out.println(end.getTime() - start.getTime() + " total milliseconds");

    } catch (IOException e) {
        System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage());
    }

}

From source file:IrqaQuery.java

License:Apache License

public static void makeIndexWriter(String indexPath, String stopPath, String sim) throws IOException {
    System.out.println("[makeIndexWriter] started");
    System.out.println("[makeIndexWriter]" + stopPath);
    Directory dir = FSDirectory.open(Paths.get(indexPath));
    Analyzer analyzer = new EnglishAnalyzer(StopFilter.makeStopSet(mygetStopwords(stopPath)));
    IndexWriterConfig iwc = new IndexWriterConfig(analyzer);

    if (sim.equals("TFIDF"))
        iwc.setSimilarity(new ClassicSimilarity());
    else if (sim.equals("BM25"))
        iwc.setSimilarity(new BM25Similarity());
    else//www. j  a v  a 2 s. c o  m
        iwc.setSimilarity(new BM25Similarity());

    writer = new IndexWriter(dir, iwc);
}

From source file:IrqaQuery.java

License:Apache License

public static List<Document> query(String index, String stoppath, String question, int numResult, String sim)
        throws Exception {
    IndexReader reader = DirectoryReader.open(FSDirectory.open(Paths.get(index)));
    IndexSearcher searcher = new IndexSearcher(reader);

    Analyzer analyzer = new EnglishAnalyzer(StopFilter.makeStopSet(mygetStopwords(stoppath)));

    if (sim.equals("TFIDF"))
        searcher.setSimilarity(new ClassicSimilarity());
    else if (sim.equals("BM25"))
        searcher.setSimilarity(new BM25Similarity());
    else//from  w w  w . j  a v a 2  s .c om
        searcher.setSimilarity(new BM25Similarity());

    String field = "contents";
    QueryParser parser = new QueryParser(field, analyzer);
    Query query = parser.parse(parser.escape(question));

    TopDocs results = searcher.search(query, numResult);
    ScoreDoc[] hits = results.scoreDocs;
    List<Document> docs = new ArrayList<Document>();

    int numTotalHits = results.totalHits;
    //        System.out.println(numTotalHits + " total matching documents");

    int end = Math.min(numTotalHits, numResult);

    String searchResult = "";
    //        System.out.println("Only results 1 - " + hits.length);

    for (int i = 0; i < end; i++) {
        Document doc = searcher.doc(hits[i].doc);
        docs.add(doc);
    }

    return docs;
}