Example usage for org.apache.lucene.index IndexWriter getConfig

List of usage examples for org.apache.lucene.index IndexWriter getConfig

Introduction

In this page you can find the example usage for org.apache.lucene.index IndexWriter getConfig.

Prototype

public LiveIndexWriterConfig getConfig() 

Source Link

Document

Returns a LiveIndexWriterConfig , which can be used to query the IndexWriter current settings, as well as modify "live" ones.

Usage

From source file:com.paladin.sys.lucene.IndexFiles.java

License:Apache License

/**
 * Indexes the given file using the given writer, or if a directory is given,
 * recurses over files and directories found under the given directory.
 * <p/>/*from  w  w  w  . j a  v a2  s . c o  m*/
 * NOTE: This method indexes one document per input file.  This is slow.  For good
 * throughput, put multiple documents into your input file(s).  An example of this is
 * in the benchmark module, which can create "line doc" files, one document per line,
 * using the
 * <a href="../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html"
 * >WriteLineDocTask</a>.
 *
 * @param writer Writer to the index where the given file/dir info will be stored
 * @param file   The file to index, or the directory to recurse into to find files to index
 * @throws IOException
 */

static void indexDocs(IndexWriter writer, File file) throws IOException {
    // do not try to index files that cannot be read
    if (!file.canRead())
        return;

    if (file.isDirectory() && file.list() != null) {
        String[] files = file.list();
        for (int i = 0; i < files.length; i++)
            indexDocs(writer, new File(file, files[i]));
    } else {
        FileInputStream fis;
        try {
            fis = new FileInputStream(file);
        } catch (FileNotFoundException e) {
            // at least on windows, some temporary files raise this exception with an "access denied" message
            // checking if the file can be read doesn't help
            return;
        }

        try {
            Document doc = new Document();
            // Add the path of the file as a field named "path".  Use a field that is indexed (i.e. searchable), but don't tokenize
            // the field into separate words and don't index term frequency or positional information:
            Field pathField = new Field("path", file.getPath(), Field.Store.YES,
                    Field.Index.NOT_ANALYZED_NO_NORMS);
            pathField.setOmitTermFreqAndPositions(true);
            doc.add(pathField);

            // Add the last modified date of the file a field named "modified". Use a NumericField that is indexed (i.e. efficiently filterable with
            // NumericRangeFilter).  This indexes to milli-second resolution, which is often too fine.  You could instead create a number based on
            // year/month/day/hour/minutes/seconds, down the resolution you require. For example the long value 2011021714 would mean
            // February 17, 2011, 2-3 PM.
            NumericField modifiedField = new NumericField("modified");
            modifiedField.setLongValue(file.lastModified());
            doc.add(modifiedField);

            // Add the contents of the file to a field named "contents".  Specify a Reader, so that the text of the file is tokenized and indexed, but not stored.
            // Note that FileReader expects the file to be in UTF-8 encoding. If that's not the case searching for special characters will fail.
            doc.add(new Field("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));

            if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
                out.println("adding " + file);
                writer.addDocument(doc);
            } else {
                out.println("updating " + file);
                writer.updateDocument(new Term("path", file.getPath()), doc);
            }
        } finally {
            fis.close();
        }
    }
}

From source file:com.qwazr.search.index.IndexInstance.java

License:Apache License

private IndexInstance(SchemaInstance schema, Directory dataDirectory, IndexSettingsDefinition settings,
        LinkedHashMap<String, AnalyzerDefinition> analyzerMap, LinkedHashMap<String, FieldDefinition> fieldMap,
        FileSet fileSet, IndexWriter indexWriter, SearcherManager searcherManager,
        UpdatableAnalyzer queryAnalyzer) {
    this.schema = schema;
    this.fileSet = fileSet;
    this.dataDirectory = dataDirectory;
    this.analyzerMap = analyzerMap;
    this.fieldMap = fieldMap;
    this.indexWriter = indexWriter;
    this.indexWriterConfig = indexWriter.getConfig();
    this.indexAnalyzer = (UpdatableAnalyzer) indexWriterConfig.getAnalyzer();
    this.queryAnalyzer = queryAnalyzer;
    this.snapshotDeletionPolicy = (SnapshotDeletionPolicy) indexWriterConfig.getIndexDeletionPolicy();
    this.settings = settings;
    this.searcherManager = searcherManager;
    this.facetsReaderStateCache = null;
}

From source file:com.sg.business.vault.index.demo.IndexFiles.java

License:Apache License

/**
 * Indexes the given file using the given writer, or if a directory is given,
 * recurses over files and directories found under the given directory.
 * /*from w w  w .  j a  va  2 s  .co m*/
 * NOTE: This method indexes one document per input file.  This is slow.  For good
 * throughput, put multiple documents into your input file(s).  An example of this is
 * in the benchmark module, which can create "line doc" files, one document per line,
 * using the
 * <a href="../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html"
 * >WriteLineDocTask</a>.
 *  
 * @param writer Writer to the index where the given file/dir info will be stored
 * @param file The file to index, or the directory to recurse into to find files to index
 * @throws IOException If there is a low-level I/O error
 */
static void indexDocs(IndexWriter writer, File file) throws IOException {
    // do not try to index files that cannot be read
    if (file.canRead()) {
        if (file.isDirectory()) {
            String[] files = file.list();
            // an IO error could occur
            if (files != null) {
                for (int i = 0; i < files.length; i++) {
                    indexDocs(writer, new File(file, files[i]));
                }
            }
        } else {

            FileInputStream fis;
            try {
                fis = new FileInputStream(file);
            } catch (FileNotFoundException fnfe) {
                // at least on windows, some temporary files raise this exception with an "access denied" message
                // checking if the file can be read doesn't help
                return;
            }

            try {

                // make a new, empty document
                Document doc = new Document();

                // Add the path of the file as a field named "path".  Use a
                // field that is indexed (i.e. searchable), but don't tokenize 
                // the field into separate words and don't index term frequency
                // or positional information:
                Field pathField = new StringField("path", file.getPath(), Field.Store.YES); //$NON-NLS-1$
                doc.add(pathField);

                // Add the last modified date of the file a field named "modified".
                // Use a LongField that is indexed (i.e. efficiently filterable with
                // NumericRangeFilter).  This indexes to milli-second resolution, which
                // is often too fine.  You could instead create a number based on
                // year/month/day/hour/minutes/seconds, down the resolution you require.
                // For example the long value 2011021714 would mean
                // February 17, 2011, 2-3 PM.
                //          doc.add(new LongField("modified", file.lastModified(), Field.Store.NO));

                // Add the contents of the file to a field named "contents".  Specify a Reader,
                // so that the text of the file is tokenized and indexed, but not stored.
                // Note that FileReader expects the file to be in UTF-8 encoding.
                // If that's not the case searching for special characters will fail.
                //          doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));

                try {
                    doc.add(new TextField("contents", FileUtil.getContent(file.getName(), fis), //$NON-NLS-1$
                            Field.Store.NO));
                } catch (Exception e) {
                    e.printStackTrace();
                }

                if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
                    // New index, so we just add the document (no old document can be there):
                    System.out.println("adding " + file); //$NON-NLS-1$
                    writer.addDocument(doc);
                } else {
                    // Existing index (an old copy of this document may have been indexed) so 
                    // we use updateDocument instead to replace the old one matching the exact 
                    // path, if present:
                    System.out.println("updating " + file); //$NON-NLS-1$
                    writer.updateDocument(new Term("path", file.getPath()), doc); //$NON-NLS-1$
                }

            } finally {
                fis.close();
            }
        }
    }
}

From source file:com.slieer.app.lecene3x.IndexFiles.java

License:Apache License

/**
 * Indexes the given file using the given writer, or if a directory is
 * given, recurses over files and directories found under the given
 * directory./*  w w w. j a v  a  2 s .  com*/
 * 
 * NOTE: This method indexes one document per input file. This is slow. For
 * good throughput, put multiple documents into your input file(s). An
 * example of this is in the benchmark module, which can create "line doc"
 * files, one document per line, using the <a href=
 * "../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html"
 * >WriteLineDocTask</a>.
 * 
 * @param writer
 *            Writer to the index where the given file/dir info will be
 *            stored
 * @param file
 *            The file to index, or the directory to recurse into to find
 *            files to index
 * @throws IOException
 *             If there is a low-level I/O error
 */
static void indexDocs(IndexWriter writer, File file) throws IOException {
    // do not try to index files that cannot be read
    if (file.canRead()) {
        if (file.isDirectory()) {
            String[] files = file.list();
            // an IO error could occur
            if (files != null) {
                for (int i = 0; i < files.length; i++) {
                    indexDocs(writer, new File(file, files[i]));
                }
            }
        } else {

            FileInputStream fis;
            try {
                fis = new FileInputStream(file);
            } catch (FileNotFoundException fnfe) {
                // at least on windows, some temporary files raise this
                // exception with an "access denied" message
                // checking if the file can be read doesn't help
                return;
            }

            try {

                // make a new, empty document
                Document doc = new Document();

                // Add the path of the file as a field named "path". Use a
                // field that is indexed (i.e. searchable), but don't
                // tokenize
                // the field into separate words and don't index term
                // frequency
                // or positional information:
                Field pathField = new StringField("path", file.getPath(), Field.Store.YES);
                doc.add(pathField);

                // Add the last modified date of the file a field named
                // "modified".
                // Use a LongField that is indexed (i.e. efficiently
                // filterable with
                // NumericRangeFilter). This indexes to milli-second
                // resolution, which
                // is often too fine. You could instead create a number
                // based on
                // year/month/day/hour/minutes/seconds, down the resolution
                // you require.
                // For example the long value 2011021714 would mean
                // February 17, 2011, 2-3 PM.
                doc.add(new LongField("modified", file.lastModified(), Field.Store.NO));

                // Add the contents of the file to a field named "contents".
                // Specify a Reader,
                // so that the text of the file is tokenized and indexed,
                // but not stored.
                // Note that FileReader expects the file to be in UTF-8
                // encoding.
                // If that's not the case searching for special characters
                // will fail.
                doc.add(new TextField("contents",
                        new BufferedReader(new InputStreamReader(fis, StandardCharsets.UTF_8))));

                if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
                    // New index, so we just add the document (no old
                    // document can be there):
                    System.out.println("adding " + file);
                    writer.addDocument(doc);
                } else {
                    // Existing index (an old copy of this document may have
                    // been indexed) so
                    // we use updateDocument instead to replace the old one
                    // matching the exact
                    // path, if present:
                    System.out.println("updating " + file);
                    writer.updateDocument(new Term("path", file.getPath()), doc);
                }

            } finally {
                fis.close();
            }
        }
    }
}

From source file:com.slieer.lucene.apachedemo.IndexFiles.java

License:Apache License

static void indexDocs(IndexWriter writer, File file) throws IOException {
    // do not try to index files that cannot be read
    if (file.canRead()) {
        if (file.isDirectory()) {
            String[] files = file.list();
            // an IO error could occur
            if (files != null) {
                for (int i = 0; i < files.length; i++) {
                    indexDocs(writer, new File(file, files[i]));
                }//from w  w w.j  a  v a 2  s  .  c  om
            }
        } else {

            FileInputStream fis;
            try {
                fis = new FileInputStream(file);
            } catch (FileNotFoundException fnfe) {
                // at least on windows, some temporary files raise this
                // exception with an "access denied" message
                // checking if the file can be read doesn't help
                return;
            }

            try {

                // make a new, empty document
                Document doc = new Document();

                // Add the path of the file as a field named "path". Use a
                // field that is indexed (i.e. searchable), but don't
                // tokenize
                // the field into separate words and don't index term
                // frequency
                // or positional information:
                Field pathField = new StringField("path", file.getPath(), Field.Store.YES);
                doc.add(pathField);

                // Add the last modified date of the file a field named
                // "modified".
                // Use a LongField that is indexed (i.e. efficiently
                // filterable with
                // NumericRangeFilter). This indexes to milli-second
                // resolution, which
                // is often too fine. You could instead create a number
                // based on
                // year/month/day/hour/minutes/seconds, down the resolution
                // you require.
                // For example the long value 2011021714 would mean
                // February 17, 2011, 2-3 PM.
                doc.add(new LongField("modified", file.lastModified(), Field.Store.NO));

                // Add the contents of the file to a field named "contents".
                // Specify a Reader,
                // so that the text of the file is tokenized and indexed,
                // but not stored.
                // Note that FileReader expects the file to be in UTF-8
                // encoding.
                // If that's not the case searching for special characters
                // will fail.
                doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));

                if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
                    // New index, so we just add the document (no old
                    // document can be there):
                    System.out.println("adding " + file);
                    writer.addDocument(doc);
                } else {
                    // Existing index (an old copy of this document may have
                    // been indexed) so
                    // we use updateDocument instead to replace the old one
                    // matching the exact
                    // path, if present:
                    System.out.println("updating " + file);
                    writer.updateDocument(new Term("path", file.getPath()), doc);
                }

            } finally {
                fis.close();
            }
        }
    }
}

From source file:com.tistory.devyongsik.demo.IndexFiles.java

License:Apache License

/**
 * Indexes the given file using the given writer, or if a directory is given,
 * recurses over files and directories found under the given directory.
 * /* w  ww  . jav a  2s.c o m*/
 * NOTE: This method indexes one document per input file.  This is slow.  For good
 * throughput, put multiple documents into your input file(s).  An example of this is
 * in the benchmark module, which can create "line doc" files, one document per line,
 * using the
 * <a href="../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html"
 * >WriteLineDocTask</a>.
 *  
 * @param writer Writer to the index where the given file/dir info will be stored
 * @param file The file to index, or the directory to recurse into to find files to index
 * @throws IOException
 */
static void indexDocs(IndexWriter writer, File file) throws IOException {
    // do not try to index files that cannot be read
    if (file.canRead()) {
        if (file.isDirectory()) {
            String[] files = file.list();
            // an IO error could occur
            if (files != null) {
                for (int i = 0; i < files.length; i++) {
                    indexDocs(writer, new File(file, files[i])); //10.         .
                }
            }
        } else {

            FileInputStream fis;
            try {
                fis = new FileInputStream(file); //11.    Stream .
            } catch (FileNotFoundException fnfe) {
                // at least on windows, some temporary files raise this exception with an "access denied" message
                // checking if the file can be read doesn't help
                return;
            }

            try {

                // make a new, empty document
                //12.   .  Document  Row.
                Document doc = new Document();

                // Add the path of the file as a field named "path".  Use a
                // field that is indexed (i.e. searchable), but don't tokenize 
                // the field into separate words and don't index term frequency
                // or positional information:

                //13.   Document,  Document     .
                //      .   path   path .
                //          .
                Field pathField = new Field("path", file.getPath(), Field.Store.YES,
                        Field.Index.NOT_ANALYZED_NO_NORMS);
                pathField.setOmitTermFreqAndPositions(true);
                doc.add(pathField);

                // Add the last modified date of the file a field named "modified".
                // Use a NumericField that is indexed (i.e. efficiently filterable with
                // NumericRangeFilter).  This indexes to milli-second resolution, which
                // is often too fine.  You could instead create a number based on
                // year/month/day/hour/minutes/seconds, down the resolution you require.
                // For example the long value 2011021714 would mean
                // February 17, 2011, 2-3 PM.

                //14. Field        .
                //      ,    .
                NumericField modifiedField = new NumericField("modified");
                modifiedField.setLongValue(file.lastModified());
                doc.add(modifiedField);

                // Add the contents of the file to a field named "contents".  Specify a Reader,
                // so that the text of the file is tokenized and indexed, but not stored.
                // Note that FileReader expects the file to be in UTF-8 encoding.
                // If that's not the case searching for special characters will fail.

                //15. path, modified,   contents   Document .
                //       ,    String, Numeric, Reader  
                //         .
                doc.add(new Field("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));

                if (writer.getConfig().getOpenMode() == OpenMode.CREATE) { //16.        add...
                    // New index, so we just add the document (no old document can be there):
                    System.out.println("adding " + file);
                    writer.addDocument(doc);
                } else {
                    // Existing index (an old copy of this document may have been indexed) so 
                    // we use updateDocument instead to replace the old one matching the exact 
                    // path, if present:
                    System.out.println("updating " + file); //17. Create or Update update .
                    //   3.X   API .
                    writer.updateDocument(new Term("path", file.getPath()), doc);
                }

            } finally {
                fis.close();
            }
        }
    }
}

From source file:com.vmware.dcp.services.common.LuceneDocumentIndexService.java

License:Open Source License

private void handleBackup(Operation op, BackupRequest req) throws Throwable {
    SnapshotDeletionPolicy snapshotter = null;
    IndexCommit commit = null;/*  w w w. ja v a  2 s  . c o m*/
    handleMaintenanceImpl(true);
    IndexWriter w = this.writer;
    if (w == null) {
        op.fail(new CancellationException());
        return;
    }
    try {
        // Create a snapshot so the index files won't be deleted.
        snapshotter = (SnapshotDeletionPolicy) w.getConfig().getIndexDeletionPolicy();
        commit = snapshotter.snapshot();

        String indexDirectory = UriUtils.buildUriPath(getHost().getStorageSandbox().getPath(),
                FILE_PATH_LUCENE);

        // Add the files in the commit to a zip file.
        List<URI> fileList = FileUtils.filesToUris(indexDirectory, commit.getFileNames());
        req.backupFile = FileUtils.zipFiles(fileList, this.indexDirectory + "-" + Utils.getNowMicrosUtc());

        op.setBody(req).complete();
    } catch (Exception e) {
        this.logSevere(e);
        throw e;
    } finally {
        if (snapshotter != null) {
            snapshotter.release(commit);
        }
        w.deleteUnusedFiles();
    }
}

From source file:com.vmware.xenon.services.common.LuceneDocumentIndexBackupService.java

License:Open Source License

private void takeSnapshot(Path destinationPath, boolean isZipBackup, InternalDocumentIndexInfo indexInfo)
        throws IOException {

    IndexWriter writer = indexInfo.indexWriter;
    boolean isInMemoryIndex = indexInfo.indexDirectory == null;

    URI storageSandbox = getHost().getStorageSandbox();

    SnapshotDeletionPolicy snapshotter = null;
    IndexCommit commit = null;/*from  w w  w. ja  v a  2 s  .  c  o m*/
    long backupStartTime = System.currentTimeMillis();
    try {
        // Create a snapshot so the index files won't be deleted.
        writer.commit();
        snapshotter = (SnapshotDeletionPolicy) writer.getConfig().getIndexDeletionPolicy();
        commit = snapshotter.snapshot();

        if (isZipBackup) {
            Path tempDir = null;
            try {
                List<URI> fileList = new ArrayList<>();
                if (isInMemoryIndex) {
                    tempDir = Files.createTempDirectory("lucene-in-memory-backup");
                    copyInMemoryLuceneIndexToDirectory(commit, tempDir);
                    List<URI> files = Files.list(tempDir).map(Path::toUri).collect(toList());
                    fileList.addAll(files);
                } else {

                    Path indexDirectoryPath = Paths.get(storageSandbox).resolve(indexInfo.indexDirectory);
                    List<URI> files = commit.getFileNames().stream().map(indexDirectoryPath::resolve)
                            .map(Path::toUri).collect(toList());
                    fileList.addAll(files);
                }

                // Add files in the commit to a zip file.
                FileUtils.zipFiles(fileList, destinationPath.toFile());
            } finally {
                if (tempDir != null) {
                    FileUtils.deleteFiles(tempDir.toFile());
                }
            }
        } else {
            // incremental backup

            // create destination dir if not exist
            if (!Files.exists(destinationPath)) {
                Files.createDirectory(destinationPath);
            }

            Set<String> sourceFileNames = new HashSet<>(commit.getFileNames());

            Set<String> destFileNames = Files.list(destinationPath).filter(Files::isRegularFile)
                    .map(path -> path.getFileName().toString()).collect(toSet());

            Path tempDir = null;
            try {
                Path indexDirectoryPath;
                if (isInMemoryIndex) {
                    // copy files into temp directory and point index directory path to temp dir
                    tempDir = Files.createTempDirectory("lucene-in-memory-backup");
                    copyInMemoryLuceneIndexToDirectory(commit, tempDir);
                    indexDirectoryPath = tempDir;
                } else {
                    indexDirectoryPath = Paths.get(storageSandbox).resolve(indexInfo.indexDirectory);
                }

                // add files exist in source but not in dest
                Set<String> toAdd = new HashSet<>(sourceFileNames);
                toAdd.removeAll(destFileNames);
                for (String filename : toAdd) {
                    Path source = indexDirectoryPath.resolve(filename);
                    Path target = destinationPath.resolve(filename);
                    Files.copy(source, target);
                }

                // delete files exist in dest but not in source
                Set<String> toDelete = new HashSet<>(destFileNames);
                toDelete.removeAll(sourceFileNames);
                for (String filename : toDelete) {
                    Path path = destinationPath.resolve(filename);
                    Files.delete(path);
                }

                long backupEndTime = System.currentTimeMillis();
                logInfo("Incremental backup performed. dir=%s, added=%d, deleted=%d, took=%dms",
                        destinationPath, toAdd.size(), toDelete.size(), backupEndTime - backupStartTime);
            } finally {
                if (tempDir != null) {
                    FileUtils.deleteFiles(tempDir.toFile());
                }
            }
        }
    } finally {
        if (snapshotter != null && commit != null) {
            snapshotter.release(commit);
        }
        writer.deleteUnusedFiles();
    }
}

From source file:com.vmware.xenon.services.common.LuceneDocumentIndexService.java

License:Open Source License

private void handleBackup(Operation op, BackupRequest req) throws Throwable {
    SnapshotDeletionPolicy snapshotter = null;
    IndexCommit commit = null;/*from  w w w  . j a  v  a 2s  .c  om*/
    handleMaintenanceImpl(true);
    IndexWriter w = this.writer;
    if (w == null) {
        op.fail(new CancellationException());
        return;
    }
    try {
        // Create a snapshot so the index files won't be deleted.
        snapshotter = (SnapshotDeletionPolicy) w.getConfig().getIndexDeletionPolicy();
        commit = snapshotter.snapshot();

        String indexDirectory = UriUtils.buildUriPath(getHost().getStorageSandbox().getPath(),
                this.indexDirectory);

        // Add the files in the commit to a zip file.
        List<URI> fileList = FileUtils.filesToUris(indexDirectory, commit.getFileNames());
        req.backupFile = FileUtils.zipFiles(fileList, this.indexDirectory + "-" + Utils.getNowMicrosUtc());

        op.setBody(req).complete();
    } catch (Exception e) {
        this.logSevere(e);
        throw e;
    } finally {
        if (snapshotter != null) {
            snapshotter.release(commit);
        }
        w.deleteUnusedFiles();
    }
}

From source file:com.work.IndexFiles.java

License:Apache License

/** Indexes a single document */
static void indexDoc(IndexWriter writer, Path file, long lastModified) throws IOException {
    try (InputStream stream = Files.newInputStream(file)) {
        // make a new, empty document
        Document doc = new Document();

        // Add the path of the file as a field named "path".  Use a
        // field that is indexed (i.e. searchable), but don't tokenize 
        // the field into separate words and don't index term frequency
        // or positional information:
        Field pathField = new StringField("path", file.toString(), Field.Store.YES);
        doc.add(pathField);//from  w  ww. j  a  v  a2 s .co  m

        // Add the last modified date of the file a field named "modified".
        // Use a LongPoint that is indexed (i.e. efficiently filterable with
        // PointRangeQuery).  This indexes to milli-second resolution, which
        // is often too fine.  You could instead create a number based on
        // year/month/day/hour/minutes/seconds, down the resolution you require.
        // For example the long value 2011021714 would mean
        // February 17, 2011, 2-3 PM.

        // doc.add(new LongPoint("modified", lastModified));
        doc.add(new StringField("modified", lastModified + "", Field.Store.YES));

        // Add the contents of the file to a field named "contents".  Specify a Reader,
        // so that the text of the file is tokenized and indexed, but not stored.
        // Note that FileReader expects the file to be in UTF-8 encoding.
        // If that's not the case searching for special characters will fail.
        doc.add(new TextField("contents",
                new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))));

        if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
            // New index, so we just add the document (no old document can be there):
            System.out.println("adding " + file);
            writer.addDocument(doc);
        } else {
            // Existing index (an old copy of this document may have been indexed) so 
            // we use updateDocument instead to replace the old one matching the exact 
            // path, if present:
            System.out.println("updating " + file);
            writer.updateDocument(new Term("path", file.toString()), doc);
        }
    }
}